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Year Author Title Journal/Proceedings
2018 Jayawant, R., Avetian, T., McRobb, N. and Shultz, R. Development and Certification of a Skid Mounted AMB Controller for Hazardous Area Installation Proceedings of ISMB16  
Abstract: Active magnetic bearing (AMB) controllers for hydrocarbon and other hazardous area applications are normally installed within a control room inside a safe (unclassified) area. This article describes the design and certification of an AMB controller for skid mounting within the hazardous area, drawing on recent development of a first of class system. The design challenges raised by the environmental requirements for outdoor installation are discussed together with the challenges resulting from the hazardous area certification requirements. The routes to hazardous area certification considered during the early phases of the development project are presented together with a description of the route finally chosen.
BibTeX:
@inproceedings{ISMB16_001,
  author = {Richard Jayawant and Tadeh Avetian and Nigel McRobb and Richard Shultz},
  title = {Development and Certification of a Skid Mounted AMB Controller for Hazardous Area Installation},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_001.pdf}
}
2018 Gloess, R. and Goos, A. Nanometer Resolution of Magnetic Levitation Stages for Planar and Linear Scan Application Proceedings of ISMB16  
Abstract: This article describes the design rules for the magnetic constraints, the sensors, and the controller for planar and linear stages for a scan application with nanometer resolution. For a new planar maglev system, it is shown that very low- and high-resolution optical incremental sensor heads can be used in small gaps inside and below the PCB. The “inside coils sensor” design leads to nonlinearities in the force generation. The article shows that the resulting nonlinearities can be eliminated by a current pre-shaping method. It is also shown that it is possible to use only incremental encoders for linear maglev scan modules as well as for gantry maglev systems, and that this is necessary for low-price area in high-precision automation.
BibTeX:
@inproceedings{ISMB16_002,
  author = {Rainer Gloess and Alexander Goos},
  title = {Nanometer Resolution of Magnetic Levitation Stages for Planar and Linear Scan Application},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_002.pdf}
}
2018 Oguri, Y., Kajisawa, Y., Oka, K. and Harada, A. Development of MC Type Magnetic Levitation System Using Resonance Type Contactless Power Supply Proceedings of ISMB16  
Abstract: This research focuses on A MC type Lorentz force magnetic levitation system using resonance type contactless power supply. A novel prototype of the levitation system is designed and implemented. In addition, control analysis and experimental verification of a practical levitation system are conducted to demonstrate the validity of the proposed system.
BibTeX:
@inproceedings{ISMB16_003,
  author = {Yuto Oguri and Yusuke Kajisawa and Koichi Oka and Akinori Harada},
  title = {Development of MC Type Magnetic Levitation System Using Resonance Type Contactless Power Supply},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_003.pdf}
}
2018 Franz, D., Schneider, M., Richter, M. and Rinderknecht, S. Magnetically Levitated Spindle for Long Term Testing of Fiber Reinforced Plastic Proceedings of ISMB16  
Abstract: This article describes a magnetically levitated spindle for long term cyclic fatigue strength testing of cylinders made of fiber reinforced plastic. These cylinders represent the outer-rotor of a kinetic energy storage. The realized spindle design has multiple eigenmodes below the operational speed range, which are described in the first part of this paper. Because the system is operated under vacuum conditions, the second part of this paper focuses on the heat generation and distribution on the rotor during operation. First, transient electromagnetic finite element simulations are described for the active magnetic bearings. These simulations are used to derive power losses of the active components on the rotor. Second, a finite element simulation characterizes the thermal behavior of the rotor and includes thermal radiation and conduction. Using the power losses calculated in the electromagnetic simulation, the thermal simulation provides the temperature of the rotor. Finally, these results are compared with measured data from the spindle. The comparison shows that the losses in the upper bearings are underestimated by the electromagnetic simulation. Nevertheless, the simulations show that the rotor overheats during long term operation, and thus further improvements on the control of the system have to be carried out.
BibTeX:
@inproceedings{ISMB16_004,
  author = {Daniel Franz and Maximilian Schneider and Michael Richter and Stephan Rinderknecht},
  title = {Magnetically Levitated Spindle for Long Term Testing of Fiber Reinforced Plastic},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_004.pdf}
}
2018 Noh, M.D., Jung, J., Lee, N.S., Jang, S., Lee, K. and Kim, S. Development of Oil-Free Turbo-Chillers Equipped With Magnetically-Levitated Compressors Proceedings of ISMB16  
Abstract: The chiller market has increasingly adopted oil-free technology due to the ease of maintenance and the use of variable-speed direct drive. Oil-free bearings also eliminate the possibility of contaminating refrigerant with lubricating oil, resulting in the prolonged use of refrigerant and avoiding performance degradation. In this paper, the development of oilfree chillers which have been recently introduced in the market is described. The centrifugal compressor of the chiller is equipped with active magnetic bearings: two radial bearings and one thrust bearing. We present some results of performance validation tests.
BibTeX:
@inproceedings{ISMB16_005,
  author = {Myounggyu D. Noh and Jinhee Jung and Nam Soo Lee and Sungmin Jang and Kiwook Lee and Soyoon Kim},
  title = {Development of Oil-Free Turbo-Chillers Equipped With Magnetically-Levitated Compressors},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_005.pdf}
}
2018 Guo, Z., Qian, M., Wang, H., Masala, A., Shultz, R.R., Yang, W., Lu, H. and Yang, T. Commissioning and Testing of Active Magnetic Bearings for HTR Production Fuel Ball Blowers Proceedings of ISMB16  
Abstract: High temperature gas cooled reactor (HTR) nuclear power plants depend on high-performance fluid machinery, including helium circulators and fuel ball blowers, for safe, reliable and efficient operation. Active magnetic bearings (AMB) have been utilized in all recent high temperature helium-cooled reactor designs as the only mature oil-free bearing technology to provide high reliability and availability of operations for these highly demanding applications. With the successful operation of the prototype, HTR production fuel ball blowers have been manufactured and the commissioning and qualification testing have been recently completed. This paper describes the technical challenges, solutions and results in the commissioning phase, and the qualification testing of the HTR production fuel ball blowers. The qualification testing included running the machine with helium gas to ensure the cooling and thermal conditions of the machine were stable at the maximum speed condition. The bearing temperatures, vibration levels and bearing dynamic loads were measured and were all as expected. In addition, five full speed landings were successfully performed on one of the production fuel ball blower machines.
BibTeX:
@inproceedings{ISMB16_006,
  author = {Zenglin Guo and Minlong Qian and Hong Wang and Andrea Masala and Richard R. Shultz and Weichang Yang and Haifei Lu and Tao Yang},
  title = {Commissioning and Testing of Active Magnetic Bearings for HTR Production Fuel Ball Blowers},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_006.pdf}
}
2018 Keogh, P., Aeschlimann, B., Hawkins, L., Jayawant, R., Koehler, B.-U. and Maslen, E. Activities of ISO/TC 108/SC 2/WG 7 in the Development of Standards for AMB Systems Proceedings of ISMB16  
Abstract: ISO/TC 108/SC 2/WG 7 is the official working group of the International Organization for Standardization (ISO) that deals with the setting of standards for Active Magnetic Bearing (AMB) equipped rotating machinery. Since 2002, four parts have been developed for ISO 14839 covering Vocabulary (Part 1), Evaluation of Vibration (Part 2), Evaluation of Stability Margin (Part 3), and Technical Guidelines (Part 4). This paper will provide an update on progress for Touchdown Bearings for Rotating Machinery Equipped with Active Magnetic Bearings (Part 5). The paper will also provide an overview of the expected future development of the standard, including the important issues that need to be addressed in the design process.
BibTeX:
@inproceedings{ISMB16_007,
  author = {Patrick Keogh and Beat Aeschlimann and Larry Hawkins and Richard Jayawant and Bert-Uwe Koehler and Eric Maslen},
  title = {Activities of ISO/TC 108/SC 2/WG 7 in the Development of Standards for AMB Systems},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_007.pdf}
}
2018 Khatri, R. and Hawkins, L. Applicability of API 617 8th ed. and ISO 14839-3 in Evaluating the Dynamics Stability of AMB-Supported Compressors Proceedings of ISMB16  
Abstract: Oil & Gas (O&G) original equipment manufacturers (OEMs) have long used API 617 as the international standard of choice to guide turbomachinery rotordynamics requirements. Recently, the O&G industry has experienced a growing interest in applying active magnetic bearings (AMB) in high-speed applications, hermetically-sealed applications, and compressors with a large performance envelope. As such, the API 617 standards have recently been expanded to include a section (API 617, 8th ed., “Annex E”) regarding evaluation of magneticbearing- supported compressors. New standards included in Annex E both compliment and compromise existing, wellregarded international magnetic bearing rotordynamics standards, namely ISO 14839-3. This paper reviews and compares the dynamics requirements included in API 617 8th edition Annex E with those of ISO 14839-3. Notable, this paper compares the stability criteria of both standards by simulating the synchronous response, sensitivity transfer function, and closedloop transfer function of simple 1-D dynamic systems.
BibTeX:
@inproceedings{ISMB16_008,
  author = {Rasish Khatri and Larry Hawkins},
  title = {Applicability of API 617 8th ed. and ISO 14839-3 in Evaluating the Dynamics Stability of AMB-Supported Compressors},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_008.pdf}
}
2018 Lin, J., Harada, A. and Oka, K. Novel System for Zero-Power, Orientation-Controlled Magnetic Levetation Proceedings of ISMB16  
Abstract: A novel system is described for achieving orientation controlled zero power levitation. The principles of operation are explained, as well as the zero power feedback control strategy. Expected system limitations and system parameter selection is discussed. Numerical data is presented in support of the feasibility of the system and controller.
BibTeX:
@inproceedings{ISMB16_009,
  author = {James Lin and Akinori Harada and Koichi Oka},
  title = {Novel System for Zero-Power, Orientation-Controlled Magnetic Levetation},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_009.pdf}
}
2018 Tomida, M., Oka, K., Harada, A. and Lin, J. 3phase Linear Actuator in Magnetically Lavitated Linear Slider with Non-contact Power Supply Proceedings of ISMB16  
Abstract: This paper presents a linear actuator which magnetically levitated a linear motor using non-contact power supply. A prototype of the system is designed and implemented. The simulation results confirm the validity of the proposed system
BibTeX:
@inproceedings{ISMB16_010,
  author = {Masahiro Tomida and Koichi Oka and Akinori Harada and James Lin},
  title = {3phase Linear Actuator in Magnetically Lavitated Linear Slider with Non-contact Power Supply},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_010.pdf}
}
2018 Proell, A.J., Sloupensky, J., Dirnberger, P. and Amrhein, W. Testing the High Speed Shaft of a Yarn Spinning System with a Magnetic Bearing Test Device Proceedings of ISMB16  
Abstract: This article describes the possibility and advantages of testing the high speed shaft of yarn spinning regarding its balancing and magnetic behavior by the help of magnetic bearings. The device under investigation is part of a high speed drive which contains magnetic bearings as well.
BibTeX:
@inproceedings{ISMB16_011,
  author = {Andreas J. Proell and Jiri Sloupensky and Peter Dirnberger and Wolfgang Amrhein},
  title = {Testing the High Speed Shaft of a Yarn Spinning System with a Magnetic Bearing Test Device},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_011.pdf}
}
2018 Wang, H. and Liu, K. Study of a Magnetic Suspended Flywheel Energy Storage System for Pulsed Power Proceedings of ISMB16  
Abstract: Flywheel Energy Storage Systems (FESS) are found in a variety of applications ranging from grid-connected energy management to uninterruptible power supplies. This article describes the application of FESS in high pulsed power area. The rotor of FESS for puled power is generally supported by the traditional bearings, which are considered as a source of friction during rotation, and require lubrication and high maintenance, and can’t be used at high speed ranges. In this paper, a magnetic suspended flywheel energy storage system (MSFESS) is proposed and designed for the pulsed power applications. Topology, principle and discharging model of the MSFESS are introduced and studied. The impacts of the high power pulsed discharge on the magnetic bearing system are analyzed. Scaled prototype of the MSFESS is manufactured and tested.
BibTeX:
@inproceedings{ISMB16_012,
  author = {Haoze Wang and Kun Liu},
  title = {Study of a Magnetic Suspended Flywheel Energy Storage System for Pulsed Power},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_012.pdf}
}
2018 Pesch, A.H. and Scavelli, P.N. Condition Monitoring of AMBs on the IoT Proceedings of ISMB16  
Abstract: The Internet of Things (IoT) is the interconnection of physical devices enabling them to send and receive data over the internet. Using the IoT enables connected devices to acquire new capabilities. IoT technology has rapidly increased over the last decade and is being applied to industrial devices. AMBs are naturally apt to the IoT due to their inherent sensors and actuators. This study develops a method for the condition monitoring of AMB systems online using off-the-shelf IoT technology and custom software. In this study, a MBC500 AMB test rig is outfitted with a Raspberry Pi single board computer. The Raspberry Pi monitors the AMB’s position sensors and current sensors via an ADS1115 analog-to-digital converter. This setup allows users to remotely access the system and monitor its condition. Several typical rotordynamic malfunctions are imposed on the experimental test rig and diagnosed remotely, demonstrating the efficacy of the technique. The malfunctions include static loading and static and dynamic unbalance.
BibTeX:
@inproceedings{ISMB16_013,
  author = {Alexander H. Pesch and Peter N. Scavelli},
  title = {Condition Monitoring of AMBs on the IoT},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_013.pdf}
}
2018 Zhang, W., Ji, C. and Wang, T. Study on the Nonlinear Suspension Characteristic of Magnetic Suspended Vibration Isolator Proceedings of ISMB16  
Abstract: The definition of stiffness and damping for magnetic suspended vibration isolator was proposed in this paper. The coupling relationship between system controller parameters, mechanical structure parameters and dynamic stiffness is revealed by studying the nonlinear stiffness and damping of magnetic suspension vibration isolator. The frequency domain characteristics of nonlinear stiffness of magnetic suspended vibration isolator are studied combined PID control law. The results show that the system has high support stiffness in low frequency and high frequency bands. The amplitude-frequency characteristics of lower stiffness in middle frequency band are bathtub-shaped. The dynamic stiffness of the system can flexibly designed by changing the controller parameters in the stable region of the system.
BibTeX:
@inproceedings{ISMB16_014,
  author = {Weiwei Zhang and Cuicui Ji and Tingting Wang},
  title = {Study on the Nonlinear Suspension Characteristic of Magnetic Suspended Vibration Isolator},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_014.pdf}
}
2018 Pilat, A.K. and Klocek, J. Investigation of Programmable Automation Controller for AMB Applications Proceedings of ISMB16  
Abstract: This article presents a results of selected hardware investigation done using the Programmable Automation Controller (PAC), The Device was placed at the laboratory test rig consisting of programmable devices: signal generator, oscilloscope, load. The controller was tested with respect to the requirements of active levitation devices. The analog power actuator was investigated and results are given in a form of plot diagrams.
BibTeX:
@inproceedings{ISMB16_015,
  author = {Adam Krzysztof Pilat and Jakub Klocek},
  title = {Investigation of Programmable Automation Controller for AMB Applications},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_015.pdf}
}
2018 Tang, J., Li, Q., Sun, F., Zhao, C., Jin, J., Guo, Y. and Xu, F. Anti-fall-attract Control of a Permanent Magnetism Suspension System with Flux Path Control Proceedings of ISMB16  
Abstract: Permanent magnetic levitation is a typical nonlinear system. With the air gap between magnetic conductors and suspensions object is changed, the control characteristics changes and affects the stability of the system. In order to prevent the external interference causing the suspended object falls or attract on it,as the system deviating from the equilibrium point. Anti-fall- Attract Control method based on air gap variation is proposed. According to the selection of multiple design points in the whole air gap, a gain regulation is designed at each design point. Finally, a complete anti-fall and antiattract control law is obtained by interpolating between these linear controllers,which improves the controllability,stability and robustness of the system. The simulation and experimental results show that the anti-fall and anti-attract control method can effectively compensate for the uneven variation of suspension force when the suspension is moving. External disturbance causes the air gap large, suspension force is increased rapidly, the suspension object can be prevented from falling;External disturbance causes the air gap smaller, suspension force is reduced quickly, the suspension object can be prevented attract to magnetic conductors.
BibTeX:
@inproceedings{ISMB16_016,
  author = {Jinghu Tang and Qiang Li and Feng Sun and Chuan Zhao and Junjie Jin and Yongquan Guo and Fangchao Xu},
  title = {Anti-fall-attract Control of a Permanent Magnetism Suspension System with Flux Path Control},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_016.pdf}
}
2018 Miao, L., Sun, F., Wei, W., Zhao, Z., Li, Q., Xu, F., Pan, F. and Zhang, X. Magnetic Field Calculation and Characteristic Analysis on Double-acting VCM for Intelligent Vehicle Suspension Proceedings of ISMB16  
Abstract: For the shortcomings of MacPherson independent suspension vehicle, such as brake nod obvious, large roll, poor stability and the vibration energy dissipation of the suspension system, A kind of magnetic field structure of VCM (Voice Coil Motor) combined with active control and energy recycle is proposed. In this paper, a 3D model of the VCM is designed, and introduced the structure in detail, Secondly, the mathematical model of the VCM quasiparallel magnetic field is established, the 3D model is analyzed, aiming at the maximum flux density and limited by the size of the motor. Based on the calculation of magnetic field, the influence of each parameter on the flux density of the motor is analyzed, and the prototype is designed. The results show that magnetic field model of the VCM is verified. Deviation within the acceptable range exist between the experimental value and the theoretical value, Analyzed influencing factors of the VCM characteristics, the VCM prototype has ideal output force characteristics. It has provided an important theoretical foundation for design and development of such suspension.
BibTeX:
@inproceedings{ISMB16_017,
  author = {Liguo Miao and Feng Sun and Wei Wei and Zhiyu Zhao and Qiang Li and Fangchao Xu and Fei Pan and Xiaoyou Zhang},
  title = {Magnetic Field Calculation and Characteristic Analysis on Double-acting VCM for Intelligent Vehicle Suspension},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_017.pdf}
}
2018 Gancitano, P., Schwartz, B., Fittro, R. and Knospe, C. Development of an Active Load Cell Force Measurement Test Rig Proceedings of ISMB16  
Abstract: As industrial machine performance requirements progress, accurate high frequency fluid-film bearing coefficients are necessary in order to ensure accurate prediction of system level machine rotordynamics. Traditional fluid-film bearing test rigs have been shown to enable accurate dynamic bearing coefficient identification. However, the uncertainty of these coefficients significantly increase at higher frequencies (>250 Hz). Therefore, as modern high performance machinery require high accuracy high frequency dynamic coefficient validation, a new bearing test rig design is required. This work solves this problem through the development of a new test rig based on the development of an “Active Load Cell”. The theoretical development, test rig design and detailed simulation results are presented to demonstrate the dynamic force measurement performance capabilities of an Active Load Cell over a broad frequency range.
BibTeX:
@inproceedings{ISMB16_018,
  author = {Paul Gancitano and Benstone Schwartz and Roger Fittro and Carl Knospe},
  title = {Development of an Active Load Cell Force Measurement Test Rig},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_018.pdf}
}
2018 Song, W., Yu, C., Sun, Y. and Chen, X. Radial and Axial Integrated Auxiliary Bearing Device for Active Magnetic Bearing System Proceedings of ISMB16  
Abstract: A type of radial and axial integrated auxiliary bearing (RAIAB) device with the function of simultaneously eliminate the radial and axial protective clearance after the magnetic levitated rotor dropped is conceived and presented in this paper. In the RAIAB, the two ends of the rotor and the inner races of the RAIABs mounted in each end are machined into cone-shape coordination. Besides, a series of ball are used between the outer races of the RAIABs and the pedestal. When the active magnetic bearing works, initial protective clearances exist between the two ends of the rotor and the inner races. After AMB system failure, the auxiliary bearing driven by an additional motor to produce axial movement which makes the cone surfaces of the inner races of auxiliary bearings gradually close with each end of the rotor until the protective clearance is eliminated. Therefore, the possibility of backward whirl and impacts can be reduced. Two different cone schemes of the rotor end shape are comparatively diskussed. Furthermore, the influences the value of taper of the cone on the protective clearance between the rotor and auxiliary bearing and the axial force produced by the radial force after the rotor drop. The preliminary prototype experimental rig was developed to demonstrate the feasibility of the RAIAB.
BibTeX:
@inproceedings{ISMB16_019,
  author = {Wei Song and Chengtao Yu and Yuemei Sun and Xiuxiang Chen},
  title = {Radial and Axial Integrated Auxiliary Bearing Device for Active Magnetic Bearing System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_019.pdf}
}
2018 Li, G., Jin, C., Zhou, J. and Xia, J. Identification of Stiffness and Damping of Auto-eliminating Clearance Auxiliary Bearing Devices Based on Finite Element Method Proceedings of ISMB16  
Abstract: Abstract—In order to study the dynamic supportive stiffness and damping of auto-eliminating clearance auxiliary bearing devices (ACABD) after the rotor falls, this paper proposed an identification method of stiffness and damping based on finite element method. Fist, the model of the rotor supported by ACABD and the feasibility of the method was verified by simulation. Then, the test bench of magnetic bearing system contained the ACABD was designed. And the unbalanced responses were obtained by the experiment method of unbalanced excitation. In the end, the actual supportive stiffness and damping of ACABD were obtained by the parameter identification method based on finite element method. The results indicate that during the moderation process from 500Hz to 20Hz after the drop of the rotor, the values of supportive stiffness and damping of ACABD change continually, which generally decrease with the rotational speed.
BibTeX:
@inproceedings{ISMB16_020,
  author = {Guochang Li and Chaowu Jin and Jin Zhou and Junyu Xia},
  title = {Identification of Stiffness and Damping of Auto-eliminating Clearance Auxiliary Bearing Devices Based on Finite Element Method},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_020.pdf}
}
2018 Quurck, L., Viitala, R., Franz, D. and Rinderknecht, S. Planetary Backup Bearings for Flywheel Applications Proceedings of ISMB16  
Abstract: High-speed flywheels can be used as kinetic energy storages for electrical energy. To increase the energy density of the flywheel, an outer rotor type flywheel can be utilized. The fly-wheels are supported by magnetic bearings and operated in vac-uum conditions to provide a high efficiency. Backup bearings are needed to support the rotor in case of a malfunction of the mag-netic bearings. However, since conventional backup bearings are not available for the high surface velocities above 200 m/s of the outer rotor type flywheels, a planetary backup bearing design was introduced. The present study investigates the experimental results of two test series conducted with a planetary backup bearing test rig. The rotor having similar properties to the outer rotor type fly-wheel was consecutively delevitated at rotational speeds of 1 – 20 krpm. In order to assess the severity of the delevitation events po-sition, rotational speed, force, and thermal data were evaluated. The advancing wear of the planetary backup bearing was as-sessed with multiple methods. During the first test series, the ro-tor was mostly relevitated a few seconds after the drop-down. The second test series consisted only of full run-downs and led to a bearing failure. The results suggest that the planetary backup bearing is fea-sible in the proposed application. Multiple full run-downs were possible with neither unwanted rotor-stator contact nor damage to the rotor, magnetic bearings or electric machine. The proposed indicators were found to be applicable in the planetary backup bearing life-time assessment. The future work includes the exper-imental investigation of the planetary backup bearing in a full-scale outer rotor type kinetic energy storage.
BibTeX:
@inproceedings{ISMB16_021,
  author = {Lukas Quurck and Raine Viitala and Daniel Franz and Stephan Rinderknecht},
  title = {Planetary Backup Bearings for Flywheel Applications},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_021.pdf}
}
2018 Xia, J., Xu, L., Jin, C. and Yu, C. Performance Analysis of Auxiliary Bearing Based on Four-contact-point Ball Bearing Proceedings of ISMB16  
Abstract: The performance of auxiliary bearings based on fourcontact- point ball bearings is studied. Firstly, based on Hertz contact theory, the static model of bearing is established to analyse the influence of structural parameters on stress and strain of the contact part, and the selection range of the optimal parameters is given. Then, the mechanical analysis of fourcontact- point ball bearing under different loads is carried out, and the variation law of load distribution is studied by theoretical calculation. Finally, the dynamic model of rotor dropping is established to compare the protection effect between four-contact-point ball bearing and angular contact bearing. A test rig is built to carry out the rotor drop experiment under different bearing protection. The results could be referenced for the design of auxiliary bearings in active magnetic bearing system.
BibTeX:
@inproceedings{ISMB16_022,
  author = {Junyu Xia and Longxiang Xu and Chaowu Jin and Chengtao Yu},
  title = {Performance Analysis of Auxiliary Bearing Based on Four-contact-point Ball Bearing},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_022.pdf}
}
2018 Xu, Y., Zhu, H. and Wu, M. Modeling of Bearingless Permanent Magnet Synchronous Motor Based on Mechanical to Electrical Coordinates Transformation Proceedings of ISMB16  
Abstract: A bearingless permanent magnet synchronous motor(BPMSM) has two sets of stator windings, namely torque windings and suspension force windings, so there are two types of air-gap magnetic fields, torque windings’ and suspension force windings’, with different pole-pair in the motor. The analysis of the flux linkage intersection between the two sets of the windings is the foundation of setting up the precise mathematical model of the motor. By the application of mechanical-to-electrical coordinate transformation, this paper refers to a detailed analysis of the flux linkage intersection between torque windings and suspension force windings. And it has been proved that if the pole-pair of torque windings and suspension force windings are PM=1 and PB=2, respectively (or PB=1, PM=2), flux linkage of the torque windings and suspension force windings will be mutual coupling. The whole proof is simple, objective and easy to understand with a clear concept. What’s more, based on the conclusions proved above, the general mathematical model of BPMSM is set up. Finally, the experiment results have shown that the established mathematical model is feasible and accurate.
BibTeX:
@inproceedings{ISMB16_023,
  author = {Ying Xu and Huangqiu Zhu and Mengyao Wu},
  title = {Modeling of Bearingless Permanent Magnet Synchronous Motor Based on Mechanical to Electrical Coordinates Transformation},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_023.pdf}
}
2018 Doenni, E., Achtnich, T. and Zwyssig, C. Vibration Suppression of a Slotless Self-Bearing Permanent-Magnet Motor for Optical Applications Proceedings of ISMB16  
Abstract: Magnetic bearings, particularly of slotless type, are ideally suited for optical applications by enabling operation in vacuum at high speeds with high lifetime, avoiding particle generation and allowing active control, and therefore suppression of bearing stator force and rotor displacements. In this paper, different approaches for vibration suppression are compared and experimentally verified with a dual hetero-/homopolar slotless self-bearing motor. A feed forward has advantages compared to a notch-filter approach as it allows rotor vibration suppression and lowering the stator vibration suppression activation speed into the rigid-rotor critical speed range. Finally, the rotational speed fluctuations, important for optical applications, are investigated.
BibTeX:
@inproceedings{ISMB16_024,
  author = {Elias Doenni and Timon Achtnich and Christof Zwyssig},
  title = {Vibration Suppression of a Slotless Self-Bearing Permanent-Magnet Motor for Optical Applications},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_024.pdf}
}
2018 Jin, Z., Sun, X. and Yang, Z. Design and Control of a Novel Four-degree of freedom Bearingless Permanent Magnet Machine for Flywheel Energy Storage System Proceedings of ISMB16  
Abstract: In this paper, a novel bearingless permanent magnet machine (BPMM) without strong and complex magnetic field coupling, which can limit four degrees-of-freedom (DOFs) independently, is presented for the flywheel energy storage system (FESS). The proposed machine provides suspension force by means of interaction of flux density of permanent magnet rings and winding current. And the model of the proposed machine is derived. Meanwhile, based on the conventional cross feedback control, the modified control scheme with compensation for cross channels is illustrated. Additionally, combining with the machine model and modified cross feedback controller, the simulation is built to demonstrate the effectiveness. The results show smaller fluctuation in steady state, fast response with disturbance and less impact on undisturbed channels by employing the modified control.
BibTeX:
@inproceedings{ISMB16_025,
  author = {Zhijia Jin and Xiaodong Sun and Zebin Yang},
  title = {Design and Control of a Novel Four-degree of freedom Bearingless Permanent Magnet Machine for Flywheel Energy Storage System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_025.pdf}
}
2018 Tanii, I., Makita, K., Oka, K. and Harada, A. Development of Bearingless Motor with Non-contact Power Supply Levitation Performance Proceedings of ISMB16  
Abstract: This paper presents a new type of bearing-less motor. A unique feature of this bearing-less motor is an operation without the utilization of permanent magnets. The rotor magnetized by a current of a non-contact power supply, which consists of a bridge rectifier circuit and coils. In previously report, the levitation is archived through attractive forces generated by inclinations on the edges of the rotor and the stator. Hence, this paper shows the experimental result of the levitation and rotation control of a bearing-less motor with non-contact power supply. In addition, the design descriptions of a new rotor improvement for achieving the target rotation performance is given.
BibTeX:
@inproceedings{ISMB16_026,
  author = {Isao Tanii and Kazuma Makita and Koichi Oka and Akinori Harada},
  title = {Development of Bearingless Motor with Non-contact Power Supply Levitation Performance},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_026.pdf}
}
2018 Osa, M., Masuzawa, T., Orihara, R. and Tatsumi, E. Magnetic Suspension Performance Enhancement of Ultra-compact 5-DOF Controlled Self-bearing Motor for Rotary Pediatric Ventricular Assist Device Proceedings of ISMB16  
Abstract: Research interests of the compact magnetically levitated motor have been strongly increased in development of durable and biocompatible mechanical circulatory support (MCS) devices for pediatric heart disease patients. In this study, a tiny axial gap type 5-degrees of freedom (DOF) controlled selfbearing motor for use in pediatric MCS devices has been developed. The motor consists of two identical motor stators and a centrifugal levitated rotor. This paper investigated design improvement of the magnetic circuit for the developing selfbearing motor to enhance the magnetic suspension and rotation performance. The motor geometries were refined by using numerical calculation and three-dimensional magnetic field analysis. The modified motor can achieve the higher suspension force and torque characteristics than the previously developed motor, and indicates stable magnetic suspension performance up to the rotating speed of 8000 rpm.
BibTeX:
@inproceedings{ISMB16_027,
  author = {Masahiro Osa and Toru Masuzawa and Ryoga Orihara and Eisuke Tatsumi},
  title = {Magnetic Suspension Performance Enhancement of Ultra-compact 5-DOF Controlled Self-bearing Motor for Rotary Pediatric Ventricular Assist Device},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_027.pdf}
}
2018 Kluyskens, V., Verdeghem, J.V., Dumont, C. and Dehez, B. Experimental Investigations on a Heteropolar Electrodynamic Bearing-self-bearing Motor Proceedings of ISMB16  
Abstract: This article describes how multifunction windings can passively generate electrodynamic centering forces and when fed by a power supply, a driving torque. It shows the experimental EMF measures, both for the electrodynamic centering and for the motor functions, obtained on a prototype, operating in quasi-static conditions. It also shows the measured radial forces and the measured torque in these conditions.
BibTeX:
@inproceedings{ISMB16_028,
  author = {Virginie Kluyskens and Joachim Van Verdeghem and Corentin Dumont and Bruno Dehez},
  title = {Experimental Investigations on a Heteropolar Electrodynamic Bearing-self-bearing Motor},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_028.pdf}
}
2018 Ahmed, F. and Kalita, K. Controllability of Radial Displacement in Bearingless Switched Reluctance Motor with Bridge Configured Winding Proceedings of ISMB16  
Abstract: Due to the salient features of stator and rotor in Switched Reluctance Motor the air-gap of the machine does not remain uniform during its motoring operation. This innate characteristic is responsible in producing considerable amount of radial force in the motor. However on the other hand eccentricity or radial displacement of the rotor is another key cause to this production of radial force. In this paper a single winding structure called bridged configured winding in a 12/8 BSRM is delineated which can be used to deploy the radial displacement by injecting controlled current within the same winding. Initially a mathematical model of the motor is developed and verified using finite element modeling. The developed model is analyzed by integrating a voltage source asymmetric converter for motoring operation and separate asymmetric converters for injecting currents into the winding to control the radial displacement of the motor. Investigations of radial forces at various rotational positions and controllability of radial displacement are carried out using a simple PID controller system.
BibTeX:
@inproceedings{ISMB16_029,
  author = {Firdausa Ahmed and Karuna Kalita},
  title = {Controllability of Radial Displacement in Bearingless Switched Reluctance Motor with Bridge Configured Winding},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_029.pdf}
}
2018 gu Kang, Y. and Severson, E.L. Optimization Framework for a Large, High Speed Bearingless Permanent Magnet Motor Proceedings of ISMB16  
Abstract: Recently, there has been increased research interest in developing higher power bearingless motors. To reach significant power levels, rigorous design optimization is needed. This paper investigates the electromagnetic design space for a 30k r/min, 50kW bearingless permanent magnet motor. The differential evolution optimization algorithm is used to optimize two different design topologies for various objective functions. Detailed modeling considerations are presented to calculate the key performance metrics which are unique to bearingless motor designs (i.e., average and ripple suspension forces) in a computationally efficient manner. The resulting optimal design geometry is compared to demonstrate the wide design space of this machine. Finally, a weighted multi-objective function is proposed based on efficiency, force and torque ripple, and power density.
BibTeX:
@inproceedings{ISMB16_030,
  author = {Ye gu Kang and Eric L. Severson},
  title = {Optimization Framework for a Large, High Speed Bearingless Permanent Magnet Motor},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_030.pdf}
}
2018 Noh, M., Gruber, W., Speakman, J., Gartner, M.J. and Trumper, D.L. Homopolar Bearingless Slice Motors Driving Reluctance Rotors Proceedings of ISMB16  
Abstract: We present a bearingless slice motor that levitates and rotates a magnet-free solid-steel reluctance rotor. The motor stator uses permanent-magnet arrays near the tips of the stator teeth to provide the rotor with a homopolar bias flux. The magnet arrays are in a Halbach configuration to improve the rotor passive stiffness. The reluctance rotor has two radial fins, at the top and bottom surfaces, through which the bias flux from the magnet arrays enters. The homopolar bias flux exits the rotor via four salient rotor teeth located between the rotor radial fins. The bias flux passively stabilizes the rotor in the axial translation and in the out-of-plane tilts. The two radial translations are actively stabilized via feedback control. The stator winding consists of two sets of three-phase windings. One set of windings generates two-pole magnetomotive force (MMF) for levitation control, and the other set of windings generates eight-pole MMF for rotation control. Finite element analyses are performed to compute the performance estimates, and a prototype system is built and tested for the take-off, levitation, and rotation capabilities.
BibTeX:
@inproceedings{ISMB16_031,
  author = {Minkyun Noh and Wolfgang Gruber and Jeff Speakman and Mark J. Gartner and David L. Trumper},
  title = {Homopolar Bearingless Slice Motors Driving Reluctance Rotors},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_031.pdf}
}
2018 Liu, Z. and Chiba, A. Optimum Pole Number Combination for High-Speed High-Power BPM Bearingless Motor Proceedings of ISMB16  
Abstract: Pole number combination of torque and suspension winding is essential for bearingless motors. In this paper, the comparison of the performance of a high-speed high-power buried permanent magnet bearingless motor with different pole combinations is presented. The power factor, efficiency, suspension force amplitude, fluctuation and eddy current are compared for a 35 kW unit.
BibTeX:
@inproceedings{ISMB16_032,
  author = {Zongwei Liu and Akira Chiba},
  title = {Optimum Pole Number Combination for High-Speed High-Power BPM Bearingless Motor},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_032.pdf}
}
2018 Luo, Y., Chen, J., Zhang, L., Zhang, H. and Liu, J. Fitting of Dynamic Characters for Magnetic Bearing Control System by Using Deep Neural Network Proceedings of ISMB16  
Abstract: Magnetic Bearing Control System(MBCS)has two major aporias , non-linear and strong coupling. Most of the traditional methods are severely weakened by these two problems. This paper presents a noval control algorithm to optimize the performance of Magnetic Bearing Control System 。The proposed method estimates the non-linear dynamic characters and decouples system by using a deep neural network ( DNN ) .The inputs of DNN are system PID controller parameters and some other dynamic coefficients , outputs are Magnetic Bearing speed,torque and power output characters. We utilize root-mean-square error(RMSE)as the loss function of DNN since the network is a regression model . Experiments showed that the proposed method could affectively fit and decouple dynamic characters for MBCS and performs competitively against Humans.
BibTeX:
@inproceedings{ISMB16_033,
  author = {Yanyan Luo and Jinping Chen and Li Zhang and Haining Zhang and Jun Liu},
  title = {Fitting of Dynamic Characters for Magnetic Bearing Control System by Using Deep Neural Network},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_033.pdf}
}
2018 He, J., Deng, Z., Peng, C. and Li, K. Optimal Vibration Control for a Centrifugal Compressor with Magnetic Bearings by a Phase-shift Notch Filter Proceedings of ISMB16  
Abstract: Undesired vibration caused by mass imbalance is common for a centrifugal compressor supported by magnetic bearings. It poses a potential threat to system stability and operation performance. In this work, a phase-shift notch filter is adopted to suppress the synchronous vibration and stability analysis is given to ensure the system stability in the varying speed range. In order to achieve optimal dynamic performance of vibration control, the objective function is set up based on the time domain response of current, and the optimal notch filter is obtained based on the minimization of the objective function value. Finally, the effectiveness of the proposed optimal notch filter on the advancement of dynamic performance is validated through simulation results.
BibTeX:
@inproceedings{ISMB16_034,
  author = {Jiaxi He and Zhiquan Deng and Cong Peng and Kexiang Li},
  title = {Optimal Vibration Control for a Centrifugal Compressor with Magnetic Bearings by a Phase-shift Notch Filter},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_034.pdf}
}
2018 Zhang, H., Chen, J., Liu, J., Luo, Y. and Zhang, L. Research of PID Control Simulation of Magnetic Bearing System Based on Labview Proceedings of ISMB16  
Abstract: Active magnetic bearing system is a run-time control system,using NI LabVIEW which is a software platform with the features of modifing the parameters easily and applicating the codes conveniently to simulate the PID control algorithm of active magnetic bearing system. In this paper, we designed PID control algorithm and did simulation for active magnetic bearing system.This paper presents the mixed program between LabView and MatLab based on MatLab Script by the interface of LabView for Active magnetic bearing system simulation. The results of simulation show that the PID control algorithms has good dynamic and stability for active magnetic bearing system;With the Com technology, the LabView program can get more powerful algorithm supports from MatLab. The mixed programming of MatLab and LabView combines the advantages of both and makes it very promising in the engineering system.
BibTeX:
@inproceedings{ISMB16_035,
  author = {Haining Zhang and Jinping Chen and Jun Liu and Yanyan Luo and Li Zhang},
  title = {Research of PID Control Simulation of Magnetic Bearing System Based on Labview},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_035.pdf}
}
2018 Jarroux, C., Mahfoud, J., Defoy, B. and Alban, T. Control Investigations of Rotor Supported by AMBs During Severe Foundation Excitations Proceedings of ISMB16  
Abstract: The study is devoted to numerical and experimental investigations of the dynamic behavior of base excited rotating machines supported by Active Magnetic Bearings (AMBs). In case of strong base motions, the rotor can contact its touchdown bearings (TDBs) which are emergency bearings. The objective is to analyze the effect of the combination of mass unbalance forces, base motion excitations and contact nonlinearities on a rotor-AMB system response. In particular, the capacity of an augmented PID controller to maintain the system stable. FE method was developed to model the on-board rotor-AMB system. An academic scale test rig was used for the experimental investigations. Predicted and measured responses due to impulse excitations applied on the foundations were compared. The capacity of the controller to maintain the system stability is discussed.
BibTeX:
@inproceedings{ISMB16_036,
  author = {Clement Jarroux and Jarir Mahfoud and Benjamin Defoy and Thomas Alban},
  title = {Control Investigations of Rotor Supported by AMBs During Severe Foundation Excitations},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_036.pdf}
}
2018 Aeschlimann, B. and Hubatka, M. Unbalance Control of Active Magnetic Bearings Proceedings of ISMB16  
Abstract: Unbalance forces are a major source of undesired vibrations in rotating machinery. Active magnetic bearings (AMBs) with special control algorithms, allow for controlling those forces and counteract appropriately. The two basic principles are UFRC and UFCC. They are known for many years and have been published and patented before. There exist excellent publications treating the closed-loop stability of UFRC but not much can be found on the stability of UFCC. This paper presents an adaptive multi-variable implementation of UFCC, its theoretical background and a proof of control stability. UFCC as described in this paper, has shown excellent stability in practice and it can therefore be engaged over the entire speed range of the machine. However in order to minimize the load on power amplifiers and other components a switching strategy is advised, where UFRC and UFCC are switched on and off in the speed ranges where required. Guidelines for tuning UFCC parameter are also given. The effectiveness of UFCC has been proven in several applications and measurement results are given in this paper.
BibTeX:
@inproceedings{ISMB16_037,
  author = {Beat Aeschlimann and Michael Hubatka},
  title = {Unbalance Control of Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_037.pdf}
}
2018 Li, S., Deng, Z., Li, K. and He, J. A Novel SVPWM Control Algorithm for Switching Power Amplifier of Active Magnetic Bearings Proceedings of ISMB16  
Abstract: Space vector pulse width modulation (SVPWM) control algorithm is commonly used for power electronic converters. This control method can be applied to two-phase threeleg switching power amplifier for two degree-of-freedom (DOF) control coils, reducing the number of switching tubes and increasing the power density of the control systems. The reference voltage of SVPWM is usually calculated by PID controller. However, the PID parameters are difficult to adjust, and there will be chaos phenomenon. A new control method was proposed in this paper. Digital one-cycle control algorithm was used to calculate the reference voltage for SVPWM, which has the advantages of simple structure, high control accuracy, rapid response and no overshoot. Besides, In order to improve the control accuracy, a one-cycle algorithm model was established considering the resistance of magnetic bearing coil. Simulation proves that with this control strategy, the current closed-loop control has an ideal performance.
BibTeX:
@inproceedings{ISMB16_038,
  author = {Shiwen Li and Zhiquan Deng and Kexiang Li and Jiaxi He},
  title = {A Novel SVPWM Control Algorithm for Switching Power Amplifier of Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_038.pdf}
}
2018 Li, K., Deng, Z., Peng, C. and He, J. Field Dynamic Balancing for AMBs Supporting Rotor Shaft Based on Extended State Observer Proceedings of ISMB16  
Abstract: There are promising applications for high rotational speed machines supported by active magnetic bearings (AMB), whereas it is inevitable that the rotor shafts own unbalance masses more or less. Field dynamic balancing based on disturbance observer was proposed, which could effectively eliminate vibrations derived from unbalances. A band-pass filter was cascaded after the observer, which could weaken the effects from harmonic or noise disturbances. Frequency responses were measured to compensate the characteristics of the observation module to enhance the accuracy. With the precise identification results, rotor dynamic balancing could be carried out to revise the unbalances, which was verified by simulation results.
BibTeX:
@inproceedings{ISMB16_039,
  author = {Kexiang Li and Zhiquan Deng and Cong Peng and Jiaxi He},
  title = {Field Dynamic Balancing for AMBs Supporting Rotor Shaft Based on Extended State Observer},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_039.pdf}
}
2018 Di, L. and Lin, Z. Robust mu Synthesis Control Design for a High Speed Integrated Motor/Compressor System Supported by AMBs Proceedings of ISMB16  
Abstract: Active magnetic beatings (AMBs) have been gradually adopted in high-speed rotating machinery applications and the control design plays a critical role in AMB systems. The mu-synthesis control is one of the most sophisticated robust control design methods and it considers both robust stability and performance. The resulting controller is able to handle uncertainties in the dynamic system and achieve required performance and stability margin, which makes it an ideal solution for AMB control problems. However, since mu-synthesis control design directly depends on the dynamic model, an accurate modeling process of the AMB system needs to be performed prior to the controller design. In this research, we apply the robust mu-synthesis control design to a high speed integrated motor/compressor system supported by AMBs. It briefly describes the modeling of the test rig, summarizes the mu-synthesis control design process and presents the control simulation results. The simulation results have shown that the designed mu-synthesis controller is able to achieve strong control performance as well as strong robustness for the analyzed AMB system.
BibTeX:
@inproceedings{ISMB16_040,
  author = {Long Di and Zongli Lin},
  title = {Robust mu Synthesis Control Design for a High Speed Integrated Motor/Compressor System Supported by AMBs},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_040.pdf}
}
2018 Liebfried, R. and Hofmann, W. Performance of Flux Density Based Control Approaches for Active Magnetic Bearings – an Overview Proceedings of ISMB16  
Abstract: Direct flux density control of active magnetic bearings is a promising approach to increase controller accuracy or reduce the system’s price. New, ultra-thin Bismuth Hall Sensors provide the possibility to measure the air gap flux density directly. The paper presents the modelling of different bearing types and compares different control approaches with flux density measurement.
BibTeX:
@inproceedings{ISMB16_041,
  author = {Robin Liebfried and Wilfried Hofmann},
  title = {Performance of Flux Density Based Control Approaches for Active Magnetic Bearings – an Overview},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_041.pdf}
}
2018 Huang, W., Deng, Z., Peng, C., Li, K., Cai, K. and Mei, L. A Method of Suppressing Unbalance Vibration of AMBs Based on Flux Feedback Control Proceedings of ISMB16  
Abstract: In this paper, an unbalance vibration suppression method based on flux feedback control strategy is proposed. The air gap flux is obtained from an improved flux observer. The principle of generalized notch filter is analyzed in detail and the transmission matrix parameters are reasonably designed so that the system can keep stable in a wide speed range. The simulation results show that adding generalized notch filter algorithm into the control system can restrain the vibration force caused by the mass unbalance of rotor during rotation.
BibTeX:
@inproceedings{ISMB16_042,
  author = {Wei Huang and Zhiquan Deng and Cong Peng and Kexiang Li and Kaiwen Cai and Lei Mei},
  title = {A Method of Suppressing Unbalance Vibration of AMBs Based on Flux Feedback Control},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_042.pdf}
}
2018 Hubatka, M. and Aeschlimann, B. Tuning Guidelines for Generalized Notch Filters used for Unbalance Compensation for Magnetic Bearings Proceedings of ISMB16  
Abstract: Unbalance compensation in magnetic bearing control algorithms are state of the art in modern applications of active magnetic bearings. The compensation is vital to keep synchronous vibrations on the housing on a minimum level and to avoid actuator saturation. There exist different possibilities to implement the compensation in the control loop. One of it is the generalized notch filter [1]. This filter technology has been successfully used in magnetic bearings for more than 20 years. One drawback of this filter is the speed dependent parameter set. For radial bearings of a five axis rotor, the notch filter parameters are in general two dense 4x4 matrices for one rotational speed. This high demand on computational power and memory is not a problem any more for modern digital signal processors. With a well tuned parameter set the unbalance compensation can be turned on well before crossing the rigid body modes. The paper presents a novel observer based stability proof of the generalized notch filter and introduces two bode diagrams to visualize the notch filter performance and robustness. The results are verified with a simple example and on a small 5-axis test rotor system.
BibTeX:
@inproceedings{ISMB16_043,
  author = {Michael Hubatka and Beat Aeschlimann},
  title = {Tuning Guidelines for Generalized Notch Filters used for Unbalance Compensation for Magnetic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_043.pdf}
}
2018 Ueno, S., Chiba, M. and Jiang, C. Switching Control between 3-coil and 5-coil modes for 6-pole Active Magnetic Bearings Proceedings of ISMB16  
Abstract: 6-pole active magnetic bearings (AMBs) have fewer poles than usual 8-pole AMBs, then, it is easier to miniaturize and suitable for small motors. In this paper, we propose the novel control method for the 6-coil AMB, which switches between 3-coil and 5-coil modes. The 3-coil mode uses three coils to generate bearing force and can reduce power consumption. On the other hand, the 5-coil mode uses five coils, and can generate larger maximum force than that of the 3-coil mode. By switching between the two modes, it is possible to realize both lower power consumption and larger bearing force. This paper introduces the coil currents in the 5-coil mode and shows the results of levitation and rotation tests. The results show that the proposed method realizes stable levitation with lower current limit compared with other methods.
BibTeX:
@inproceedings{ISMB16_044,
  author = {Satoshi Ueno and Masayuki Chiba and Changan Jiang},
  title = {Switching Control between 3-coil and 5-coil modes for 6-pole Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_044.pdf}
}
2018 Zhou, Q., Peng, C., Zhu, M. and Deng, Z. A Novel Synchronous Rotating Frame Transformation for Complete Synchronous Vibration Force Suppression Proceedings of ISMB16  
Abstract: Unbalance vibration force is critical in normal operation of magnetic bearings. Among all vibration forces, the synchronous vibration force is the most influential factor. To effectively suppress the unbalance force caused by the mass unbalance of high-speed magnetic suspend rotor, in this work, a novel method for active magnetic bearings based on the synchronous rotating frame (SRF) transformation is adopted. In this case, the magnetic bearing force is directly set as the input of the SRF transformation. The structure and principle of SRF transformation is proposed. In order to maintain the system stability, stability analysis which is related to the SRF transformation is conducted. In order to ensure the stability of the whole close-loop system, only one parameter needs to adjust. Simulation results show that the proposed method can effectively suppress synchronous vibration force. Compared with the conventional method of vibration force suppression the method proposed has batter performance.
BibTeX:
@inproceedings{ISMB16_045,
  author = {Qian Zhou and Cong Peng and Mengting Zhu and Zhiquan Deng},
  title = {A Novel Synchronous Rotating Frame Transformation for Complete Synchronous Vibration Force Suppression},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_045.pdf}
}
2018 Rong, H., Zhou, K. and Mao, F. High-order Nonlinear Disturbance Observer Based Zero-bias Control for a Magnetic Suspended System Proceedings of ISMB16  
Abstract: In this paper, the zero-bias control method is proposed to remove the bias current/flux for the active magnetic bearing (AMB), which is meaningful to decrease the power consumption. The AMB system becomes a high nonlinear system under the zero-bias current controlled mode. Besides, the AMB suffers from lumped uncertainty including parameter uncertainty and external load, which is usually undeterminable and varying. The nonlinear disturbance observer based sliding mode control is proposed to realize the close-loop control of the whole system. Under this control framework, the structure of the controller for a nonlinear system suffered from disturbance can be divided into two parts. One is the normal sliding mode control part to achieve basic performance for the nonlinear system. The other is the compensate part to eliminate the effects caused by the unknown disturbance via disturbance observer. Compared with the methods adopting inner adaptive laws to estimate disturbance such as the adaptive backstepping sliding mode control, the nonlinear disturbance observer has much higher converging rate, which is meaningful for anti-disturbance. Mostly the nonlinear disturbance observer is adopted with the assumption that the derivative of disturbance is approximately equal to zero. In this paper, the disturbance is considered to be time varying, hence the conventional nonlinear disturbance observer is not well suited. Then the high-order nonlinear disturbance observer estimates the disturbance and its derivatives simultaneously, is proposed to handle the time varying disturbance. Under different kinds of disturbance, the high-order nonlinear disturbance observer based sliding mode control method is compared with the sliding mode control, the adaptive backstepping sliding mode control and the conventional nonlinear disturbance observer based sliding mode control. The effectiveness of the proposed high-order disturbance observer based approach for a zero-bias current controlled AMB system is verified by the simulation and experiment results.
BibTeX:
@inproceedings{ISMB16_046,
  author = {Hai Rong and Kai Zhou and Feilong Mao},
  title = {High-order Nonlinear Disturbance Observer Based Zero-bias Control for a Magnetic Suspended System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_046.pdf}
}
2018 Lyu, X., Di, L., Lin, Z., Hu, Y. and Wu, H. Performance of AMB Suspended Energy Storage Flywheel Controllers in the Presence of Time Delay Proceedings of ISMB16  
Abstract: A flywheel suspended on active magnetic bearings (AMBs) constitutes a complex system including a rotor, flywheel disks, active magnetic bearings, auxiliary bearings, a motor/generator, control systems and energy conversion systems. The complexity of AMB suspended flywheel systems often makes the construction of their test rigs too costly in a research laboratory. We recently developed an experimental platform for AMB suspended energy storage flywheel. This platform serves as a test rig to assist the analysis and control design and was developed on the basis of a flexible rotor-AMB test rig previously constructed in the Rotating Machinery and Controls (ROMAC) Laboratory, University of Virginia. Two different control designs have been implemented on this platform: the mu-synthesis control and the characteristic model based all coefficient adaptive control (ACAC). In this paper, we examine the performance of the test rig in the presence of time delays. In particular, we show by simulation that this control design possesses considerable ability to resist the effect of time delays in the control inputs and/or output measurements.
BibTeX:
@inproceedings{ISMB16_047,
  author = {Xujun Lyu and Long Di and Zongli Lin and Yefa Hu and Huachun Wu},
  title = {Performance of AMB Suspended Energy Storage Flywheel Controllers in the Presence of Time Delay},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_047.pdf}
}
2018 Yao, X., Chen, Z. and Liu, X. A Frequency Dividing Control Method Using Wavelet for Active Magnetic Bearing System Proceedings of ISMB16  
Abstract: Benefiting from the features such as zero-friction and active control, Active magnetic bearings (AMBs) have several advantages over conventional mechanical bearings and are getting more applications. Various control strategies and algorithms have been applied and designed to deal with the nonlinear characteristic as well as the complex rotor dynamics. However, most control schemes are in time domain, while the control in frequency domain, which is also essential for stability of rotor system, is rarely considered. In this paper, a frequency dividing control method is proposed for AMB-rotor system. Wavelet theory is applied for frequency dividing control. The control scheme is implemented by filter banks for Wavelet Transform (WT) and a group of PID controllers for multifrequency control. Simulation on a 4-DOF AMB-rotor system in different cases is run and vibration of the system is analyzed. Simulation results demonstrate that the proposed approach has an obvious control effect with better precision and quicker response than conventional PID control. This research provides a time-frequency control approach for AMBs, and this low-hardware-cost approach can also be adopted in other vibration control, especially in multi-frequency applications.
BibTeX:
@inproceedings{ISMB16_048,
  author = {Xuan Yao and Zhaobo Chen and Xiaoxiang Liu},
  title = {A Frequency Dividing Control Method Using Wavelet for Active Magnetic Bearing System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_048.pdf}
}
2018 Ren, G.-P., Huang, X., Wu, Y. and Zhang, H.-T. Model Predictive Control for Active Magnetic Bearings Proceedings of ISMB16  
Abstract: Active magnetic bearings (AMBs) have lots of advantages than conventional mechanical bearings so that they are being applied to various industrial rotating machineries. However, AMB system is a complex and nonlinear open-loop unstable mechatronic system. For most AMBs, the bias current of actuator is needed which means the input constraint. In this paper, a model predictive control (MPC) technique is developed for eight-pole AMB system with input constraints to improve the ability of resisting external disturbances, e.g. sensor noise and external force. And stability analysis is given and shown that this method enlarging the region of attraction. Finally, the performance of the proposed control method is verified via the simulations.
BibTeX:
@inproceedings{ISMB16_049,
  author = {Gui-Ping Ren and Xiang Huang and Yue Wu and Hai-Tao Zhang},
  title = {Model Predictive Control for Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_049.pdf}
}
2018 Zhang, Y., Liu, K., Feng, J., Wei, J. and Zhang, Z. Design and Implementation of Control System Based on DSP and FPGA for Magnetically Suspended Control Moment Gyro Proceedings of ISMB16  
Abstract: In order to implement the high stability and low vibration suspension control of magnetically suspended control moment gyro (MSCMG). This article describes the design and implementation of control system based on digital signal processor (DSP) and field programmable able gate array (FPGA) for MSCMG. The controller takes DSP as the master controller to perform the core control algorithms such as decentralized PID control, cross feedback control and adaptive notch control. The FPGA as a coprocessor for data acquisition of the 6-channel displacement and current, the speed measurement of the gimbal servo system and high-speed rotor, the generating of the threelevel pulse width modulation (PWM) and the timing planning of the whole control system. Performance testing results are proved the validity of the proposed control system based on the MSCMG prototype system. Experiment results show that the maximum radial position error at the rotation speeds of 3000 rpm /min is less than 5% of the protection gap.
BibTeX:
@inproceedings{ISMB16_050,
  author = {Yang Zhang and Kun Liu and Jian Feng and Jingbo Wei and Zhizhou Zhang},
  title = {Design and Implementation of Control System Based on DSP and FPGA for Magnetically Suspended Control Moment Gyro},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_050.pdf}
}
2018 Sun, M., Zheng, S., Li, J. and Liu, Y. Design Method of Filter Cross Feedback Controller for Nutation Mode Suppression of AMBs-Rotors Proceedings of ISMB16  
Abstract: This paper explores a design method of the filter cross-feedback for nutation mode suppression of AMBs-rotor systems. The derivation of a multiple-input-multiple-output model (MIMO model) about AMBs-rotor was presented. Then the nutation stability of the system is analyzed by the complex coefficient method. Because the filter cross- feedback is an additive compensation, we can get the desired compensation by analyzing the Nyquist diagram of the system. At last, the filter cross-feedback controller is designed according to the compensation value. Simulation and experimental results demonstrate that the filter cross-feedback designed by the proposed method works well for restoring the stability of the system.
BibTeX:
@inproceedings{ISMB16_051,
  author = {Maolin Sun and Shiqiang Zheng and Jinlei Li and Yifan Liu},
  title = {Design Method of Filter Cross Feedback Controller for Nutation Mode Suppression of AMBs-Rotors},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_051.pdf}
}
2018 Zhao, W. and Jiang, K. Research on Fault Tolerant Operation of Multi-Winding Control Loop Failure in Active Magnetic Bearing System Proceedings of ISMB16  
Abstract: Active magnetic bearing system is a complex control system of electromechanical integration. Normal operation of active magnetic bearing system usually needs to drive all winding loops to work simultaneously. However, once one of the winding loops fails, the rotor suspension will run out of control and cause an accident. In order to improve the reliability of the whole operation of multi-winding loop, a method which implements the fault tolerant for the winding control loop is proposed. First, according to the distribution strategy of the same magnetic force produced by the minimum power consumption, the magnetic force of the fault winding will be redistributed to other normal windings to maintain the basic suspension state of the rotor, so as to win the time of the rotor speed reduction and eliminate or reduce the loss caused by uncontrolled suspension at high speed. All the failure modes that can achieve fault tolerant control are categorized. Each fault type only needs to solve one current distribution matrix. Then the fault tolerant control of different fault modes in a multiwinding loop can be achieved through coordinate transformation and winding remapping matrix. Finally, the experiments demonstrates the effectiveness of this fault tolerant method.
BibTeX:
@inproceedings{ISMB16_052,
  author = {WenJie Zhao and KeJian Jiang},
  title = {Research on Fault Tolerant Operation of Multi-Winding Control Loop Failure in Active Magnetic Bearing System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_052.pdf}
}
2018 Wang, P. and Zhu, C. H-inf Robust Differential Control for Electromagnetic Suspension Beam Proceedings of ISMB16  
Abstract: To stabilize the magnetic levitation beam, a robust control model is established and 𝑯H-inf robust controller is designed based on the hybrid sensitivity H-inf theory. Dynamic and state characteristics are analyzed using numerical simulation and experiment. The results show that the designed controller can realize the stable suspension, which further validates the effectiveness of the proposed approach.
BibTeX:
@inproceedings{ISMB16_053,
  author = {Peipei Wang and Changsheng Zhu},
  title = {H-inf Robust Differential Control for Electromagnetic Suspension Beam},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_053.pdf}
}
2018 Anantachaisilp, P. and Lin, Z. Fractional Order Control of Compressor Surge by Active Magnetic Bearings Proceedings of ISMB16  
Abstract: This paper demonstrates the design, analysis, and implementation of fractional order PID control (FOPID) for the control of compressor surge in a centrifugal compressor test rig by active magnetic bearings (AMBs). This is the first time that the FOPID controller is designed for and implemented on an AMB system for the surge control objective. In order to achieve the desired design specifications, the controller parameters are tuned by using evolutionary algorithms. Furthermore, a comparison of the performance and efficiency of the FOPID, PID, and an optimal controller is given based on simulation and experimental results.
BibTeX:
@inproceedings{ISMB16_054,
  author = {Parinya Anantachaisilp and Zongli Lin},
  title = {Fractional Order Control of Compressor Surge by Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_054.pdf}
}
2018 Hu, Z., Jiang, D., Han, X., Sun, H. and Qu, R. A Common-leg Power Electronics Converter for Multi-axis Active Magnetic Bearing Drive Proceedings of ISMB16  
Abstract: This paper has proposed a common-leg structure power electronics converter to drive the multi-axis active magnetic bearing(AMB) system. With this new structure, the number of devices is obviously reduced compared to existing topologies so that the cost can be decreased. Simulation and experiment are carried out to validate the feasibility of this converter. The results show that the current in either coil can be controlled independently and will not be influenced by the variation of other coil current. It also shows the performance of common-leg converter in the 4-DOF AMB system. The position of the rotor can be well controlled with this converter while the cost of the control system is greatly reduced.
BibTeX:
@inproceedings{ISMB16_055,
  author = {Zaidong Hu and Dong Jiang and Xun Han and Hongbo Sun and Ronghai Qu},
  title = {A Common-leg Power Electronics Converter for Multi-axis Active Magnetic Bearing Drive},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_055.pdf}
}
2018 Jiang, D., Li, T. and Han, X. A Fault-tolerant Drive System of Active Magnetic Bearing Proceedings of ISMB16  
Abstract: The non-contact magnetic bearings are widely used in high-speed rotating machinery. As the safety issue is one of the priorities of the whole system, in this paper, a fault-tolerant drive system is proposed. The proposed drive system with fullbridge converter architecture has two modes: the normal mode and the auxiliary mode. It can ride-through the open-circuit failure of power electronics devices in the drive and keep levitation. Failure of power electronics devices can be detected through the winding current in the magnetic bearing. Experimental results are provided in this paper to validate the failure detection and fault-tolerant control capability with levitation.
BibTeX:
@inproceedings{ISMB16_056,
  author = {Dong Jiang and Tian Li and Xun Han},
  title = {A Fault-tolerant Drive System of Active Magnetic Bearing},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_056.pdf}
}
2018 Ji, L., Zhou, J. and Wu, H. Vibration Mechanism Analysis of Magnetic Levitation Rotor System for Low Temperature Waste Heat Power Generation Proceedings of ISMB16  
Abstract: By using high speed maglev generator, the efficiency of low temperature waste heat generation system can be improved significantly. In this paper, the unbalanced magnetic pull (UMP) in the maglev generator, caused by dynamic and static eccentricity, is calculated theoretically and the analytical expression of the UMP is obtained based on Maxwell stress tensor method. Then, the vibration of a maglev rotor system is under the action of the UMP and the mass unbalance force is analyzed by the numerical method. Lastly, the effects of different eccentricities, torque angles and loads on the rotor vibration are discussed in detail. The conclusions for the maglev rigid rotor system are useful for the future research.
BibTeX:
@inproceedings{ISMB16_057,
  author = {Li Ji and Jin Zhou and HaiTong Wu},
  title = {Vibration Mechanism Analysis of Magnetic Levitation Rotor System for Low Temperature Waste Heat Power Generation},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_057.pdf}
}
2018 Verdeghem, J.V., Kluyskens, V. and Dehez, B. Comparison Criteria and Stability Analysis of Electrodynamic Thrust Bearings Proceedings of ISMB16  
Abstract: Electrodynamic bearings can ensure contactless levitation of rotors at room temperature solely relying on passive phenomena. Recently, two models describing the axial quasistatic and dynamic behaviours of a wide variety of electrodynamic thrust bearings (EDTBs) have been derived. However, although these models enable to study EDTB topologies in terms of stiffness and rotational losses, criteria allowing us to objectively compare their intrinsic qualities still lack. The present paper thus introduces four comparison criteria related to the axial stiffness, the bearing energy efficiency and the external damping required to stabilise the thrust bearing regardless of the spin speed. To this end, an analytical stability analysis is first performed on the basis of these dynamic models. This notably leads to static and dynamic conditions that ensure the stability at a specific speed. Finally, three topologies are compared on the basis of the comparison criteria in the framework of a case study.
BibTeX:
@inproceedings{ISMB16_058,
  author = {Joachim Van Verdeghem and Virginie Kluyskens and Bruno Dehez},
  title = {Comparison Criteria and Stability Analysis of Electrodynamic Thrust Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_058.pdf}
}
2018 Chen, J., Zhang, L., Luo, Y., Zhang, H. and Liu, J. Random Response Analysis of Magnetic Bearing Rotor System Proceedings of ISMB16  
Abstract: In the practical application, the magnetic bearingrotor system is subject to various external disturbances in practical application. Under certain control conditions, the random response characteristics of the magnetic bearing-rotor system is a particular concern. This paper analyzes the response characteristics of the magnetic bearing subjected to Gaussian random excitation in the horizontal direction. First, the magnetic bearing-rotor system model is deduced. Then, the random response of the rotor under Gaussian random excitation is derived. The probability of the collision of the rotor between the auxiliary bearing is calculated and the example is given. The paper conclusion provides a theoretical basis for the collision detection and prediction of the magnetic bearing-rotor system.
BibTeX:
@inproceedings{ISMB16_059,
  author = {Jinping Chen and Li Zhang and Yanyan Luo and Haining Zhang and Jun Liu},
  title = {Random Response Analysis of Magnetic Bearing Rotor System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_059.pdf}
}
2018 Liu, J., Chen, J., Zhang, H., Luo, Y. and Zhang, L. Study on Parametric Calculation of Magnetic Bearing Based on Modelica Proceedings of ISMB16  
Abstract: Magnetic bearing is a typically mechanical and electrical integration product, which is highly integrated technical representative of multi-disciplinary. It is leads to great difficulty in research and development. This complex device involves many fields and has the characteristics of complex structure and many parts. Based on the above , the modeling technology of the simulation system model plays an increasingly important role. In the field of magnetic bearing, the modelica is introduced to multidisciplinary and cross domain joint simulation modeling. It can achieve multidisciplinary integration under the unified modelica platform. This paper describes the characteristics and parameters modelica design and simulation of magnetic bearings based modelica. This research on the design and content of magnetic bearing based on modelica is for joint simulation of the whole system in the future.
BibTeX:
@inproceedings{ISMB16_060,
  author = {Jun Liu and Jinping Chen and Haining Zhang and Yanyan Luo and Li Zhang},
  title = {Study on Parametric Calculation of Magnetic Bearing Based on Modelica},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_060.pdf}
}
2018 Zhang, L., Ren, Y., Chen, J., Liu, J., Luo, Y. and Zhang, H. An Overview of the FMECA Technology of Magnetic Bearing System Proceedings of ISMB16  
Abstract: Active magnetic bearing is usually applied for the intelligent device that has high running speed and huge impact in the event of a failure. It has become the research hotspot of monitoring and diagnosis technology in the field of intelligent machine. Intelligent magnetic bearing system understand the inherent state by itself, and through fault diagnosis, prediction, health management to continuously optimize and adjust itself. It is necessary to deeply study the failure mechanism of magnetic bearing system, which is helpful to develop the intelligent machine. this article mainly expounds the observed index characteristics and fault modes. Failure modes and effects criticality analysis (FMECA) is introduced to design the magnetic bearing system. The FMECA design process is to extract fault features of the best indicators or conditions, early detect and isolate faults, and predict the remaining life of the key components, finally realize the lower maintenance cost, higher safety and reliability.
BibTeX:
@inproceedings{ISMB16_061,
  author = {Li Zhang and Yafeng Ren and Jinping Chen and Jun Liu and Yanyan Luo and Haining Zhang},
  title = {An Overview of the FMECA Technology of Magnetic Bearing System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_061.pdf}
}
2018 Wimmer, D., Hutterer, M., Hofer, M. and Schroedl, M. Variable Space Vector Modulation for Self-Sensing Magnetic Bearings Proceedings of ISMB16  
Abstract: The subject of this paper is an improvement of a selfsensing control of a three-phase radial magnetic bearing based on the so called INFORM method. The focus of this paper lies on a modification of the space vector modulation to achieve a high position resolution as well as a high actuator dynamic at low DClink voltage levels. Therefore, certain constraints for the space vector modulation must be fulfilled to allow a self-sensing operation of the bearing. For this reason, different kinds of space vector modulations are designed theoretically as well as proven in experiments on a prototype of a radial magnetic bearing. Finally, the obtained performance of the INFORM method is shown by a linearity measurement and a comparison of the small signal behavior by means of external position sensors.
BibTeX:
@inproceedings{ISMB16_062,
  author = {Dominik Wimmer and Markus Hutterer and Matthias Hofer and Manfred Schroedl},
  title = {Variable Space Vector Modulation for Self-Sensing Magnetic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_062.pdf}
}
2018 Gao, T.-y., Zhou, J. and Jin, C.-w. Rotor Loss Optimization and Comprehensive Analysis of High-speed Magnetic Levitation Turbine Generator Proceedings of ISMB16  
Abstract: The high speed magnetic levitation turbine generator used in Organic Rankine cycle (ORC) system will produce wind friction loss due to the high density of work environment and high eddy current loss in the part of permanent magnet (PM) rotor, which obviously effect the performance and stability of PM. In order to minimize the loss of PM rotor, this paper presented a comprehensive optimization design for the stator and rotor structure of turbine-generator. Firstly, the physical performances coupled with design variables, such as loss, generator power, rotor dynamic, strength and axial force of AMB were analyzed, mainly analyzed the structural variables coupled with design variables due to the effects of single constraint and the decoupling methods, which eliminated irrelevant variables in the final optimization. Neural network was used to establish agent models for each physical performance and brought into comprehensive optimization process of total PM rotor, which greatly improved the efficiency of optimization. The result of optimization is that the total rotor loss decreased 28% and all of other physical performance meet the requirements.
BibTeX:
@inproceedings{ISMB16_063,
  author = {Tian-yu Gao and Jin Zhou and Chao-wu Jin},
  title = {Rotor Loss Optimization and Comprehensive Analysis of High-speed Magnetic Levitation Turbine Generator},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_063.pdf}
}
2018 Tshizubu, C. and Santisteban, J.A. A Study about Turning Three-Phase Electrical Motors in Active Magnetic Bearings Proceedings of ISMB16  
Abstract: Nowadays, the operation principle of active magnetic bearings (AMB’s) is well known and their industrialization can be considered mature. Nevertheless, spreading this technology around all the world is yet a tough work as its actual production cost is even high. Taking an operative rotational machine, by instance, in the process of a substitution of mechanical bearings by magnetic ones, as the mechanical details are customized, the stator construction cost can be quite expensive. In this sense, in order to save time and reduce costs, an alternative approach has been studied. This consists on turning conventional AC electrical motors in AMB’s. Different from a previous reported work, where a twophase induction motor was modified and experimentally tested, in this work, a three-phase induction motor is studied through Finite Elements Analysis. Its distributed windings structure is unchanged while the rotor is substituted by another one without a squirrel cage. To simulate the AMB behavior, two conditions were evaluated: first, two phase windings were supplied, while the third one was kept open, and second, all the three phase windings were supplied. Finally, the equivalent net forces were evaluated as a function of differential control currents, holding the rotor centralized, and also as a function of the radial displacements, holding all the windings currents constant. Simulation results show that supplying the three windings is desirable from the point of view of the radial displacement control.
BibTeX:
@inproceedings{ISMB16_064,
  author = {Christian Tshizubu and Jose Andres Santisteban},
  title = {A Study about Turning Three-Phase Electrical Motors in Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_064.pdf}
}
2018 Hofer, M., Wimmer, D. and Schroedl, M. Analysis of a Current Biased Eight Pole Radial Active Magnetic Bearing Regarding Self-Sensing Proceedings of ISMB16  
Abstract: In this work a current biased radial active magnetic bearing is investigated with regard to a possible self-sensing operation. The bearing is designed by the help of finite element methods. The force characteristic is investigated and bearing parameters are identified by simulation. Additionally, the position dependency of the coil inductances is evaluated which is the basis for self-sensing. The fundamental principle of the rotor position determination based on current slopes by using the differential open loop transformers approach is presented. Further, simulations are performed to analyze AMB current signals with regard to the rotor position. Finally, experimental tests with an AMB prototype are shown to verify the theoretical analysis. The measured rotor position at constant eccentricity confirms the functionality and represents the starting point for a future implementation of the self-sensing control to the prototype and detailed analysis of the self-sensing performance.
BibTeX:
@inproceedings{ISMB16_065,
  author = {Matthias Hofer and Dominik Wimmer and Manfred Schroedl},
  title = {Analysis of a Current Biased Eight Pole Radial Active Magnetic Bearing Regarding Self-Sensing},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_065.pdf}
}
2018 Yao, Y., Ma, Y., Su, Y. and Yu, S. Factors Influencing the Vibrations of a Magnetically Suspended Pump Proceedings of ISMB16  
Abstract: Vibrations are a common problem in pumps that reduce the pump efficiency, cause excessive noise, and can even induce fatigue failures. Active magnetic bearings (AMBs) have been extensively investigated to reduce vibrations. Most research has focused on control methods to reduce the vibrations, but the mechanical characteristics of the bearing are also important for vibration isolation since they are the main vibration transfer path. A finite element model of a 30 kW pump prototype suspended on 5-DOF AMBs was used to analyze the pump vibrations with the AMBs simplified to spring-dampers with equivalent stiffness and the damping related to the rotational speed. Two external excitations were analyzed with an unbalanced centrifugal force acting on the rotor in one case and the other case having a hydrodynamic force acting on the impeller. The model was simplified to improve the simulation efficiency by using a time dependent hydrodynamic force obtained from a CFD model that was assumed to not be affected by the system parameter changes. The model was then used to investigate the effects of several key structural parameters on the magnetic pump vibrations, including the motor shell thickness, the junction box position, the stiffness and damping of the magnetic bearing and the isolator as well as the mounting method. Then, the results were used to design a new pump with FE simulations used to judge the effectiveness of the design. The simulations show that the design effectively suppresses the vibrations at the working speed. This research provides a method for designing pumps with less vibrations.
BibTeX:
@inproceedings{ISMB16_066,
  author = {Yichen Yao and Yanhui Ma and Yixin Su and Suyuan Yu},
  title = {Factors Influencing the Vibrations of a Magnetically Suspended Pump},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_066.pdf}
}
2018 Chen, C.-Y., Liu, C.-C., Yuliane, A. and Kuan, Y.-D. Rotor Dynamic Analysis in Power Lost Condition for Maglev High-speed Fluid Machinery Proceedings of ISMB16  
Abstract: The advantages offered by active magnetic bearings make that bearing widely used in high-speed Fluid Machinery, the applications that use active magnetic bearing must be equipped with touchdown (auxiliary) bearing system to prevent the damages of impellers and motor in case of a system failure. When the drop event occurs, active magnetic bearing cannot support the rotor stably, touchdown bearings will be a backup for active magnetic bearings to support the rotor during drop down event. Therefore, the properly designed touchdown bearing system is necessary to protect the active magnetic bearings assembly and other critical machine components from direct contact with the rotor during in a loss of AMB power events. This study has based on the un-lubricated Hertzian contact model to analyze the rotor drop dynamics, and the Finite Element method is used to create the flexible rotor model. Finally, the simulation results of this study will show the rotor orbit, rotor response and contact force under rotor drop events by using MATLAB software.
BibTeX:
@inproceedings{ISMB16_067,
  author = {Chao-Yun Chen and Chung-Che Liu and Aindri Yuliane and Yean-Der Kuan},
  title = {Rotor Dynamic Analysis in Power Lost Condition for Maglev High-speed Fluid Machinery},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_067.pdf}
}
2018 Ma, Y., Su, Y., Yao, Y. and Yu, S. Dynamic Simulation of Maglev Water Pump on A Moving Base by Using Multibody Dynamics Method Proceedings of ISMB16  
Abstract: As one of the key components of a rotating machinery, the bearing has a significant effect on the dynamic response of the system. Compared with traditional mechanical bearings, the magnetic bearing has many advantages such as no contact and friction, no need of lubrication, no wear, low noise, high rotational speed, etc. Therefore, the magnetic bearing is an ideal support for rotating machinery, i.e. a maglev water pump. During the modeling and simulation the magnetic bearing, it is usually simplified as a spring-dampers with equivalent stiffness and damping, which ignore the dynamic characteristics of the magnetic bearing. Besides, the study of simulation mainly focuses on the vibration reduction of the rotor or the vibration transfer to the base, while little was known about the dynamic response of the maglev machinery system on a moving base. In this paper, a time-domain rigid-flexible coupling simulation model of a maglev water pump on a moving base is established by using multibody dynamics method. In this model, the flexible rotor is simplified as several discrete rigid parts connected with massless beam force and the control system of the magnetic bearing with PID controller is realized by utilizing state space equations. Then the dynamic response of the maglev water pump on a pitching and rolling base was obtained based on the established model.
BibTeX:
@inproceedings{ISMB16_068,
  author = {Yanhui Ma and Yixin Su and Yichen Yao and Suyuan Yu},
  title = {Dynamic Simulation of Maglev Water Pump on A Moving Base by Using Multibody Dynamics Method},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_068.pdf}
}
2018 Lyu, M., Liu, T., Li, Z., Wang, Z., Wang, Y. and Kotnikova, M. Instantaneous frequency extraction of full rub in touchdowns of AMBs based on polynomial chriplet transform Proceedings of ISMB16  
Abstract: In this paper, polynomial chriplet transform (PCT) is introduced to extract the time-frequency characteristics of the rotor orbit during full rub in active magnetic bearings (AMB). In order to analyze the advantages and disadvantages of different time-frequency methods in the analysis of time-frequency characteristics of the signal, the short-time Fourier transform (STFT), Wigner-Ville distribution, general linear chirplet transform (GLCT) and PCT have been used to process the sample signal. Comparison between the four methods have been made and it is found that PCT has the highest accuracy in extracting the instantaneous frequency (IF) of the signal. Finally, PCT has been used to extract the IF during full rub in touchdowns of AMBs.
BibTeX:
@inproceedings{ISMB16_069,
  author = {Mindong Lyu and Tao Liu and Zilin Li and Zixi Wang and Yuming Wang and Margarita Kotnikova},
  title = {Instantaneous frequency extraction of full rub in touchdowns of AMBs based on polynomial chriplet transform},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_069.pdf}
}
2018 Vasco, V., Gomes, A.N., David, D. and Santisteban, J. Considerations on the Mechanical Dynamics of Interconnected Flux Three-Pole Magnetic Bearings Proceedings of ISMB16  
Abstract: This work presents a step-by-step procedure on how to get the reluctance forces in the optimal three-pole magnetic bearing. These forces are analyzed near the equilibrium point, where linearization produces satisfactory results. Besides that, a linear dynamical system is proposed based on the operation under four types of disturbances, shaft with constant angular speed and small displacements over the center.
BibTeX:
@inproceedings{ISMB16_070,
  author = {V.R. Vasco and A.C.Del Nero Gomes and D.F.B. David and J.A. Santisteban},
  title = {Considerations on the Mechanical Dynamics of Interconnected Flux Three-Pole Magnetic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_070.pdf}
}
2018 You, S.J. and Ahn, H.-J. Position Estimation for Self-sensing Magnetic Bearings using Artificial Neural Network Proceedings of ISMB16  
Abstract: Although signal injection, state observer and parameter estimation methods were previously studied for selfsensing AMBs, variety of nonlinear effects such as eddy current, magnetic saturation and coil flux leakage make it difficult to apply for industrial applications. In this paper, we study a position estimation for self-sensing active magnetic bearings (AMBs) using artificial neural network (ANN), especially RNN method. Mathematical model of self-sensing AMBS are introduced including PWM duty, average current, current ripple and current slope, and various nonlinear effects are investigated quantitatively. We applied ANN method to deal with the non-linear effects of self-sensing AMBs. Finally, selfsensing AMBs using ANN are simulated by MATLAB Simulink its performances are compared with previous self-sensing methods.
BibTeX:
@inproceedings{ISMB16_071,
  author = {Seong Jong You and Hyeong-Joon Ahn},
  title = {Position Estimation for Self-sensing Magnetic Bearings using Artificial Neural Network},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_071.pdf}
}
2018 Ahn, H.-J. Stability Margin Evaluation of AMB Rotor Systems Using Singular Value Decomposition Proceedings of ISMB16  
Abstract: Active magnetic bearings (AMBs) are a proven technology that has been used in numerous rotating machines and is primarily being applied to many new turbomachines. Therefore, proper evaluation of rotordynamic performances is very important for OEM and end-users of AMBs. API 617 requires unbalance response limit and separation margin while ISO 14839-3 checks stability margin using measured sensitivity. In addition, singular value decomposition is mathematical tool used extensively in control community and can be used to analyze problems of rotating machines such as unbalance response, model reduction and stability margin. This paper presents stability margin evaluation of AMB rotor systems using singular value decomposition (SVD). First, Two AMB rotor systems and their frequency measurement are introduced. Then, we review linear control theory related to stability and performance evaluation using SVD. Identifications of two AMB rotor systems are performed and exact stability margins of two AMB rotor systems are analyzed based on linear control theory and SVD. Finally, stability margin evaluation of linear control theory and ISO 14839-3 are compared.
BibTeX:
@inproceedings{ISMB16_072,
  author = {Hyeong-Joon Ahn},
  title = {Stability Margin Evaluation of AMB Rotor Systems Using Singular Value Decomposition},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_072.pdf}
}
2018 Su, Y., Yao, Y., Ma, Y., Li, H., Yu, W. and Yu, S. Dynamic and Control Simulation of Rotor Suspended by Three Radial AMBs Based on Multibody Dynamics Proceedings of ISMB16  
Abstract: Multiple AMBs have greater bearing capacities than two radial AMBs but the multiple AMBs affect the system dynamics and control characteristics. The dynamic equations were developed for a three radial AMB system to calculate the critical speed and the unbalanced response of the three radial AMB system which are compared with those of a two AMB system. The model accounts for bearing misalignment and the effect of different support locations. The model is a flexible rotor with discs including a rigid body and Euler-Bernoulli beam based on an absolute nodal coordinate formulation and constraints based on the first type of Lagrange equation. The electromagnetic force on the AMB at each DOF is controlled by a PID control law in real time. The governing equations including the constraint equations are solved by the available differential algebraic equation solver.
BibTeX:
@inproceedings{ISMB16_073,
  author = {Yixin Su and Yichen Yao and Yanhui Ma and Hongwei Li and Wentao Yu and Suyuan Yu},
  title = {Dynamic and Control Simulation of Rotor Suspended by Three Radial AMBs Based on Multibody Dynamics},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_073.pdf}
}
2018 Diaz, D., Pinto, F., Ritto, T., Maldonado, D. and Côrtes, V. Nonparametric Identification of a Small AMB Test Rig at Several Rotating Speeds Proceedings of ISMB16  
Abstract: In this paper a comparison of experimental frequency response functions (FRFs) obtained in a small-scale Active Magnetic Bearing (AMB) test rig at several rotating speeds is made, in order to assess the gyroscopic and shaft unbalances effects in practical identification procedures. The excitation frequencies used in this work were established below the critical speed (rigid rotor behavior) and a broadband signal is used as excitation input.
BibTeX:
@inproceedings{ISMB16_074,
  author = {Diego Diaz and Fernando Pinto and Thiago Ritto and David Maldonado and Vinicius Côrtes},
  title = {Nonparametric Identification of a Small AMB Test Rig at Several Rotating Speeds},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_074.pdf}
}
2018 Hu, Y., Guo, W., He, Y., Hu, D. and Li, X. Design and Application for Power Amplifier of Magnetic Bearing Proceedings of ISMB16  
Abstract: Power Amplifier is a crucial part in the magnetic bearing control system, so the performance of power amplifier plays an important role in the magnetic bearing control system. According to the 5-DOF active magnetic bearing system, the half bridge structure which needs twenty power parts in total is generally used, with a bulky bearing controller. so this kind of power amplifier cannot be appropriate for the magnetic compressor who has a strict installation size require。A novel kind of power amplifier is proposed which is based on the common lower bridge structure, with the ability of decreasing the amount of the power parts to 15 and cutting down the volume of bearing controller. The simulation and test shows that the common lower bridge has a good response of capability and actual performance.
BibTeX:
@inproceedings{ISMB16_075,
  author = {Yusheng Hu and Weilin Guo and Yongling He and Daofu Hu and Xue Li},
  title = {Design and Application for Power Amplifier of Magnetic Bearing},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_075.pdf}
}
2018 Cui, Q., Tonoli, A., Amati, N., Bonfitto, A. and Molina, L.M.C. Damping Strategies on a Horizontal Rotor Supported by Electrodynamic Bearings Proceedings of ISMB16  
Abstract: Electrodynamic Bearings (EDBs) exploit Lorentz type of magnetic force due to the eddy currents induced in a rotating conductor, which has relative motion in a magnetic field, to levitate the rotor. The character of passive levitation without negative stiffness that can be realized using permanent magnets in room temperature with relatively simple configuration makes EDBs an appealing alternative to Active Magnetic Bearings (AMBs). However, the instability of rotors supported by EDBs is the key issue that prevents the application of EDBs. In this paper, the damping strategies for EDB systems are investigated using additional AMBs implemented. The hybrid bearing system has been built to stabilize EDB system using damping from AMBs which work as Active Magnetic Dampers (AMDs). It can be further exploited to investigate the damping strategies with active control of the AMBs. The results are presented in this paper showing different possible solutions of EDB stabilization.
BibTeX:
@inproceedings{ISMB16_076,
  author = {Qingwen Cui and Andrea Tonoli and Nicola Amati and Angelo Bonfitto and Luis Miguel Castellanos Molina},
  title = {Damping Strategies on a Horizontal Rotor Supported by Electrodynamic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_076.pdf}
}
2018 Zhang, X., Sun, Z., Fan, T., Zhao, L., Yan, X., Zhao, J. and Shi, Z. A Review on Hysteresis in Magnetic Bearing-Rotor System Proceedings of ISMB16  
Abstract: There are inevitably hysteresis phenomena in magnetic bearing-rotor systems. On the one hand, the nonlinear relationship of the restoring force and deformation of the engineering materials, especially composites and internal friction between the rotor components may result in hysteresis. On the other hand, there is inherently magnetic hysteresis in the actuator. The hysteresis is a typical one of nonlinear characteristics. The property may have a strong effect on the stability of systems, and make system exhibit complex, unpredictable nonlinear behaviors. It is crucial to analyze magnetic bearing-rotor system by taking account of hysteresis. In this paper, the literature about the magnetic bearing-rotor system with hysteresis are reviewed. The characteristics of nonlinear systems with hysteresis and the effects of hysteresis on systems' dynamics are summarized. The modeling approaches are researched and the advantages and disadvantages of each method are pointed out. This paper introduces various methods applied to nonlinear systems with hysteresis and illustrates corresponding results. The methods which could be appropriate for magnetic bearing-rotor systems subjected to hysteresis are discussed and the future research directions have been prospected.
BibTeX:
@inproceedings{ISMB16_077,
  author = {Xiaoshen Zhang and Zhe Sun and Tianpeng Fan and Lei Zhao and Xunshi Yan and Jingjing Zhao and Zhengang Shi},
  title = {A Review on Hysteresis in Magnetic Bearing-Rotor System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_077.pdf}
}
2018 Ovchinnikov, V., Nikolaev, M. and Litvinov, V. The Model of Dynamics of Multispan Flexible Rotor on Active Magnetic Bearings Applied for Diagnostics Proceedings of ISMB16  
Abstract: The paper presents a model of dynamics of multispan flexible rotor on active magnetic bearings (AMB) applied for composing of diagnostic characters of malfunctions.
BibTeX:
@inproceedings{ISMB16_078,
  author = {Viktor Ovchinnikov and Mikhail Nikolaev and Vasily Litvinov},
  title = {The Model of Dynamics of Multispan Flexible Rotor on Active Magnetic Bearings Applied for Diagnostics},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_078.pdf}
}
2018 Huang, C., Dai, C. and Luo, G. Study on Signal Processing Technology of Relative Position Detection Sensor for High Speed Maglev Train Proceedings of ISMB16  
Abstract: Relative position detection sensor is critical component for High Speed Maglev Train (HSMT) as they provide direction, speed, tooth-slot count and phase angle for traction system which drives maglev train. The traction system has higher requirements on the accuracy and stability of the phase angle signal. The demodulated wave signal directly affects the precision of the phase. In order to obtain higher accuracy of the demodulation signal, a demodulation approach based on an analog switch is proposed. The difference between early and present signal generating circuit is compared. Then the proposed demodulation method is analyzed mathematically. Moreover, the comparison between demodulation of the early sensor based on the analog multiplier and that based on the analog switch is implemented. A series of tests have been adopted to validate the performance of the proposed demodulation method and show that a more stable and accurate demodulation signal can be obtained.
BibTeX:
@inproceedings{ISMB16_079,
  author = {Cuicui Huang and Chunhui Dai and Guibin Luo},
  title = {Study on Signal Processing Technology of Relative Position Detection Sensor for High Speed Maglev Train},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_079.pdf}
}
2018 Sahinkaya, A. and Sawicki, J.T. System Identification of AMB Systems: Step Towards Automated Commissioning Proceedings of ISMB16  
Abstract: Active magnetic bearings (AMBs) are mechatronic devices that provide contact-free support to rotors via electromagnetic forces. An accurate model of the system is necessary to design and evaluate controllers for reliable operation. In this paper, identification of AMB systems is studied with the aim of reducing user involvement in the model identification process. The assumed a priori information consists of the amplifier model, dynamics of AMB electronics, and time delays due to AD/DA conversions, which are relatively easy to identify compared to the rotor model and AMB force model. It is also assumed that there exists a predesigned controller that stabilizes the system, not necessarily a performant one, in order to conduct system identification experiments. To obtain frequency response data for identification purposes, three common excitation signals for rotor systems are considered: impulse signal, PRBS (Pseudo-Random Binary Sequence) signal, and stepped sine signal. Feasibility of using each signal along with advantages and disadvantages over each other in obtaining accurate data in the context of commissioning is discussed. The identification problem is cast as a nonlinear least square (NLS) optimization problem using a parametrized model of an AMB system. The resulting model is physically interpretable, which allows defining uncertainties for AMB force constants and flexible mode frequencies that are standard for the model-based controller design strategies. The presented identification procedure is applied to an experimental AMB rotor system to validate the approach. A signal-based H∞ controller is designed based on the identified model to show the applicability of the presented method for commissioning of AMB systems. Performance of the system with H∞ controller is compared to an experimentally-tuned PID controller to demonstrate the superiority of a model-based controller, hence the importance of having an accurate plant model.
BibTeX:
@inproceedings{ISMB16_080,
  author = {Alican Sahinkaya and Jerzy T. Sawicki},
  title = {System Identification of AMB Systems: Step Towards Automated Commissioning},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_080.pdf}
}
2018 Zhang, Y., Xue, B., Gu, T. and Liu, S. Research on Coupling Property of Vertical and Transverse Force of Maglev Platform Proceedings of ISMB16  
Abstract: Maglev platform is a support platform which has special advantages, such as no contact, no lubrication, easy maintenance, long service life and high precision. It has a very broad application prospects. In the research of maglev platform, the design and optimization of electromagnets is critical. In this paper, the overall structure of the maglev platform and electromagnets has been introduced firstly. According to the technical requirements with large span and big air gap, the parameters of iron cores and coils are given for the following calculation and simulation. Secondly, in order to study the property of vertical and transverse force produced by the electromagnets of maglev platform, the calculation based on magnetic circuit method of the bearing force of toroidal and U-type electromagnets are carried out. Mathematical analytical model of vertical and transverse magnetic force was deduced by using virtual displacement method. The vertical and transverse magnetic force dependence on vertical gap and transverse displacement was analyzed. Coupling between vertical and transverse magnetic force was studied. The forces was simulated by finite-element method and the simulation results were compared with the calculated results. Theoretical results for designing vertical and transverse decoupling control system were provided. Lastly, the bearing capacity, magnetic field distribution and magnetic induction intensity of the simulation model, which is established based on previous parameters, are analyzed through Ansoft finite element method. Combining with smoothing and trimming, defects of the electromagnets are improved. The result of analysis on the characteristics of the electromagnets is helpful to improve the control precision and stability of the platform, and the study of the issue involved has very high theory value and realistic significance.
BibTeX:
@inproceedings{ISMB16_081,
  author = {Yuzhe Zhang and Bowen Xue and Ting Gu and Shuqin Liu},
  title = {Research on Coupling Property of Vertical and Transverse Force of Maglev Platform},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_081.pdf}
}
2018 Xiong, Z., Hu, Y., Wu, H., Lin, Z. and Li, M. Design and Analysis of Maglev Support System for Vacuum Tube Maglev Transportation Proceedings of ISMB16  
Abstract: Vacuum Tube Maglev Transportation significantly reduces the air resistance and eliminates the effects of mechanical friction. With its speed, low energy consumption and other advantages have attracted much attention. The structure and characteristics of its magnetic suspension support are one of the hot research issues. In this paper, an EDS&EMS hybrid support is used. The permanent magnet electrodynamic suspension provides the main levitation and guidance force, and the electromagnetic suspension is used to improve the stability of the support. The physical and simulation models of the support structure are established. Through analysis and simulation, the influence of bearing capacity on air gap and velocity is studied. The results of the two methods are basically consistent. Magnetic field distribution was analyzed in 2D static and transient magnetic fields by ANSYS Maxwell. The causes and trends of errors in analytical methods and simulations are analyzed, which provided a certain foundation for the study of vacuum tube maglev transportation.
BibTeX:
@inproceedings{ISMB16_082,
  author = {Zhenyu Xiong and Yefa Hu and Huachun Wu and ZiHao Lin and Ming Li},
  title = {Design and Analysis of Maglev Support System for Vacuum Tube Maglev Transportation},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_082.pdf}
}
2018 Javed, A., Mizuno, T., Takasaki, M., Ishino, Y. and Yamaguchi, D. Variable Stiffness Approach to Reduce Vibration Induced in Passively-supported Directions of an Active Magnetic Suspension System Proceedings of ISMB16  
Abstract: This study focuses on the vibration reduction in lateral directions by varying the stiffness of the system in a vertically active magnetic suspension system. Vibration can easily be induced in the lateral directions while the normal directions are actively controlled with a pair of electromagnets working in a differential driving mode. Switching stiffness control is applied to such a system to reduce the lateral vibration of a floator that is a 25 mm ferromagnetic ball. The normal position of the floator is unchanged even if the stiffness control is applied to the system. The efficacy of the control is evaluated by several experiments which show the reduction of lateral vibrations.
BibTeX:
@inproceedings{ISMB16_083,
  author = {Asief Javed and Takeshi Mizuno and Masaya Takasaki and Yuji Ishino and Daisuke Yamaguchi},
  title = {Variable Stiffness Approach to Reduce Vibration Induced in Passively-supported Directions of an Active Magnetic Suspension System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_083.pdf}
}
2018 Hu, Y., Zhang, F., Zhang, X., Gong, G., Su, J. and Zhang, C. Rotor Dynamic Analysis on the Bearing-rotor System of Magnetic Centrifugal Compressor Proceedings of ISMB16  
Abstract: Modal frequency and modal vibration mode of a centrifugal compressor rotor-bearing system, which equipped with magnetic bearings, are significant target parameters to insure stable operation of the compressor. Meanwhile, calculations and optimizations of those parameters are also necessary processes of compressor structure designing. In this paper, basing on the basic theories of rotor dynamics, ANSYS is used to analyze vibration mode and modal frequency of a compressor rotor-bearing system. The correction coefficient of modulus of elasticity of laminated and basic excitation sources caused by impellers in pneumatic section and magnetic bearings’ stiffness parameters are considered when doing rotor dynamics modeling simultaneously throughout the simulation. Influences on critical speed of the rotor-bearing system caused by rotor speed is analyzed through the simulation. It has provided a reference to designing shafts in long axis system of magnetic high-speed centrifugal compressor by obtaining the simulation results.
BibTeX:
@inproceedings{ISMB16_084,
  author = {Yusheng Hu and Fang Zhang and Xiaobo Zhang and Gao Gong and Jiuzhang Su and Chao Zhang},
  title = {Rotor Dynamic Analysis on the Bearing-rotor System of Magnetic Centrifugal Compressor},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_084.pdf}
}
2018 Hu, Y., Geng, J., Huang, W. and Wang, T. Research on Eddy Current Field Characteristics of Eddy Current Displacement Sensor Based on ANSOFT Proceedings of ISMB16  
Abstract: The eddy current field characteristics of the probe based on the eddy current magnetic field sensing principle of eddy current displacement sensor are the key to influence the performance of the sensor. In this paper, the eddy current field simulation of probe coils with different structures is performed. The effect of coil size and shape on the performance of the sensor is analyzed. The eddy current field characteristics of probe coils with different structures are studied. And build an experimental platform to test and analyze, verify the correctness of the simulation results, and lay the foundation for perfecting the eddy current displacement sensor theory and further optimization design.
BibTeX:
@inproceedings{ISMB16_085,
  author = {Yusheng Hu and Jiqing Geng and Weicai Huang and Tuo Wang},
  title = {Research on Eddy Current Field Characteristics of Eddy Current Displacement Sensor Based on ANSOFT},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_085.pdf}
}
2018 Cao, G.-Z., Guo, J.-C., Huang, S.-D. and Li, W.-B. Modeling of Levitation Force for a Wireless-Moving-Levitating Light with Multiple Magnetic Fields Proceedings of ISMB16  
Abstract: This paper presents the modeling of the levitation force for a wireless-moving-levitating light (WMLL) developed in the laboratory. The mechanical structure of the WMLL is first given. A control scheme, which is used to regulate the energized current for stable, quick, and accurate levitation of the levitating disk, is then presented. Furthermore, the model of the levitation force is theoretically derived based on the Ampere molecular current hypothesis and the Biot-Savart law. Additionally, a finite element analysis is performed to characterize the levitation force. Finally, the effectiveness of the model is verified through the experimental results.
BibTeX:
@inproceedings{ISMB16_086,
  author = {Guang-Zhong Cao and Jin-Chang Guo and Su-Dan Huang and Wen-Bo Li},
  title = {Modeling of Levitation Force for a Wireless-Moving-Levitating Light with Multiple Magnetic Fields},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_086.pdf}
}
2018 Mitterhofer, H., Rakov, M. and Gruber, W. Sum-flux Rotor Position Sensor with Self-balancing Magnetic Bearing Concept Proceedings of ISMB16  
Abstract: Rotor position sensing is a key feature for successful operation for magnetic bearings. A position sensing concept based on the induction principle, embedded in a symmetrical multi-phase system may provide many interesting features. The knowledge of the electrical system’s phase angle, combined with a conductive sensing coil as the only additional physical component, the principle allows detecting the radial rotor offset and can be used for providing self-balancing magnetic bearing functionality. The paper is aimed at clearly demonstrating the concept and is not meant as an actual magnetic bearing design.
BibTeX:
@inproceedings{ISMB16_087,
  author = {Hubert Mitterhofer and Mikhail Rakov and Wolfgang Gruber},
  title = {Sum-flux Rotor Position Sensor with Self-balancing Magnetic Bearing Concept},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_087.pdf}
}
2018 Wang, D., Wang, N., Chen, K., Ye, C., Ran, S., Wu, H. and chunsheng Song Unbalance Response of a Magnetically Suspended Dual-rotor System Proceedings of ISMB16  
Abstract: The magnetic suspended dual-rotor system (MSDS) applied in more electric aero-engine can eliminate the wear and lubrication system of mechanical bearings and solve the vibration control issue of system effectively, which provides the possibility to improve the performance of aero-engine significantly. This research focuses on the unbalance response of the MSDS. First, a structure of dual-rotor system supported by two active magnetic bearings (AMBs) and two permanent magnetic bearings (PMBs) is proposed. With classic PD control adopted, the bearing characteristics of AMBs are modeled as the equivalent stiffness and equivalent damping, and the PMBs are modeled as elastic support with stiffness. Then, the Riccati transfer matrix method with good numerical stability is used to establish the unbalance response model of the MSDS. Next, the interaction between inner and outer rotors is analyzed with single rotor imbalance excitation, and the unbalance response of the MSDS is investigated with dual-rotor imbalance excitation. In addition, a simple and effective approach to avoid simultaneous excitations by both inner and outer rotors is pointed out. Finally, experiments on the unbalance response of a magnetic suspended single-rotor system is conducted to validate some theoretical analysis of the MSDS.
BibTeX:
@inproceedings{ISMB16_088,
  author = {Dongxiong Wang and Nianxian Wang and Kuisheng Chen and Chun Ye and Shaolin Ran and Huachun Wu and chunsheng Song},
  title = {Unbalance Response of a Magnetically Suspended Dual-rotor System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_088.pdf}
}
2018 Yu, J., Zhao, L., Zhang, K., Liu, P., Li, Y. and Pu, P. Stability Analysis and Testing of the High-Speed Active Magnetic Bearing-Flywheel System in the Rotating Frame Proceedings of ISMB16  
Abstract: The active magnetic bearing (AMB) can greatly improve the stability of the flywheel system and increase the maximum flywheel speed. However, if the frame of active magnetic bearing-flywheel system (AMB-FS) rotates in the different direction from the flywheel, the strong gyroscopic effect of high-speed flywheel will greatly affect the system stability. In this study, to realize the high stability of the AMB-FS at ultra-high flywheel speed with low power consumption, the main purpose and content are implementing active control to the strong gyroscopic effect caused by the rotating frame and suppressing the precession and nutation of the flywheel. Through the stability analysis, AMB controller design, simulation and dynamic experiment, the AMB-FS is designed and studied, and the system stability is analyzed in the experiment. In the experiment, the gyroscopic effect of the flywheel is effectively suppressed. In the vacuum environment, the flywheel can be suspended stably at any speed within the range of 0 to 30000rpm, and the AMB-FS has the power consumption of 17.82W and needs no cooling measures The flywheel speed could exceed 𝟑31200rpm and still possess the speeding potential. The ultimate performance test shows that the maximum frame rotational speed can reach 3.5deg/s at the rated flywheel speed of 30000rpm, and the AMB-FS shows high stability.
BibTeX:
@inproceedings{ISMB16_089,
  author = {Jinpeng Yu and Lei Zhao and Kai Zhang and Pingfan Liu and Yanbao Li and Pengcheng Pu},
  title = {Stability Analysis and Testing of the High-Speed Active Magnetic Bearing-Flywheel System in the Rotating Frame},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_089.pdf}
}
2018 Li, H., Tian, J., Su, Y., Yu, W. and Yu, S. The Motion of the Rotor Acrossing Critical Speed Levitated by AMBs with Anisotropic Stiffness Proceedings of ISMB16  
Abstract: The stiffness and damping ratios in x and y radial degrees of freedom (DOF) of active magnetic bearing (AMB) may be different due to the machining and assembly errors. Therefore, the critical speeds in the two radial DOFs will not be equal. To study the rotor motion when its speed is between the two unequal radial critical speeds, a model of a rigid Jeffcott rotor levitated by AMBs with anisotropic bearing stiffness and damping ratio was built in this paper. The differential equation of motion of the model was derived from Lagrange equation firstly. Then the motion of the rotor geometric center was given. Through plotting the orbit of the rotor geometric center, it is found that the backward whirling movement of the rotor can be observed when the product of the damping ratios in x and y DOFs is lower than a critical value.
BibTeX:
@inproceedings{ISMB16_090,
  author = {Hongwei Li and Jing Tian and Yixin Su and Wentao Yu and Suyuan Yu},
  title = {The Motion of the Rotor Acrossing Critical Speed Levitated by AMBs with Anisotropic Stiffness},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_090.pdf}
}
2018 Pilat, A.K. 6 Pole AMB as a Drive of Elliptic Rotor – Initial Study Supported by the Virtual Prototype Proceedings of ISMB16  
Abstract: This elaboration presents an initial study of the elliptic rotor driven by the active magnetic bearing consisting of 6 poles. The analysis was realized using the virtual prototype - a numerical model of device. The model was realized with support of COMSOL Multiphysics software. The proposed geometry, selected materials and configuration were used to perform analysis if the electromagnetic forces and torque are available to drive the rotor of the elliptic shape. The control study is given to obtain a rotational motion for a fixed rotor placement at the bearing center. Numerical simulations were realized to demonstrate features and limitations of the proposed solution. The solution in a form of Virtual Prototype allows to eliminate prototyping costs and extends the knowledge and dependencies of complex mechatronic systems like active magnetic levitation technology based ones.
BibTeX:
@inproceedings{ISMB16_091,
  author = {Adam Krzystof Pilat},
  title = {6 Pole AMB as a Drive of Elliptic Rotor – Initial Study Supported by the Virtual Prototype},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_091.pdf}
}
2018 Zhao, C., Sun, F., Jin, J., Xu, F., Pan, F. and Oka, K. Model Establishment and Simulation Analysis of Permanent Maglev Vehicle Proceedings of ISMB16  
Abstract: Based on the principle of variable magnetic flux, a permanent magnet suspension vehicle is proposed in this paper. The device adopts a four-point suspension structure and provides driving force through a permanent magnet gear. By changing the rotation angle of the disk permanent magnet of the four magnetic poles, the magnetic flux is changed. It could achieve the suspension force equal to gravity, so that the stable suspension of the device is realized. According to the suspension force model and the structure of prototype, a control decoupling system model is established. The decoupling strategy changes the four-point independent control into the control suspension vehicle with three degrees of freedom. The simulation results show that the decoupling control method is effective and worthy of further verification through experiments.
BibTeX:
@inproceedings{ISMB16_092,
  author = {Chuan Zhao and Feng Sun and Junjie Jin and Fangchao Xu and Fei Pan and Koich Oka},
  title = {Model Establishment and Simulation Analysis of Permanent Maglev Vehicle},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_092.pdf}
}
2018 Whitlow, Z., Knospe, C. and Fittro, R. Analytic Models for Nonlaminated Active Magnetic Thrust Bearings Proceedings of ISMB16  
Abstract: Analytic models for solid cylindrical electromagnetic actuators are extended to include geometries with a center hole, the configuration typical of thrust-type active magnetic bearings. These models describe the relationship between perturbation to coil current and the variations in mechanical force that result. The models are explicitly dependent on geometric and material properties of the actuator and include the effects of eddy currents, which determine the actuator bandwidth. These models are verified by comparison to high-fidelity finite element results.
BibTeX:
@inproceedings{ISMB16_093,
  author = {Zachary Whitlow and Carl Knospe and Roger Fittro},
  title = {Analytic Models for Nonlaminated Active Magnetic Thrust Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_093.pdf}
}
2018 Chen, R., Li, H., Ye, P., Tian, J. and Yu, W. Analysis of the Effect of Air Gap on the Performance of Self-inductance Displacement Sensor Proceedings of ISMB16  
Abstract: Inductive displacement sensor is one kind of the common sensors widely used in magnetic bearing system. In this paper, the working principle and output characteristics of the self-inductance displacement sensor are analyzed. For magnetic levitation rotor with a shaft diameter of 44.2mm, self-inductance displacement sensors with different air gaps are respectively designed. The magnetic field distribution and output characteristics of the designed sensor are simulated by finite element analysis method. Theoretical analysis and simulation results both show that there is a very good linear relationship between the output voltage and the rotor displacement of differential self-inductive displacement sensor when the displacement of rotor is in the range of -0.4 to 0.4(mm). Simulation results show the sensitivity of the self-inductance sensor is inversely proportional to the equilibrium air gap. With the increasement of air gap , the relative change value of total inductance is decreasing. When the rotor displacement is small relative to the equilibrium air gap, the relative change of total inductance is smaller and it can be considered unchanged. At this time, the amplitude of the current in the coil is basically unchanged when the voltage amplitude of the driving power is unchanged.
BibTeX:
@inproceedings{ISMB16_094,
  author = {Rui Chen and Hongwei Li and Pinzhou Ye and Jing Tian and Wentao Yu},
  title = {Analysis of the Effect of Air Gap on the Performance of Self-inductance Displacement Sensor},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_094.pdf}
}
2018 Gu, T., Zhang, Y. and Liu, S. Research on Influence of Annular Magnetic Pole on Airgap Magnetic Field and Bearing Capacity of Axial Magnetic Bearing Proceedings of ISMB16  
Abstract: In order to enhance the radial bearing capacity of the axial magnetic bearing, the magnetic field distribution of the air gap in the double-annular magnetic axial magnetic bearing and the three-annular magnetic axial magnetic bearing is simulated and studied, and the dual-ring magnetic pole shaft is established. Based on the magnetic circuit model of the magnetic bearing and the three-ring magnetic pole magnetic bearing, the effect of the annular magnetic pole on the air gap permeability and the total magnetic flux of the magnetic circuit was analyzed. The spatial distribution of air gap magnetic field between magnetic poles was obtained by finite element simulation. The distributions of axial and radial components of the air gap magnetic induction intensity were analyzed. Compared with the traditional single annular magnetic pole axial magnetic bearing structure, the multi-annular magnetic pole structure was enhanced. With the edge effect of the air gap flux, the proportion of the edge flux increases, and the axial flux ratio decreases. After that, the axial component of the magnetic induction intensity and the radial component of the radial displacement of the two-ring magnetic structure and the three-ring magnetic structure are compared and analyzed. The results show that the annular magnetic pole reduces the axial force and enhances the radial force, that is, the radial bearing capacity increases, and the axial component of the magnetic induction intensity of the three-ring magnetic structure is larger than that of the double-ring magnetic structure. The radial component of the displacement to the displacement is reduced, which provides a theoretical and experimental reference for the radial suspension of the annular magnetic axial magnetic bearing.
BibTeX:
@inproceedings{ISMB16_095,
  author = {Ting Gu and Yuzhe Zhang and Shuqin Liu},
  title = {Research on Influence of Annular Magnetic Pole on Airgap Magnetic Field and Bearing Capacity of Axial Magnetic Bearing},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_095.pdf}
}
2018 Yin, Z., Liu, Q., Zhao, M. and Zhao, Y. Spherical Magnetic Bearing With High Frequency and Dynamic Response Proceedings of ISMB16  
Abstract: To remedy the limitations of the single winding magnetic resistance bearing with slow dynamic response in magnetically suspended control sensitive gyroscope (MSCSG), a novel double windings spherical magnetic resistance bearing with high frequency and dynamic response is presented. The construction of MSCSG is introduced, and the work principle of novel double windings spherical magnetic resistance bearing is analyzed. The mathematical model of novel magnetic bearing is established by the equivalent magnetic circuit method, and the actual design of novel magnetic bearing is carried out. The simulation results are verified by the finite element numerical method. The mathematical model of the novel magnetic bearingrotor control system is derived through rotor dynamics, and the simulation model of the control system is established to simulate the response speed of the novel magnetic bearing. The results show that the response speed of the novel double winding magnetic resistance bearing with high dynamic response is nearly twice as high as that of the single winding magnetic resistance bearing. The results are in high agreement with the design values, which of great significance in high precision suspension support of spacecraft inertial actuators.
BibTeX:
@inproceedings{ISMB16_096,
  author = {Zhaojing Yin and Qiang Liu and Mingshi Zhao and Yong Zhao},
  title = {Spherical Magnetic Bearing With High Frequency and Dynamic Response},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_096.pdf}
}
2018 Allaire, P., Nichols, B., Dimond, T., Cao, J., Ma, X., Shang, R., Wang, C. and Wang, H. 5-Axis AMB Suspension Design for 300 HP Industrial Compressor Proceedings of ISMB16  
Abstract: This paper provides the design methodology, bearing geometries, and specifications for both the radial and axial AMBs as designed for an industrial 300 HP motor-blower unit. For each bearing design, the design principles and corresponding 1D circuit models are methodically presented and discussed. Next, the optimized bearing geometries and bearing properties are presented. The algorithms used by the design software, based on the 1D circuit model bearing analyses, refine the design process and verify the results using 2D finite element analysis (FEA). Based on calculated loads for the radial bearing and estimated loads for the thrust bearing, the radial AMB is designed for a load capacity of 2,000 N while the thrust bearing is designed for a load capacity of 3,000 N. The maximum rotational speed of the 200 KW unit is considered to be 21,000 rpm.
BibTeX:
@inproceedings{ISMB16_097,
  author = {Paul Allaire and Brad Nichols and Tim Dimond and Jianming Cao and Xianhao Ma and Raojing Shang and Chunyan Wang and Huajun Wang},
  title = {5-Axis AMB Suspension Design for 300 HP Industrial Compressor},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_097.pdf}
}
2018 Cao, J., Allaire, P., Nichols, B., Dimond, T., Ma, X., Shang, R., Wang, C. and Wang, H. Auxiliary Bearing Design and Rotor Drop Analysis of High Speed Motor Compressor/AMB System Proceedings of ISMB16  
Abstract: This paper presents the auxiliary bearing design and rotor drop analysis of a single stage motor-compressor. The auxiliary bearing design consists of double row, ceramic ball bearings with cages and with high axial preload. The axial preload is provided by Bellville washers which also provide axial spring stiffness and damping. The auxiliary bearings are laterally mounted on tolerance ring wave springs which provide support stiffness and damping to help absorb the impacts due to the rotor drop. A nonlinear transient rotor dynamics and auxiliary bearing modeling code has been utilized to carry out the rotor drop analysis. The very large mathematical model includes all of the shaft degrees of freedom, the auxiliary bearing races and all of the balls, as well as the Bellville washers and the wave springs. The rotor orbits, the inner and outer race orbits and the ball displacements are all evaluated versus time during the drop. The orbits were found to simply oscillate in the bottom of the auxiliary bearings and do not go into large orbit whirls. Also, the auxiliary bearing maximum compressive stress levels were evaluated and found to be well below the material yield stresses indicating long auxiliary bearing life in terms of number of drops without damaging the auxiliary bearings.
BibTeX:
@inproceedings{ISMB16_098,
  author = {Jianming Cao and Paul Allaire and Brad Nichols and Tim Dimond and Xianhao Ma and Raojing Shang and Chunyan Wang and Huajun Wang},
  title = {Auxiliary Bearing Design and Rotor Drop Analysis of High Speed Motor Compressor/AMB System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_098.pdf}
}
2018 Beneden, M.V., Kluyskens, V. and Dehez, B. Axial Force Evaluation in Permanent Magnet Thrust Bearings Subject to Demagnetization and Temperature Effects Proceedings of ISMB16  
Abstract: This article presents a 2D axisymmetric finite element model allowing to evaluate the axial force developed by a permanent magnet thrust bearings, including demagnetization and temperature effects. For this purpose, a linearized B-H curve is included in the model, with coefficients depending on the temperature. The axial force evaluation, as a function of the operating temperature is validated experimentally on a test bench. Finally, based on this model, the performance of thrust bearings using either SmCo or NdFeB are compared.
BibTeX:
@inproceedings{ISMB16_099,
  author = {Maxence Van Beneden and Virginie Kluyskens and Bruno Dehez},
  title = {Axial Force Evaluation in Permanent Magnet Thrust Bearings Subject to Demagnetization and Temperature Effects},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_099.pdf}
}
2018 Beneden, M.V., Kluyskens, V. and Dehez, B. Passive Compensation of the Temperature Effect on Permanent Magnet Thrust Bearing in Hybrid System Proceedings of ISMB16  
Abstract: Combining a permanent magnet thrust bearing (PMTB) with mechanical bearings inside a hybrid system can be a good compromise for some applications subject to high axial load. The guidance of the shaft is ensured by the mechanical bearings while those latter are relieved from the axial load by the magnetic bearing. However, as the permanent magnet properties depend on the temperature, this load relieve depends on the operating conditions. This paper describes a compensation system to maintain the force developed by the PMTB constant and independent from the temperature. This system consists in a soft spring placed in series with the static part of the PMTB allowing a variation of the airgap thickness. It is shown that when the stiffness of the soft spring is low enough compared to the equivalent stiffness of the PMTB, it is possible to maintain a constant load relieve for a wide range of operating temperature conditions. Practical implementations based on pressurized bellows are described.
BibTeX:
@inproceedings{ISMB16_100,
  author = {Maxence Van Beneden and Virginie Kluyskens and Bruno Dehez},
  title = {Passive Compensation of the Temperature Effect on Permanent Magnet Thrust Bearing in Hybrid System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_100.pdf}
}
2018 Mahmoud, M.S., Ueno, S. and Jiang, C. Vertical-Axis Wind Turbines Using Permanent Magnet Attractive Type Passive Magnetic Bearings Proceedings of ISMB16  
Abstract: This paper presents a novel design of a vertical axis wind turbine (VAWT) for power generation purposes. Using the effects of magnetic suspension, wind generator will be suspended on permanent magnets (PMs) as a replacement for ball bearings, which are normally used on conventional wind turbines. The features of this system are effective for saving energy, avoiding heat generation and preventing mechanical contact. Electrical power will then be generated with an axial flux generator, which incorporates the use of permanent magnets and a set of coils. The proposed VAWT model has the ability to achieve stability at different wind speeds in both the axial and radial direction. Moreover, the proposed model has a novel advantage consisting in adjustability of the axial and radial stiffness and ability to avoid critical speed reducing the vibration during the rotation of the wind turbine. The proposed model is characterized by simple structure and low-cost design. Finally, the effectiveness of the model is verified by the experimental results.
BibTeX:
@inproceedings{ISMB16_101,
  author = {Mahmoud S. Mahmoud and Satoshi Ueno and Changn Jiang},
  title = {Vertical-Axis Wind Turbines Using Permanent Magnet Attractive Type Passive Magnetic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_101.pdf}
}
2018 Zhang, G., Xie, C., Yuan, K., Song, X., Xu, J. and Zhou, D. Research on the Development of Permanent Magnetic Gas Suspension Bearing in ORC Waste Heat Generator Proceedings of ISMB16  
Abstract: High efficiency permanent magnet generator has been widely used in various applications due to its advantages of simple structure, high reliability, small size and high efficiency. However, under high speed condition, the energy loss of unit volume is increased by the mechanical friction generated for the traditional permanent magnet generator when using mechanical bearings. At the same time, oil and grease are not allowed to be used as lubricants in some ORC special occasions, so non-contact bearings are needed to replace mechanical bearings in high speed permanent magnet generators. The main objective of this paper is to develop a new type of permanent magnet gas suspension bearing and apply it to 200kW ORC waste heat permanent magnet generator. According to the specific condition of ORC waste heat permanent magnet generator to choose the appropriate structure of permanent magnetic bearing and gas bearing, and then considering the theory of porous hydrostatic gas bearing with generator and permanent magnet bearing (PMB) size to design the matching gas bearing. Meanwhile, in order to meet the requirement of strength and life, the 3D printing technology was applied to make the gas bearing liner with bearing which is a pioneer work. Then the whole structure design of the permanent magnet gas suspension bearing and the assemble of the bearing loading the ORC residual heat permanent magnet generator are done systematically. The simulation and experiment show that the development and design of ORC Waste Heat Generator supported by permanent magnet gas suspension bearing satisfy the design requirements.
BibTeX:
@inproceedings{ISMB16_102,
  author = {Gang Zhang and Caiqin Xie and Kunpeng Yuan and Xuan Song and Jinman Xu and Dian Zhou},
  title = {Research on the Development of Permanent Magnetic Gas Suspension Bearing in ORC Waste Heat Generator},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_102.pdf}
}
2018 Passenbrunner, J., Jungmayr, G. and Amrhein, W. Design of a Passively Magnetically Stabilized System with Viscoelastic Damping Support and Flexible Elements Proceedings of ISMB16  
Abstract: Using passively magnetically stabilized degrees of freedom in magnetic levitated reduces the complexity and therefore costs. In the investigated system only two degrees of freedom remain to be controlled actively. One is the rotation and the other is the axial position of the rotor, which is stabilized by an axial active magnetic bearing (AMB). However, the application of passive magnetic bearings (PMBs) features some drawbacks. One of the main problems is caused by the poor damping in PMBs, which leads to exaggerated deflection amplitudes in the resonance frequencies. This results in the necessity of external damping. One possibility is given by utilizing viscoelastic materials. But these materials show highly frequency and temperature dependent properties. Thus, only a proper model of the rotor dynamics including the nonlinear characteristics of the damping material allows for calculating the displacements of the system parts. Furthermore, also flexible parts have to be considered, if their bending modes fall within the range of operation. This article describes the rotor dynamic modeling of a passively magnetically stabilized system including the nonlinear behavior of a viscoelastic damping support as well as the consideration of the relevant flexible body modes. With this model an optimization can be performed to guarantee contact-free operation. Finally, the analytical model is verified by measurement.
BibTeX:
@inproceedings{ISMB16_103,
  author = {Josef Passenbrunner and Gerald Jungmayr and Wolfgang Amrhein},
  title = {Design of a Passively Magnetically Stabilized System with Viscoelastic Damping Support and Flexible Elements},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_103.pdf}
}
2018 Pavelka, J. and Kupka, P. Contribution to Design of Hybrid magnetic bearings Proceedings of ISMB16  
Abstract: Basic formulas for determining the magnetic force in the air gap of the electromagnet are derived at the beginning of this article. The application of these formulas for the heteropolar type and homopolar type AMB is described in the next sections of this article. The analysis of the magnetic circuit of the homopolar AMB with PM and three-phase excitation winding is given in Part IV. The formulas and recommendations for designing main dimensions of the AMB with PM are given in Part V.
BibTeX:
@inproceedings{ISMB16_104,
  author = {Jiri Pavelka and Pavel Kupka},
  title = {Contribution to Design of Hybrid magnetic bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_104.pdf}
}
2018 Zhang, L., Wu, H., Li, P., Hu, Y., Xu, C., Wang, L. and Zhang, Z. Design, Analysis and Experiment Study of the Permanent Maglev Roller used in Belt Conveyor Proceedings of ISMB16  
Abstract: The transport energy consumption of the belt conveyor can be reduced by using the maglev roller instead of the mechanical roller. In this research, the structure of permanent magnetic roller is studied. The mathematical model of the permanent magnetic bearing used in the roller is established by using the equivalent magnetic charge method (EMCM). Then the bearing characteristics of the permanent magnetic bearing are analyzed by using the finite element method (FEM). The structure parameters of the optimized magnetic levitation roller are obtained. Through the experiment study, the rotating resistance of the maglev roller can be reduced to 1.4N, which is far less than the design requirements of the mechanical rollers. And the radial round jump of the maglev roller is at 0.18-0.25mm, less than the radial round jump of the high quality mechanical roller. The analysis of the theory is verified.
BibTeX:
@inproceedings{ISMB16_105,
  author = {Li Zhang and Huachun Wu and Peng Li and Yefa Hu and Chuanyang Xu and Lei Wang and Ziyang Zhang},
  title = {Design, Analysis and Experiment Study of the Permanent Maglev Roller used in Belt Conveyor},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_105.pdf}
}
2018 Sikora, B. and Pilat, A.K. Hybrid Axial Active Magnetic Bearing – design, modelling and prototype Proceedings of ISMB16  
Abstract: This article presents concept, design, model and prototype of an hybrid axial magnetic bearing (HAMB). The numerical model developed in COMSOL Multiphysics is presented and analyzed. The manufactured stator and rotor were tested at the laboratory-test rig.
BibTeX:
@inproceedings{ISMB16_106,
  author = {Bartlomiej Sikora and Adam Krzysztof Pilat},
  title = {Hybrid Axial Active Magnetic Bearing – design, modelling and prototype},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_106.pdf}
}
2018 Zhao, X., Shuai, C., Xu, W., Chen, D. and Hu, Z. Force and Stiffness Calculation and Optimization of Permanent Magnetic Thrust Bearing Used in Vessels Proceedings of ISMB16  
Abstract: To isolate the vibration transmitted from the propeller to the vessel’s hull, the main engine, the shaft together with the bearings are proposed to be installed on a large-scale isolation system. Permanent magnetic thrust bearing (PMTB) is applied to further reduce the vibration transmission. The Coulombian model is adopted to calculate the force and stiffness, which determine the application feasibility of the PMTB in vessels. Explicit computations are presented for stacked PMTB. The calculation result is compared with that obtained by finite element method (FEM) and experimentally tested. It is revealed that the Coulombian model is accurate enough and more economic than the FEM, which make it advantageous to the structure design and parameter optimization of PMTB. In the influence study by Coulombian model, it is found that the airgap width can exponentially change the maximum axial magnetic force and stiffness; the radial width is not a sensitive factor for both force and stiffness; the axial length should be 4/5 of the radial thickness to obtain the largest force and decent stiffness.
BibTeX:
@inproceedings{ISMB16_107,
  author = {Xingqian Zhao and Changgeng Shuai and Wei Xu and Demin Chen and Zechao Hu},
  title = {Force and Stiffness Calculation and Optimization of Permanent Magnetic Thrust Bearing Used in Vessels},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_107.pdf}
}
2018 Poltschak, F. and Speletz, M. Reduction of Unbalanced Magnetic Forces in Planar Linear Actuators Proceedings of ISMB16  
Abstract: To reach a high axial thrust force density with planar linear motors slotted designs have advantages compared to the common air-gap winding topologies. Combined with a permanent magnet excitation compact solutions can be designed, which exhibit a significant force perpendicular to the direction of movement. Even with double sided topologies a destabilizing stiffness remains. This force adds up an extra load on the bearings and can significantly limit their life-time especially when bush bearings are applied. This paper introduces a concept to actively compensate for the permanent magnet induced bearing load. The potential and limits are analyzed based on a planar linear actuator with E-shaped stator cores and a four phase winding. It is outlined how an integrated active bearing force compensation can be reached for the complete axial stroke even with simple conventional actuator layouts. This method can (i) significantly reduce wear and thus improve lifetime and (ii) reduce the size of the mechanical bearings. The system simulation results are validated with measurements of a prototype system.
BibTeX:
@inproceedings{ISMB16_108,
  author = {Florian Poltschak and Markus Speletz},
  title = {Reduction of Unbalanced Magnetic Forces in Planar Linear Actuators},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_108.pdf}
}
2018 Sun, F., Zhou, R., Yan, M., Guo, Y., Jin, J. and Oka, K. Suspension Characteristics of a Zero-Power Permanent Magnet Suspension System With Flux Path Control Proceedings of ISMB16  
Abstract: A proposed permanent magnetic suspension using flux path control mainly consists of a disk permanent magnet, two pairs of F-type permalloy and a servo motor, and controls the suspension force by changing flux path, and the load on the motor shaft is eliminated due to its symmetric offset optimal structure to make the motor reach zero power output. In order to study the robustness of the system under external disturbances, this paper studies its suspension characteristics. Firstly, the structure and the suspension principle of the system are introduced. Secondly, the dynamic model is established, the controller of system is designed with the classic PD control method. Finally, the suspension characteristics of the system are studied through simulation and experiment. In the process of the experiment, the system is subjected to small step disturbance or small force disturbance, under the action of the real-time control system. The experimental results show that when the system is subjected to small step disturbance or small force disturbance in the process of the suspension, the suspended object will reach a new equilibrium position under the action of the real-time control system.
BibTeX:
@inproceedings{ISMB16_109,
  author = {Feng Sun and Ran Zhou and Mingyin Yan and Yongquan Guo and Junjie Jin and Koich Oka},
  title = {Suspension Characteristics of a Zero-Power Permanent Magnet Suspension System With Flux Path Control},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_109.pdf}
}
2018 Mrak, B., Lenaerts, B., Driesen, W. and Desmet, W. Optimal Design of Magnetic Springs; Enabling High Life Cycle Elastic Actuators Proceedings of ISMB16  
Abstract: Magnetic springs are an energy storage alternative to mechanical springs in applications that require long lifetime with no fatigue failure. Although this concept exists in academia for more than 30 years, industrial applications have been sparse. The goal of this article is twofold: (i) to position magnetic springs sideto- side with mechanical springs and (ii) develop a design methodology that will allow us to improve dynamic performance and/or reduce average and peak power consumption in highly dynamic industrial motion systems. Additionally, an extensive exploration of industrially feasible magnetic spring design space is performed using 2D finite element models combined with multiobjective genetic algorithm, resulting in Pareto-optimal fronts and parameter sets for each of the studied topology. Aside from geometry optimization, different magnetizations and permanent magnet materials are studied. Modelling efforts are validated on a physical prototype using both static and dynamic measurements of a two-pole magnetic spring within a dedicated setup. The validated results will be used within this paper to position magnetic spring assisted actuators back-to-back with classical industrial solutions.
BibTeX:
@inproceedings{ISMB16_110,
  author = {Branimir Mrak and Bert Lenaerts and Walter Driesen and Wim Desmet},
  title = {Optimal Design of Magnetic Springs; Enabling High Life Cycle Elastic Actuators},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_110.pdf}
}
2018 Komori, M., Hara, K., Asami, K. and Sakai, N. High Speed Rotor Using SMBs Working in Vacuum Chamber Proceedings of ISMB16  
Abstract: This study is performed to apply superconducting magnetic bearings (SMBs) to a high speed turbine rotor. First, we analyze the system by using finite element method and design the structure whose vibrations are suppressed well. Then, we have made an experimental setup using the theoretical result. The experimental setup consists of two SMBs, a permanent magnet (PM) motor and a rotor with many turbine blades. We perform some experiments using this experimental setup in a vacuum chamber. In this paper, we discuss the dynamic characteristics of the spinning rotor with many turbine blades.
BibTeX:
@inproceedings{ISMB16_111,
  author = {M. Komori and K. Hara and K. Asami and N. Sakai},
  title = {High Speed Rotor Using SMBs Working in Vacuum Chamber},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_111.pdf}
}
2018 Rodriguez, E., Costa, F. and Stephan, R. Vibration Analysis of a Superconducting Magnetic Bearing Under Different Temperatures Proceedings of ISMB16  
Abstract: Magnetic bearings offer the best solution to mitigate mechanical friction. A variety of geometries and new materials are being studied [5][6][7][8][9]. The advantage of using a passive bearing system, like the Superconducting Magnetic Bearing (SMB), is that it offers low friction without the need of feedback control, increasing the reliability and decreasing the energy consumption. SMB devices work at very low temperatures that are often achieved with the use of liquid nitrogen inside of cryostats. This paper describes the design and experimental tests of a SMB passive magnetic bearing system. An innovative design of a cryostat that uses YBCO bulks refrigerated by a cryocooler is presented. With this setup, it is possible to perform vibration tests in several temperatures from 45K up to 77K to find the resonance frequency on each axis at each temperature. Pieces of equipment that use SMB can benefit from reducing the working temperature [7][8][9]. The mechanical response of the pinning force may vary with the choice of refrigeration used. To perform those tests, units of accelerometers are installed on the rotor body to monitor the behavior . This improved magnetic bearing will be used in energy storage systems to reduce the instability of the rotor used in flywheel applications by changing the refrigeration temperature of the superconductor. This investigation can lead to an improvement of the levitation force, the levitation gap and damping.
BibTeX:
@inproceedings{ISMB16_112,
  author = {Elkin Rodriguez and Felipe Costa and Richard Stephan},
  title = {Vibration Analysis of a Superconducting Magnetic Bearing Under Different Temperatures},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_112.pdf}
}
2018 Zhao, Y., Murakami, I., Shimizu, M. and Ando, Y. Stabilization of Magnetic Repulsive Levitation System by Superconducting Magnetic Bearing Proceedings of ISMB16  
Abstract: In this research, we invented and produced a Superconducting magnetic bearing using repulsive permanent magnet. The repulsive magnetic levitation system with permanent magnet can generate strong levitation force without power supply. However, it is unstable except in the repulsion direction. In contrast, superconducting magnetic bearings can generate restoring force in all directions by utilizing the property of magnetic flux pinning of superconductors. Therefore, we constructed a superconducting magnetic bearing (SMB) which is stable in all axis without control and has a strong axial levitation force by combining a repulsive type magnetic levitation system and a superconducting magnetic levitation system. Furthermore, the driving test of the flywheel incorporating the SMB was carried out to verify the characteristics of the SMB. As a result of the experiment, it was confirmed that the flywheel could overcome the resonance and drive it. The maximum rotation speed of the flywheel was 10000[rpm].
BibTeX:
@inproceedings{ISMB16_113,
  author = {Yiming Zhao and Iwanori Murakami and Makoto Shimizu and Yoshinori Ando},
  title = {Stabilization of Magnetic Repulsive Levitation System by Superconducting Magnetic Bearing},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_113.pdf}
}
2017 Mitterhofer, H. Towards high-speed bearingless disk drives PhdThesis JKU Linz  
Abstract: Bearingless disk drives unite the functionality of magnetic bearings with electrical drives in a highly compact form with reduced mechanical complexity. The rotor field of a permanent magnet synchronous machine is used for passive stabilization in axial and tilt directions and, additionally, serves for the active creation of radial forces. This special magnetic levitation topology is being used in high-purity pumps in the pharmaceutical, medical, and the semiconductor industry which operate at low speeds. The research activities leading to this work proposed the use of bearingless disk drives for high rotational speeds for the first time. Many aspects of high-speed operation such as increased winding and stator core losses, or the special challenges in mechanical rotor design due to the high centrifugal forces are, therefore, being considered in this work. Equally, the ability to provide sufficient active radial forces and drive torque independently in an efficient fashion is a key specification for the bearingless operation. The design process includes the definition of suitable criteria which reflect the abovementioned drive properties and demonstrates the advantageous application of multiobjective numerical optimization to the problem. Special attention is also given to the problem of tilting motion in a dedicated chapter since many possible applications involve high-speed impellers or turbines with tight housing tolerances. As tilt-triggered gyroscopic whirl can lead to the destruction of the system, a novel electrodynamic stabilization coil is proposed and documented based on a corresponding experiment. As a result of the design process, several prototypes have been constructed, each realizing either a 5-phase double coil or a 6-phase single coil toroid winding concept using litz-wire and a low-loss slotless stator core. The prototype rotors comprise diametrically magnetized, ring-shaped rotors with high-strength support bandages and have a total outer rotor diameter between 30mm and 32mm. The developed radial position and rotational speed control loop with an underlying current controller features several non-linear extensions for reducing either losses, undesired rotor motion, or computation time. Different experiments for demonstrating the operational behavior, including rotor orbits during run-up and input power measurements have been conducted using this control scheme which was implemented at a standard DSP which controls a 10 half-bridge power electronic module. The maximum rotational speed reached during these experiments was 115 000 rpm which corresponds to a surface speed of 192.6m/s. To the knowledge of the author, this surface speed constitutes a world record for magnetically levitated disk drives. A detailed analysis of the losses provides analytic models for the iron losses, the eddy current winding losses, and the windage losses. Existing models have been matched to the loss measurements conducted at a customized test rig in order to allow an extrapolation of the expected losses at a speed of 200 000 rpm.
BibTeX:
@phdthesis{MISC1,
  author = {H. Mitterhofer},
  title = {Towards high-speed bearingless disk drives},
  school = {PhdThesis JKU Linz},
  year = {2017},
  url = {http://www.magneticbearings.org/wp-content/publications/misc/misc_1.pdf}
}
2017 Rudolph, J., Sieber, A. and Werner, R. Differentiation und Linearisierung von Messsignalen eines streuflussbasierten Messsystems für magnetisch gelagerte Rotoren Proceedings of Workshop on Magnetic Bearing Technology 11  
Abstract: In dem vorliegenden Beitrag wird auf Besonderheiten und Probleme eingegangen, die bei der Signalverarbeitung von stark verrauschten Signalen eines streuflussbasierten Messsystems zur Bestimmung der Rotorposition in einem heteropolaren Magnetlager auftreten. Besonders die zeitliche Ableitung der Steuerströme zur Kompensation von Feldverzögerungseffekten verursacht Probleme, für die in dieser Arbeit Lösungsansätze vorgestellt werden. Im Anschluss wird die Umsetzung auf einem Echtzeitbetriebssystem mithilfe von MATLAB-Simulink beschrieben.
BibTeX:
@inproceedings{WMLT11_1,
  author = {J. Rudolph and A. Sieber and R. Werner},
  title = {Differentiation und Linearisierung von Messsignalen eines streuflussbasierten Messsystems für magnetisch gelagerte Rotoren},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 11},
  year = {2017},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt11/wmlt11_1.pdf}
}
2017 Lorenz, F., Rudolph, J. and Werner, R. Herstellung elektromagnetisch aktiver Strukturen mittels 3D Multimaterialdruck Proceedings of Workshop on Magnetic Bearing Technology 11  
Abstract: Additive Fertigungsverfahren werden zuneh-mend für die Herstellung von Konsum- und In-dustrieprodukten eingesetzt. Neben den weit verbreiteten, kunststoffbasierten 3D-Druckver-fahren sind Laser-Pulverbett-basierte Techno-logien etabliert, mit denen komplexe, hochbe-lastbare Funktionsbauteile hergestellt werden können. Die aktuell verfügbaren Anlagen sind jedoch weitestgehend auf die Verarbeitung nur eines Werkstoffes bzw. einer Werkstoffgruppe (Kunststoff) begrenzt. Die Herstellung komple-xer Funktionsbaugruppen erfordert darüber hinaus die gleichzeitige Verarbeitung mehrerer Werkstoffe mit unterschiedlichen physikali-schen Eigenschaften. Der vorliegende Beitrag stellt ein neuartiges Fertigungsverfahren vor, das die Realisierung komplexer Multimaterial-bauteile aus Metallen sowie Keramiken ermög-licht und somit die Herstellung physikalisch an-spruchsvoller Baugruppen zulässt. Die Herstel-lung elektromagnetisch aktiver Strukturen steht dabei im Fokus.
BibTeX:
@inproceedings{WMLT11_2,
  author = {F. Lorenz and J. Rudolph and R. Werner},
  title = {Herstellung elektromagnetisch aktiver Strukturen mittels 3D Multimaterialdruck},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 11},
  year = {2017},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt11/wmlt11_2.pdf}
}
2017 Vanek, C. and Worlitz, F. Eignung von Gleitlagern als Fanglager für schwere magnetgelagerte Rotoren bei erhöhten Temperaturen Proceedings of Workshop on Magnetic Bearing Technology 11  
Abstract: Der zunehmende Einsatz von Magnetlagern im industriellen Umfeld stellt immer höhere Anforderungen an die eingesetzten Komponenten bezüglich der Robustheit gegenüber extremen Umgebungsbedingungen. Extreme Umgebungsbedingungen sind hohe Temperaturen (> 200C) und/oder die Anwesenheit von aggressiven Medien. Neben der Ertüchtigung der Magnetlager muss auch die Fanglagerung unter diesen Umgebungsbedingungen zuverlässig funktionieren. Der Beitrag soll zeigen, welche Herausvorderungen bestehen, eine solche Fanglagerung auszulegen. Weiterhin soll das geplante Gleitfanglagermodell und die Validierungsstrategie für dieses Modell vorgestellt werden.
BibTeX:
@inproceedings{WMLT11_3,
  author = {C. Vanek and F. Worlitz},
  title = {Eignung von Gleitlagern als Fanglager für schwere magnetgelagerte Rotoren bei erhöhten Temperaturen},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 11},
  year = {2017},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt11/wmlt11_3.pdf}
}
2017 Shmachkov, M., Noack, I. and Worlitz, F. Das leistungsfähige und modulare Werkzeug Maglap++ zur Zustandsdiagnose und Überwachung magnetgelagerter Maschinen Proceedings of Workshop on Magnetic Bearing Technology 11  
Abstract: Moderne aktive Magnetlager sind hoch präzise mechatronische Systeme, deren Überwachung, Zustandsdiagnose und Analyse spezielle Anforderungen mit sich bringen. Diese müssen auch von der zu verwendenden Software zur Messwerterfassung, Datenspeicherung und -verarbeitung erfüllt werden. Ein solches Messwerterfassungssystem ist eine komplexe Software, die vor allem schnell und genau arbeiten muss. Die bisherigen Umsetzungen unterlagen einigen Einschränkungen, die sich nachteilig auf Effizienz, Erweiterbarkeit und Programmdesign auswirkten. Ebenfalls problematisch sind die verwendeten Lizenzmodelle und die fehlende Quellcodetransparenz in der Software. Für das Forschungspersonal ist nicht ersichtlich, wie interne Funktionen (auch Module usw.) arbeiten und wie sie in bestimmten Situationen reagieren. Um diesen Problemen und Begrenzungen entgegenzuwirken, wurde am Institut für Prozeßtechnik, Prozeßautomatisierung und Meßtechnik (IPM) mit der Entwicklung der Software „Magnetlagerprogramm“ (Maglap++, Logo: Abb. 1) begonnen.
BibTeX:
@inproceedings{WMLT11_4,
  author = {M. Shmachkov and I. Noack and F. Worlitz},
  title = {Das leistungsfähige und modulare Werkzeug Maglap++ zur Zustandsdiagnose und Überwachung magnetgelagerter Maschinen},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 11},
  year = {2017},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt11/wmlt11_4.pdf}
}
2017 Neumann, H., Pantke, K., Frantzheld, J. and Worlitz, F. Entwicklung und Bau eines neuartigen magnetischen Momentenlagers Proceedings of Workshop on Magnetic Bearing Technology 11  
Abstract: In der Regel wird die vollständig aktive Magnetlagerung eines Rotors durch zwei Radial- und ein Axialmagnetlager realisiert. Für Anwendungen, bei denen die axiale Ausdehnung des Rotors zur Unterbringung eines zweiten Radiallagers nicht ausreicht, sind alternative Lösungsansätze notwendig. Nachfolgend wird die Auslegung, Simulation und experimentelle Validierung am Beispiel eines Demonstrators in Außenläuferbauweise vorgestellt. Außerdem werden der Bau und die Inbetriebnahme eines Prototyps zur Lagerung eines Computertomographen vorgestellt.
BibTeX:
@inproceedings{WMLT11_5,
  author = {H. Neumann and K. Pantke and J. Frantzheld and F. Worlitz},
  title = {Entwicklung und Bau eines neuartigen magnetischen Momentenlagers},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 11},
  year = {2017},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt11/wmlt11_5.pdf}
}
2017 Schleicher, A. and Werner, R. Beruehrungsloses 6-Achs-Messsystem fuer lagerlose reluktante Rotations-Linearmotoren Proceedings of Workshop on Magnetic Bearing Technology 11  
Abstract: In diesem Beitrag wird ein berührungsloses Messsystem für die Messung von Verdrehungen und Verschiebungen in 6 Freiheitsgraden vorgestellt. Das Messsystem ist speziell für einen neuartigen Antrieb, den lagerlosen reluktanten Rotations-Linearmotor, entwickelt worden, kann jedoch leicht auch für andere Zwecke modifiziert werden. Für den Einsatz in diesem Spezialantrieb werden hohe Anforderungen gestellt, welche nicht alle von einzelnen konventionellen Messsystemen erfüllt werden können. Daher wurde ein Gesamtsystem aus aufeinander sowie auf die Messaufgabe abgestimmten Einzelmesssystemen entwickelt. Dieses besteht aus einem kapazitiven Mehrachs-Messsystem mit neuartiger differenzieller Sensorik und Auswertung sowie aus einem inkrementellem Laser-Messsystem in Differenzialanordnung.
BibTeX:
@inproceedings{WMLT11_6,
  author = {A. Schleicher and R. Werner},
  title = {Beruehrungsloses 6-Achs-Messsystem fuer lagerlose reluktante Rotations-Linearmotoren},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 11},
  year = {2017},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt11/wmlt11_6.pdf}
}
2017 Duesterhaupt, S. and Worlitz, F. Zuverlässigkeitsbewertung aktiver Magnetlagerungen unter der Berücksichtigung erweiterter Umgebungsbedingungen Proceedings of Workshop on Magnetic Bearing Technology 11  
Abstract: Aktive Magnetlagerungen können in modernen Industrieapplikationen wie Turbomaschinen eine Schlüsseltechnologie darstellen. Gegenwärtig berücksichtigt der Designprozess Nennwerte in der statischen Auslegung und dyna-mischen Simulation des magnetgelagerten Sys-tems. Im praktischen Einsatz jedoch beeinflussen der Prozess und die Umgebung die Funktionsweise der Sensoren, Leistungsverstärker und magnetischen Aktoren. Insbesondere der thermische Einfluss verursacht mehr oder minder starke Driften in den Komponenten- und Bauteilparametern. Die Ursachen dafür können hohe Umgebungstemperaturen sein oder mechanische Stützanregungen bzw. Druckänderungen. Die mechanischen Einflüsse führen zu einer zunehmenden Relativbewegung zwischen Rotor und Stator. Infolge der Auslen-kungen reagiert das aktive Magnetlager mit Regeleingriffen. Die Steuerstromänderungen führen zu einer veränderten Eigenerwärmung der Leistungssteller und Lagerspulen. Die arbeitspunkt- und lastabhängige Beeinflussung der Lagerkomponenten führt letztendlich zu einer veränderten Dynamik der Lage- und ggf. der unter-lagerten Stromregelkreise. Ein unter Nominalbedingungen funktionsfähiges aktives Magnetlager versagt ggf. aufgrund mechanischer, elektrischer und magnetischer Parameterdriften. Für den Einsatz muss daher die Zuverlässigkeit des mechatronischen Systems objektiv nachgewiesen werden. Dies muss unter der Berücksichtigung von Prozess und Umgebung erfolgen.
BibTeX:
@inproceedings{WMLT11_7,
  author = {S. Duesterhaupt and F. Worlitz},
  title = {Zuverlässigkeitsbewertung aktiver Magnetlagerungen unter der Berücksichtigung erweiterter Umgebungsbedingungen},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 11},
  year = {2017},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt11/wmlt11_7.pdf}
}
2017 Seifert, R., Fleischer, E. and Hofmann, W. Experimentelle Bestimmung der Rotorverluste eines dreipoligen kombinierten Radial-/Axialmagnetlagers aus Pulververbundwerkstoffen Proceedings of Workshop on Magnetic Bearing Technology 11  
Abstract: In Vakuumanwendungen, wie Molekularpumpen oder Schwungradenergiespeichern, treffen oftmals hohe Drehzahlen auf schwierige Kühlbedingungen. Es besteht daher der Bedarf nach aktiven Magnetlagern mit einem besonders geringem Leistungsbedarf sowie geringen Ummagnetisierungsverlusten im Rotor. Die zur Verlustminimierung prädestinierten Pulververbundwerkstoffe (SMC - Soft Magnetic Composites) finden aufgrund ihrer geringen mechanischen Festigkeit bisher keine Anwendung in industriellen Hochgeschwindigkeitsanwendungen. In diesem Artikel wird das DFG-Projekt 'Verlustarme magnetische Radial-/Axiallagerung unter Verwendung von Pulververbundwerkstoffen' zusammengefasst sowie abschließend der experimentelle Nachweis erbracht, dass die neu entwickelte dreipolige Lagerstruktur mit kombiniertem Radial- und Axiallager den Einsatz von SMC auch bei Drehzahlen von bis zu 30 000 min1 erlaubt. Eine Projizierung der Messergebnisse auf verlustoptimierte industrielle SMC-Sorten verspricht zudem ein Reduzierungspotential der Ummagnetisierungsverluste von mindestens 23 – 44%, wobei insbesondere kompakte und hochausgenutzte Geometrien im Vorteil sind.
BibTeX:
@inproceedings{WMLT11_8,
  author = {R. Seifert and E. Fleischer and W. Hofmann},
  title = {Experimentelle Bestimmung der Rotorverluste eines dreipoligen kombinierten Radial-/Axialmagnetlagers aus Pulververbundwerkstoffen},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 11},
  year = {2017},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt11/wmlt11_8.pdf}
}
2017 Rottenbach, T., Vanek, C. and Worlitz, F. Auswirkungen hoher Temperaturen auf die Auslegung und Gestaltung aktiver Magnetlager Proceedings of Workshop on Magnetic Bearing Technology 11  
Abstract: Der Einsatz aktiver Magnetlager an Turbomaschinen in Kraftwerken führt aufgrund der wesentlich geringeren Lagerreibung und dem Wegfall der Ölschmierung zu einer Verbesserung des Gesamtwirkungsgrades des Aggregates. Dieser wird jedoch erheblich reduziert, da die über die Welle in die Magnetlager eingeleitete Pro-zesswärme durch geeignete Kühlmaßnahmen abgeführt werden muss. Alternativ dazu sind Konzepte, die auf eine Erhöhung der Grenztemperaturen der Isolation der Lagerspulen und der Rotor- bzw. Statorbleche durch temperaturbeständigere Isolierstoffe abzielen. Der Bei-trag gibt, ausgehend von den Auswirkungen hoher Temperaturen auf die elektrischen, magnetischen und mechanischen Eigenschaften der Magnetkreismateria-lien, einen Überblick über verfügbare Werkstoffe und deren Hersteller/Anbieter sowie auf den Auslegungs- bzw. Designprozess von Magnetlagern.
BibTeX:
@inproceedings{WMLT11_9,
  author = {T. Rottenbach and C. Vanek and F. Worlitz},
  title = {Auswirkungen hoher Temperaturen auf die Auslegung und Gestaltung aktiver Magnetlager},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 11},
  year = {2017},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt11/wmlt11_9.pdf}
}
2016 Sugino, M., Nagashima, K., Ogata, M., Yamashita, T., Matsue, H., Miyazaki, Y. and Horiuchi, S.-I. The development of the flywheel energy storage system applying the high temperature superconducting magnetic bearing - The examination of a demonstration machine by having it charged/discharged with solar photovoltaic power Proceedings of ISMB15  
Abstract: The flywheel energy storage systems (FESS) that can stabilize the fluctuation of the output of the solar photovoltaic power generation system have been developed as a joint project of five enterprises. In this project, a FESS demonstration machine was developed and the examination of the machine was conducted in such a way as to alternate charge and discharge with solar photovoltaic power using this machine. This project was implemented for 4 years. The main devices were assembled so as to be completed as the FESS demonstration machine in an assembly plant. After the completion of the FESS demonstration machine, the machine was reinstalled in the examination plant that is located in Kofu City, Yamanashi Prefecture. The charging/discharging examination with solar photovoltaic power was conducted after the reinstallation. And it was confirmed that the FESS demonstration machine has the ability necessary for stabilizing the solar photovoltaic power generation.The occurrence of the blackout was assumed as the abnormality that would occur when the FESS demonstration machine is really operated, and the simulated blackout examination was conducted and it was confirmed that the FESS demonstration machine was able to stop safely even in cases where a blackout in operation occurred. With the completion of all the examinations in February 2016, the development project of the FESS demonstration machine was completed. The FESS demonstration machine can stabilize the photovoltaic power generation, and it can stop safely when a blackout in operation occurs. The above mentioned performances of the FESS demonstration machine were confirmed by the results of the performance evaluation examinations.
BibTeX:
@inproceedings{ISMB15_1,
  author = {Motohiko Sugino and Ken Nagashima and Masafumi Ogata and Tomohisa Yamashita and Hitoshi Matsue and Yoshiki Miyazaki and Shin-Ichi Horiuchi},
  title = {The development of the flywheel energy storage system applying the high temperature superconducting magnetic bearing - The examination of a demonstration machine by having it charged/discharged with solar photovoltaic power},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_1.pdf}
}
2016 Machida, Y. and Oka, K. Impact of Inclination of Teeth for Bearingless Motor with Non-contact Power Supply Proceedings of ISMB15  
Abstract: A new type of bearingless motor has been developed. The feature of this bearingless motor is no use of permanent magnets. The rotor is magnetized by a current of a non-contact power supply, which consists of a bridge rectifier circuit and coils. Levitation is achieved through attractive forces generated by inclinations on the edges of the rotor and the stator. In the previous study, levitation of a prototype system could not be achieved. It was posited that the inclination of edges decreases restitutive force, which is used to control the tilting motion of the rotor. In this paper, the impact of the inclination of the edges on the decrease of restitutive force was investigated and confirmed by 3D-FEM analysis. Additionally, levitation of the prototype system was investigated by simulating the displacement of the rotor with both linear and non-linear rotor models. Finally, the control principle was changed according to findings of this study and the controllable range of the rotor was calculated.
BibTeX:
@inproceedings{ISMB15_10,
  author = {Yohei Machida and Koichi Oka},
  title = {Impact of Inclination of Teeth for Bearingless Motor with Non-contact Power Supply},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_10.pdf}
}
2016 Kurvinen, E. and Fittro, R. Advanced Control Performance in Compressor Surge Proceedings of ISMB15  
Abstract: Single stage compressors supported in magnetic bearings are known to exhibit compromised capacity to handle loads associated with compressor surge and stall - generally in a frequency range from about 10 Hz to 100 Hz. The present work studies utilization of advanced control in order to achieve high machine load capacity at these frequencies. A case study of a machine similar to a chiller compressor was used to study the performance with a generalized, multiple-input multiple-output (MIMO) H-infinity control with different input weighting. In the study, the machine load capacity, i.e., radial load at impeller location at different frequencies is studied. It was found that H-infinity control can achieve high machine load capacity over surge and stall frequencies (0 to 100 Hz) and in addition, it can achieve nearly the theoretical capacity limit. This type of controller enables the design of the input weighting to achieve good performance over the desired frequency range. This observation provides motive to more strongly consider advanced MIMO control methods for active magnetic bearings especially in compressor type applications.
BibTeX:
@inproceedings{ISMB15_100,
  author = {Emil Kurvinen and Roger Fittro},
  title = {Advanced Control Performance in Compressor Surge},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_100.pdf}
}
2016 Di, L. and Yoon, S.Y. Autobalancing of AMB Systems Using a Differential Regulator Based Output Regulation Approach Proceedings of ISMB15  
Abstract: High speed rotating machines are subject to unbalance forces caused by residue weight. When the rotor’s axis of geometry and its principal axis of inertia are not aligned, unbalance forces synchronous to the rotational speed cause the rotor to deflect from the geometric center and enter a whirling motion. To reduce the effects that the rotor unbalance has on high speed machineries supported by AMBs, the conventional approach has been to either generate counteracting bearing forces or to shift the rotating axis in such a way that the shaft is rotating force-free or performing auto-balancing. In this paper, a differential regulator based output regulation approach is presented to address the autobalancing of AMB systems for varying rotational speeds. After formulating the output regu- lation problem with a time-varying exosystem, it is observed that the compensator gains can be obtained based on the solution of the differential regulator equation (DRE) and the output regulation objective can be achieved approximately with a small bounded error in the regulated output. The proposed method is verified in simulation for autobalancing with both varying and constant rotational speeds on a flexible rotor AMB test rig.
BibTeX:
@inproceedings{ISMB15_101,
  author = {Long Di and Se Young Yoon},
  title = {Autobalancing of AMB Systems Using a Differential Regulator Based Output Regulation Approach},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_101.pdf}
}
2016 Levy, R. and Arogeti, S. Inertial Centering of Magnetically Suspended Flexible Rotors Proceedings of ISMB15  
Abstract: When an unbalanced flexible rotor reaches a steady state, where it is not vibrating but spinning with a constant geometric shape, it can be assumed (to some extent) a rigid body. Under this assumption, an inertial centering controller is developed for a general flexible AMB-rotor system with multiple mass imbalances. It is shown that in the absence of gyroscopic effects, the inertial center of a discretized flexible rotor can be observed as an independent set of coordinates with static and dynamic imbalance. However, more information is needed to implement an imbalance compensation in the presence of gyroscopic effects. In addition, the stability of the closed loop system is discussed and a case study of 8-DoF flexible rotor is presented. The theory is approved by numerical simulations which result in a complete suppression of more than 420N synchronous force.
BibTeX:
@inproceedings{ISMB15_102,
  author = {Rami Levy and Shai Arogeti},
  title = {Inertial Centering of Magnetically Suspended Flexible Rotors},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_102.pdf}
}
2016 Zhao, J., Sun, Z., Yan, X. and Shi, Z. Field Dynamic Balancing System Based on Labview in AMB-Flexible Rotor System Proceedings of ISMB15  
Abstract: The 10MW high temperature gas-cooled test module reactor (HTR-10GT) with the core made of spherical fuel elements was designed and constructed by the Institute of Nuclear and New Energy Technology of Tsinghua University in China. In the HTR-10GT,turbo-compressor and generator rotors are connected by a flexible coupling and a decelerator. The AMB is the important technology for the helium blower. AMB rotor commonly has high working speed, although on the theory base, you can raise winding rigidity at discretion through feedback control, in fact, because of the limit of AMB power, if dynamic balancing is not good, it will easily cause electric current saturated phenomenon and make the base of bearings cause fierceness vibration. SO it is quite essential to make precision dynamic balancing for high speed AMB rotor. In this paper significance of dynamic balance for the AMB system is discussed and as well vibration monitoring and field dynamic balance system for the AMB system is constructed. The feasibility of the dynamic balance system is tested through experiments in the paper.
BibTeX:
@inproceedings{ISMB15_103,
  author = {Jingjing Zhao and Zhe Sun and Xunshi Yan and Zhengang Shi},
  title = {Field Dynamic Balancing System Based on Labview in AMB-Flexible Rotor System},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_103.pdf}
}
2016 Dumont, C., Gilson, A., Kluyskens, V. and Espanet, C. Evaluation of the Electrodynamic Forces in a High-Speed Permanent Magnet Machine with Rotor Eccentricity Proceedings of ISMB15  
Abstract: In permanent magnet motors, the presence of rotor eccentricities can alter the airgap field distribution. This results in parasitic radial detent forces that can be reduced by connecting the stator phases in parallel. As a consequence, currents are passively induced in the windings when the rotor spins in an off-centered position, yielding balancing electrodynamic forces. Specific models were developed to predict these forces, but their complexity can be pro- hibitive. Therefore, this paper proposes to study the effect of the rotor off-centering in permanent magnet motors using a simpler model developed for electrodynamic bearings. This model consists in a linear differential equation with only four parameters that depend neither on the spin speed nor on the rotor position. As an illustration, the paper applies this model to the study of a high-speed, slotted permanent magnet motor. To support this, the main hypotheses of the model are validated in this particular case. Finally, the centering electrodynamic forces in a quasi-static configuration are predicted using the model and compared to finite element simulation results.
BibTeX:
@inproceedings{ISMB15_104,
  author = {Corentin Dumont and Adrien Gilson and Virginie Kluyskens and Christophe Espanet},
  title = {Evaluation of the Electrodynamic Forces in a High-Speed Permanent Magnet Machine with Rotor Eccentricity},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_104.pdf}
}
2016 Suzuki, H., Kanamaru, M., Sato, M., Tokunaga, S., Kainuma, S. and Ito, A. Round Layout Halbach Array using Cylinder Shaped Permanent Magnets Proceedings of ISMB15  
Abstract: The purpose of the study was to examine the sliding performance of the magnetic field above a Halbach array constructed with cylindrical permanent magnets, and explore a variety of advanced layouts. Halbach arrays are effective in forming a strong magnetic field. However, the magnetic field in a conventional model is difficult to control because all the rectangular-shaped permanent magnets are strongly fixed. The proposed Halbach array was constructed with eleven cylinder-shaped permanent magnets magnetized in the radial direction. In the proto-model of a Halbach array using cylindrical permanent magnets and synchronized rotation in the same direction of all magnets, the slide of the magnetic field distribution was confirmed by quasi-static measurement and simulation of magnetic field. The slide performance of the magnetic field is believed to contribute to the high performance of magnetic actuation, and further, a novel layered or round layout Halbach array has led to the development of a new model actuator. In this paper, we present two round layout models having the characteristics of magnetic field control and constitutive flexibility and we show preliminary results by magnetic field analysis.
BibTeX:
@inproceedings{ISMB15_105,
  author = {Haruhiko Suzuki and Masatoshi Kanamaru and Mizuki Sato and Shogo Tokunaga and Shuichiro Kainuma and Atsushi Ito},
  title = {Round Layout Halbach Array using Cylinder Shaped Permanent Magnets},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_105.pdf}
}
2016 Cui, Q., Napoli, M.D., Detoni, J. and Amati, N. A Systematic Approach for Modeling and Identification of Eddy Current Dampers in Rotordynamic Applications Proceedings of ISMB15  
Abstract: Eddy current dampers (ECDs) exploit Lorentz forces due to the induced eddy currents in a conductor subject to a time–varying magnetic field. ECDs can be used to introduce damping in rotordynamic applications without mechanical contact to the rotor, thus introducing negligible impact on the dynamic response of the whole system. They are suitable for applications where contactless support of a rotor is required, thus being a perfect match for passive magnetic bearings such as permanent magnet bearings and superconducting bearings. However, modeling and identification of the amount of damping induced by ECDs is a difficult task due to complicated geometry and working conditions. A novel and systematic approach for modeling and identification of the damping characteristics of ECDs in rotordynamic applications is proposed in the present paper. The proposed approach employs an analytical dynamic model of the ECD and curve fitting with results of finite element (FE) models to obtain the parameters characterizing the ECD’s mechanical impedance. The damping coefficient can be obtained with great accuracy from a single FE simulation in quasi-static conditions. Finally, the accuracy of the identification approach is verified by comparing the results with experimental tests. The validity of this approach is in the cases where ECDs employ an axisymmetric conductor, thus covering most cases in rotordynamic applications.
BibTeX:
@inproceedings{ISMB15_106,
  author = {Qingwen Cui and Maria Di Napoli and Joaquim Detoni and Nicola Amati},
  title = {A Systematic Approach for Modeling and Identification of Eddy Current Dampers in Rotordynamic Applications},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_106.pdf}
}
2016 Wu, H., Ren, Y., Yang, S. and Hu, Y. Design of Permanent Magnet Levitation Roller for Belt Conveyer Proceedings of ISMB15  
Abstract: Roller is an important component for the belt conveyor. The function of roller is supporting conveyor belt, to ensure the belt conveyor smooth operation. This study aims at the working condition of the roller of long-distance belt conveyor, which suffers from severe wear of mechanical bearing and belt, large rotational resistance, huge power dissipation, large vibration and noise. A new type of maglev roller is designed, which is supported by permanent magnetic bearing (PMB), but the axial force is restrained by mechanical force. The finite element method (FEM) was employed to analyze and design the structure and magnetic circuit of the permanent magnet levitation roller. The structure parameters of magnet levitation roller were optimized. The simulation and test results have proven the proposed bearing feasible and effective.
BibTeX:
@inproceedings{ISMB15_107,
  author = {Huachun Wu and Yongwu Ren and Shiping Yang and Yefa Hu},
  title = {Design of Permanent Magnet Levitation Roller for Belt Conveyer},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_107.pdf}
}
2016 Cao, J., Allaire, P., Dimond, T. and Rensburg, J.J.V. Rotor Drop Analyses and Auxiliary Bearing System Optimization for AMB Supported Rotor - Part I: Analysis Method Proceedings of ISMB15  
Abstract: For rotors supported with active magnetic bearings (AMBs), the auxiliary bearing system (AUX) is needed to avoid potential severe internal damaging due to AMB loss power or overload. The evolution of auxiliary systems has been required by the American Petroleum Institute (API) using analytical or experimental methods. In part I of this paper, a detailed rotor drop transient analysis method including flexible shaft, rolling element bearing components, as well as flexible/damped supporting structures is given. Part 2 gives the experimental validation of the method with a test rig and model optimization. A finite element based flexible rotor model is used to indicate the shaft motion before the drop (operating conditions) and during the rotor drop event. Un-lubricated Hertzian contact models are used for the shaft and inner races, for balls and races. To avoid heavy time consumption, two different methods, which calculate the ball bearing contact loads, are discussed and the simulation results are compared. These models are applied to predict shaft-race-ball displacements and angular speeds, contact loads and ball bearing stresses during the drop for auxiliary bearings. This method also can be used to design and optimize the auxiliary bearing system as presented in the 2nd part of this paper, based upon the experimental testing results and validation.
BibTeX:
@inproceedings{ISMB15_108,
  author = {Jianming Cao and Paul Allaire and Tim Dimond and Jan Janse Van Rensburg},
  title = {Rotor Drop Analyses and Auxiliary Bearing System Optimization for AMB Supported Rotor - Part I: Analysis Method},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_108.pdf}
}
2016 Cao, J., Allaire, P., Dimond, T. and Rensburg, J.J.V. Rotor Drop Analyses and Auxiliary Bearing System Optimization for AMB Supported Rotor - Part II: Experiment and Optimization Proceedings of ISMB15  
Abstract: This paper forms Part II of the rotor drop analysis, focusing on the auxiliary bearing system design and optimization based on the rotor drop analysis methods, as introduced in Part I. Optimization focuses on shaft orbit, maximum ball bearing stress, and how to avoid possible ball bearing damage due to impact loading during rotor drop by optimizing auxiliary design including bearing selection, preload method, radial and axial damping element, and flexible bearing support. The rotor drop modeling process has been validated with test rig result. Using the detailed rotor drop model and time transient method, simulation results are first compared with test data; and a simulation is presented for an 8-stage horizontal centrifugal compressor, are conducted to investigate the effects of auxiliary bearing design and to optimize the auxiliary system. Axial drops, radial drops and combination of radial/axial drops are all evaluated considering angular contact auxiliary bearing size, number of rows, preload, and flexible damped bearing supports in the axial and radial directions. The rotor drop analysis method introduced in this paper may be used as a design toolbox for the auxiliary bearing system.
BibTeX:
@inproceedings{ISMB15_109,
  author = {Jianming Cao and Paul Allaire and Tim Dimond and Jan Janse Van Rensburg},
  title = {Rotor Drop Analyses and Auxiliary Bearing System Optimization for AMB Supported Rotor - Part II: Experiment and Optimization},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_109.pdf}
}
2016 Schuck, M. and Steinert, D. Torque Interaction of the Drive and Active Radial Magnetic Bearing in an Ultra-High Speed Spinning Ball Motor Proceedings of ISMB15  
Abstract: The ongoing miniaturization trend of electric machines increases the demand for higher rotational speeds to provide a required power level at decreased size. The goal of this project is to push the limits of rotor miniaturization by researching new concepts for ultra-high speed machines achieving rotational speeds above 20 million rotations per minute (Mrpm). Such high rotational speeds can only be attained by limiting the centrifugal loading on the rotor, which can be accomplished by decreasing its size to less than 1 mm in diameter. Furthermore, the rotational losses have to be minimized. This requires precise and fast frictionless magnetic bearings for stabilization of the rotor in all dimensions, which interfere with the drive system of the motor by generating a breaking torque and torque ripples. The interaction is studied in this paper based on an analytical model and transient finite element method (FEM) simulations. The occurring torque components are identified and guidelines for the design of the radial magnetic bearing are provided. By incorporating these guidelines into the machine design, acceleration of the rotor to the desired rotational speeds can be achieved.
BibTeX:
@inproceedings{ISMB15_11,
  author = {Marcel Schuck and Daniel Steinert},
  title = {Torque Interaction of the Drive and Active Radial Magnetic Bearing in an Ultra-High Speed Spinning Ball Motor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_11.pdf}
}
2016 Quurck, L. Planetary Backup Bearings for High Speed Applications and Service Life Estimation Methodology Proceedings of ISMB15  
Abstract: Backup bearings (BB) limit the rotor translational movement during malfunction, overload or power loss in the active magnetic bearings (AMB) in order to enable safe spin down and reduce secondary damage. Especially for high speed applications like flywheels with high rotor inertia, the requirements towards the load capacity and service life of the BB is comparably high. For a special type of flywheel with exceptionally high speeds in the BB interface, a planetary BB system is presented. The planetary BB consists of multiple bearing units placed circumferentially around the stator. Its elastic properties are described as well as a contact damping approach. For cost efficient BB investigation, a scaled test rig is introduced and a parametric study of different delivitations simulations is done. Several quantification methods to evaluate severity, bearing loads and lifetime utilization during BB are presented and applied to the simulations. The applicability of the planetary BB to vertical high speed rotors is confirmed by the simulation data and bearing element selection is affirmed. The results of the quantification methodologies show specific correlation to initial conditions and parameters like unbalance and in particular contact friction coefficient.
BibTeX:
@inproceedings{ISMB15_110,
  author = {Lukas Quurck},
  title = {Planetary Backup Bearings for High Speed Applications and Service Life Estimation Methodology},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_110.pdf}
}
2016 Yang, G., Shi, Z., Zhao, J., Zhou, Y., Liu, X., Mo, N. and Sun, Z. Research and Experiment of Auxiliary Bearing for Helium Circulator of HTR-PM Proceedings of ISMB15  
Abstract: The research and application of the unlubricated auxiliary bearing is very important in certain special circumstances, such as in the nuclear power station, aeroplane engine and so on. Active magnetic bearing (AMB) is replacing ordinary mechanical bearings as the perfect supporting scheme for the helium circulator of high-temperature gas-cooled reactor-pebble bed module (HTR-PM) of China. Because it has several advantages: free of contact, no lubrication and controllability very well, etc. The auxiliary bearing is used to support the circulator rotor when the AMB fails to work, but oil or grease can’t be applied for this auxiliary bearing. And it must support the dropping rotor and bear the great impact force and friction heat. The design of the auxiliary bearing is one of the challenging problems in the whole system. A new design plan of auxiliary bearing is proposed in this paper. This auxiliary bearing is composed of angular contact ceramic ball bearing designed by special technology. Two pairs of bearing will be distributed on both ends of the rotor. Each pair of bearing arrangement is face to face. The rotor’s length of helium circulator of HTR-PM is about 3.3 m, its weight is about 4000 kg and the rotating speed is 4000 r/min. It is difficult to analyze the falling course of the rotor. The preliminary analysis and experiment of the dropping rotor was done in this paper. The auxiliary bearing’s life will be evaluated. And the buffer shim is also studied to reduce the impact force by simulation in this paper. The scheme of auxiliary bearing and the experimental results offer the important base for this new auxiliary bearing style, and offer the protector design of the helium circulator with AMB for HTR-PM.
BibTeX:
@inproceedings{ISMB15_111,
  author = {Guojun Yang and Zhengang Shi and Jingjing Zhao and Yan Zhou and Xingnan Liu and Ni Mo and Zhe Sun},
  title = {Research and Experiment of Auxiliary Bearing for Helium Circulator of HTR-PM},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_111.pdf}
}
2016 Lv, M., Wang, Z. and Wang, Y. A performance analysis model with thermodynamic and superficial effects of the auxiliary bearings in AMB systems Proceedings of ISMB15  
Abstract: The touchdown bearing is one of the essential parts of AMB. When the magnetic bearing fails, touchdown events will occur and the rub-impact between the rotor and the touchdown bearings will happen. In practice, the analysis of the process is complex as it is coupled with dynamics, superficial and thermal effects. A simulation model in which the kinetic equations of the rotor and the bearing are derived from Lagrange’s equations and the drag torque of the ball bearings is calculated by Palmgren’s empirical formula has been established. The simulation results show that the orbit response of the pendulum vibration appears when the rotating speeds and the friction coefficients are low, while the orbit response of the backward whirl appears when the rotating speeds and the friction coefficients are high. The critical whirl speed has been illustrated for the guidance of the safe landing of the rotor. The maximum contact forces and heat peak power have also been calculated. The maximum contact forces keep almost constant when both the rotating speeds and the friction coefficients are low. It increases with the growth of the rotating speed and the friction coefficient with high rotating speeds, high friction coefficients or both. The peak thermal power increases with the incline of the rotating speeds and friction coefficients.
BibTeX:
@inproceedings{ISMB15_112,
  author = {Mindong Lv and Zixi Wang and Yuming Wang},
  title = {A performance analysis model with thermodynamic and superficial effects of the auxiliary bearings in AMB systems},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_112.pdf}
}
2016 Beatty, M.S. and Mahfoud, J. Control of Flexible Rotor by Using Electromagnetic Actuators Optimization of the Fuzzy Controller Gains Proceedings of ISMB15  
Abstract: The aim is to set an optimization procedure for the determination of a fuzzy based controller gains. The objective function is defined as a combination of the maximum current, the displacements measured and the settling time. Two fuzzy based controllers were developed, the first has displacement and velocity as inputs (a fuzzy Proportional Derivative) and the second utilizes inputs expressed in polar coordinates. Its originality is that it manages two significant physical quantities, namely tangential and radial velocities, associated with steady state and transient behaviours respectively. The gains of the fuzzy PD controllers were determined by using optimization procedures that takes into account the mechanical behavior and the energy consumption. The gains (for the three controllers) were first determined by using numerical simulations, and then implemented for experimental testing. An additional tuning (in-situ) was necessary for the PD controller. The performances of the two fuzzy based controllers were compared to a PD controller experimentally from mechanical and energy consumption points of view. The three controllers were efficient with a better behavior for the fuzzy based controllers for run up conditions. The optimization procedures are efficient and easy to implement in the case of PD fuzzy controllers, and must be enhanced to consider rules with different output, as in the case of polar fuzzy controller.
BibTeX:
@inproceedings{ISMB15_113,
  author = {Michael Soler Beatty and Jarir Mahfoud},
  title = {Control of Flexible Rotor by Using Electromagnetic Actuators Optimization of the Fuzzy Controller Gains},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_113.pdf}
}
2016 Levy, R. and Arogeti, S. Simple and Effective Dynamic Model Identification Procedure of Magnetically Suspended Flexible Rotor Systems Proceedings of ISMB15  
Abstract: Advanced controllers for magnetically supported flexible rotors require an accurate model of the system dynamics. Standard identification procedures can generate accurate models, but in general, do not provide the specific value of physical parameters, needed in some applications such as inertial centering. Moreover, some of these identi- fication techniques are not trivial for implementation and may require special signal-processing skills, nonlinear optimization, etc. In the robotics community, a well-established and widely recognized identification procedure can be found for fully-actuated industrial robots. This paper suggests a procedure that makes this identification technique applicable, also to magnetically supported flexible rotors, which are under-actuated systems. The origi- nal maximum-likelihood based procedure is modified by introducing both statistics and weights to the covariance matrix of input forces. The procedure is exemplified through numerical simulations, considering an 8-DoF flexible rotor system. The results show that although the system is under-actuated, the modified identification procedure provides satisfactory results, in the sense that all rotor parameters are accurately identified, including the parame- ters of mass imbalance.
BibTeX:
@inproceedings{ISMB15_114,
  author = {Rami Levy and Shai Arogeti},
  title = {Simple and Effective Dynamic Model Identification Procedure of Magnetically Suspended Flexible Rotor Systems},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_114.pdf}
}
2016 Ariga, Y. and Sakai, Y. Nonlinear Control Type Magnetic Bearing for Adding Damping Force to Existing Rotor Proceedings of ISMB15  
Abstract: This paper proposes a nonlinear control method of magnetic bearings for adding the desired damping force to an existing rotor supported by passive magnetic bearings (PMBs) or gas bearings. PMBs composed only of permanent magnets do not require a control circuit. Therefore, PMBs can be economically manufactured. However, the vibrations cannot be suppressed because PMBs cannot generate damping force. Therefore, studies have been conducted on hybridized magnetic bearings. However, hybridized magnetic bearings have a disadvantage in that they are complicated and expensive. Gas bearings can generate excellent support force and damping force during high-speed rotation. However, it is difficult to dampen certain vibrations such as whirl vibration. Therefore, a method combining gas bearings and active magnetic bearings (AMBs) was considered in order to dampen such vibrations. Because the support rigidity of the AMBs are applied, the dynamics is significantly changed as compared with rotors supported only by the gas bearings. Moreover, because sufficient stiffness can be obtained from the gas bearings, it is useless to add stiffness through the magnetic bearings. To solve the above problems, we propose the use of the AMBs only for the generation of damping force. When using a general linear control, it is necessary to supply the bias current to the AMBs. However, it adversely affects the support stiffness of the rotor because a negative stiffness is generated by the bias current. We have previously proposed a control method with unnecessary bias current through nonlinear control of the AMB, and applied this method to actual equipment. However, this method involved the generation of both support force and damping force. Here, we focus on generating only damping force. This method is verified through the simulation.
BibTeX:
@inproceedings{ISMB15_115,
  author = {Yuichi Ariga and Yasumitsu Sakai},
  title = {Nonlinear Control Type Magnetic Bearing for Adding Damping Force to Existing Rotor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_115.pdf}
}
2016 Lusty, C. and Keogh, P. Vibration reduction in a hollow-shaft rotor using flexibly-mounted internal-stator magnetic bearings Proceedings of ISMB15  
Abstract: A topology composed of a hollow-shaft rotor on rolling element bearings coupled with internal-stator magnetic bearings mounted on independently supported flexible shafts is considered for the purposes of vibration reduc- tion. Details of a bespoke test rig constructed to assess this topology are presented. The rig makes use of custom-designed internal-stator magnetic bearings fabricated from Soft Magnetic Composite material. Results from standard numerical analysis of the rig are given to demonstrate the expected behaviour of the system, with a particular focus on its potential to reduce synchronous vibration seen while passing critical speeds. These be- haviours are then confirmed via both impulse frequency response tests and rotating run-down tests. These results show that the proposed topology can be used effectively to alter the system vibration behaviour.
BibTeX:
@inproceedings{ISMB15_116,
  author = {Chris Lusty and Patrick Keogh},
  title = {Vibration reduction in a hollow-shaft rotor using flexibly-mounted internal-stator magnetic bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_116.pdf}
}
2016 Mao, C., Chen, L. and Zhu, C. Vibration control for active magnetic bearing high-speed flywheel-rotor system with inverse system method and two-degree-of-freedom PID control Proceedings of ISMB15  
Abstract: In the high-speed flywheel energy storage system, the high ratio of the polar to transverse mass moments of inertia of the flywheel rotor and the high operating speed will result in a significant coupled effect. It is not easy to apply normal PID control method in active magnetic bearing (AMB) high-speed flywheel-rotor system for its coupling characteristic. In order to improve the coupled performances of this system, a control strategy that combines inverse system method and two-degree-of-freedom PID control is proposed in this paper. After introducing the model of an AMB high-speed flywheel-rotor system, the decoupling and interference rejection capabilities are simulated. The results show that with by means of the control strategy proposed, the system with strong gyroscopic effect in the high rotating speed region is decoupled and both the static and dynamic performances are greatly improved. An experiment has been done to verify the feasibility of the control strategy proposed.
BibTeX:
@inproceedings{ISMB15_117,
  author = {Chuan Mao and Liangliang Chen and Changsheng Zhu},
  title = {Vibration control for active magnetic bearing high-speed flywheel-rotor system with inverse system method and two-degree-of-freedom PID control},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_117.pdf}
}
2016 Beneden, M.V., Kluyskens, V. and Dehez, B. Comparison between optimized topologies of permanent magnet thrust bearings with back-iron Proceedings of ISMB15  
Abstract: This paper deals with the optimization and the comparison of passive magnetic thrust bearings made up of radial stacks of permanent magnet rings. Various topologies are considered, depending on the polarization direction of the permanent magnet rings and the presence of back-iron. The coulombian approach and the method of image charges are used to determine the load capacity of topologies with back-iron. On this basis each topology is optimized in order to minimize the permanent magnet volume for a fixed load capacity, airgap thickness and remanent flux density. Varying these parameters, scaling laws of the optimum permanent magnet ring dimensions are derived to allow fast sizing and comparison of the topologies. The latter highlights that the topology with Halbach configuration and back-iron is the most performant, but that the topology with axial polarization is almost as good.
BibTeX:
@inproceedings{ISMB15_118,
  author = {Maxence Van Beneden and Virginie Kluyskens and Bruno Dehez},
  title = {Comparison between optimized topologies of permanent magnet thrust bearings with back-iron},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_118.pdf}
}
2016 Santiago, J.D., Oliveira, J.G., Rodriguez, E., Sotelo, G.G. and Hedlund, M. Eigen frequency and damping in a passive magnetic bearing system Proceedings of ISMB15  
Abstract: A complete passive magnetic bearing system, consisting in a Permanent Magnet radial bearing and a Superconductive Magnetic Bearing has been simulated and constructed. The forces in both types of magnetic bearings are not linear. The non-linear behavior has been implemented in a FEM model and compared with linear models. A spin down test has been conducted to the built system and the Eigen frequencies have been recorded. The Eigen frequencies calculated with and without the non-linear behavior implemented in the model are very similar.
BibTeX:
@inproceedings{ISMB15_119,
  author = {Juan De Santiago and Janaina G. Oliveira and Elkin Rodriguez and Guilherme G. Sotelo and Magnus Hedlund},
  title = {Eigen frequency and damping in a passive magnetic bearing system},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_119.pdf}
}
2016 Annasiwaththa, B.I. and Oka, K. Zero Power Levitation Control of a Magnetically Levitated Linear Slider Platform with Non-Contact Power Supply Proceedings of ISMB15  
Abstract: A magnetically levitated linear slider platform with a non-contact power supply method is presented in this paper. The non-contact power supply was achieved using an open end generator with a plastic core. The objectives of this paper is to present FEM analysis of the open end generator and initial observations from the experimental prototype. The rotor of the open end generator was mounted on the stationary structure of the system and the rotor includes 6 magnetic pole pairs mounted on the surface of the rotor. The levitated platform was constructed by mounting four hybrid electromagnets on four corners of a single rigid rectangular steel plate. The cogging torques introduced by the open end generator on the levitated platform was investigated using FEM method and the results presented. Levitation of the platform was achieved while open end generator is producing electrical power. The performance of the levitated platform with the open end generator was experimentally measured and presented. The rotor of the open end generator was rotated at 1000rpm. The amount of total root mean square electrical power dissipated through 19Ω load resistors by an open end generator with plastic core was 35W. The levitated platform achieved less than 0.25W power consumption per hybrid electromagnet during steady state operation. Estimated power consumption by the sensors and the electronic control boards used in the experimental platform was approximately 15W. The results suggest that the open end generator can produce sufficient amount of power to support platform levitation and control.
BibTeX:
@inproceedings{ISMB15_12,
  author = {Buddhika Imantha Annasiwaththa and Koichi Oka},
  title = {Zero Power Levitation Control of a Magnetically Levitated Linear Slider Platform with Non-Contact Power Supply},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_12.pdf}
}
2016 Kanda, K., Sasaki, H., Sasaki, M. and Sugiura, T. Numerical Verification of Amplitude Reduction of a Rotor Supported by a Superconducting Magnetic Bearing Utilizing Internal Resonance Proceedings of ISMB15  
Abstract: Superconducting magnetic bearings (SMBs) have some advantages compared with mechanical bearings. However, whirling amplitude of a rotor supported by SMB tends to be large near the critical rotational speed because of their low damping. Furthermore, complicated phenomena of dynamics can be generated due to nonlinearity of the levitation force. Therefore it is necessary to reduce the amplitude by considering the effect of the nonlinearity on dynamics during passing through the critical speed in applications. In this paper, we investigated resonant amplitude reduction of a rotor supported by two movable superconducting bulks (SCs). For this purpose, we first introduced an analytical model consisting of a rotating permanent magnet and the unfixed SCs that can move around the rotor and are connected with springs. We evaluated electromagnetic force by the advanced mirror image method and derived governing equations of the rotor at an arbitrary rotational speed. From the nondimensionalized equations of motion, we predicted that internal resonance between whirling of the rotor and swinging of the SCs can occur if the ratio among the natural frequencies of those motions is an integer ratio. We also performed numerical calculation of equations of motion. The numerical results show that internal resonance can occur at around the critical speed and that as a result reduction of the resonant whirling amplitude can be achieved by the swinging SCs at around the critical speed.
BibTeX:
@inproceedings{ISMB15_120,
  author = {Koki Kanda and Hiromu Sasaki and Masahiko Sasaki and Toshihiko Sugiura},
  title = {Numerical Verification of Amplitude Reduction of a Rotor Supported by a Superconducting Magnetic Bearing Utilizing Internal Resonance},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_120.pdf}
}
2016 Berger, A., Sparing, M., Berger, D., Fuchs, G., Hossain, M., Abdkader, A., Cherif, C. and Schultz, L. Hysteresis in an axial rotating SMB used in the ring spinning process Proceedings of ISMB15  
Abstract: Superconducting magnetic bearings are passive stable magnetic levitating bearings which only need a material depending cryogenic temperature for their operation. The application of a rotating superconducting magnetic bearing (SMB) with high rotational speed in a ring spinning machine replaces the traditional, friction afflicted ring-traveler twist element. Ring spinning is the most common process to produce short stable yarn in textile industry. The SMB twist element significantly reduces the productivity limiting friction heat in the spinning process and thus the process speed will be increased from commonly 25000 rpm up to 50000 rpm. In this application melt textured YBa 2 Cu 3 O 7-x (YBCO) is used as superconductor and NdFeB as permanent magnet (PM). The PM ring rotates driven by the yarn and thereby imparts twist in it. The yarn force on the PM is an eccentric acting point force which leads to a tilt of the PM ring in the position to the superconductor ring. In combination with high rotational speed this tilt leads to a significant heat input in the superconductor due to hysteresis.
BibTeX:
@inproceedings{ISMB15_121,
  author = {Anne Berger and Maria Sparing and Dietmar Berger and Guenter Fuchs and Mahmud Hossain and Anwar Abdkader and Chokri Cherif and Ludwig Schultz},
  title = {Hysteresis in an axial rotating SMB used in the ring spinning process},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_121.pdf}
}
2016 Minoda, A., Komori, M., Nemoto, K., Asami, K.-I. and Sakai, N. Trial of Large Gap Using Superconducting Magnetic Suspension System Proceedings of ISMB15  
Abstract: Superconducting technique is applied to a suspension system. Persistent current in superconducting coil and control current in copper coil are used for suspending object and controlling object, respectively. The system is composed of a superconducting coil, a copper coil, a suspended object, a photo sensor, a PID controller, and power amplifiers. In this paper, basic study on superconducting coil and solenoid coil, and the dynamic characteristics of the suspended object are performed. As a result, it is found that the suspended object continues to levitate at a distance 43mm for 15s. This may be the first trial that superconducting coil is used for magnetic suspension.
BibTeX:
@inproceedings{ISMB15_122,
  author = {Akira Minoda and Mochimitsu Komori and Kaoru Nemoto and Ken-Ichi Asami and Nobuo Sakai},
  title = {Trial of Large Gap Using Superconducting Magnetic Suspension System},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_122.pdf}
}
2016 Defoy, B., Lepine, X.D. and Broussard, L. Numerical and experimental assessment of a large industrial thrust bearing Proceedings of ISMB15  
Abstract: Nowadays, Active Magnetic Bearings (AMB) are widely utilized in different industrial applications. Several applications have been successfully implemented in the field of Turbomachinery especially for large centrifugal compressors. These machines are subjected to high axial transient loads due to process operations. Considered simpler than radial bearings, the thrust bearing optimization has been largely neglected. Consequently, the thrust bearing suffers from sizing difficulties that lead to bad overall system optimization. Thrust behavior exhibits several peculiarities mainly due to the specific arrangement of thrust actuator made with a solid disk instead of laminated sheets for radial bearings. The work presented here aims to improve the prediction of thrust dynamic in order to better size this component and ensure smooth operation of machinery. The paper describes the complete analysis of a 25kN thrust bearing. The study is divided in two sections, first the actuator analysis and then the dynamic behavior of the complete system. The thrust bearing electromagnetic design was developed with the aid of Finite Element Analysis (FEA). The thrust bearing performance calculations are disclosed in this paper and compared with those of an actuator characterization test bench. Later, the thrust actuator is mounted on a complete AMB experimental set-up, equipped with a 200 kg rotor on two radial magnetic bearings. The test rig is equipped with a contactless axial actuator that enables the excitation of the rotor with different axial force amplitudes and ramps. The first FEA and experimental results are used to feed a simplified model of the complete thrust bearing. The experimental results are compared with numerical ones. The different phenomena observed are discussed and the system limitations are highlighted. This study enables better understanding of the behavior of large thrust bearings. In addition, the work realized help to predict and optimize thrust bearing response for each machine.
BibTeX:
@inproceedings{ISMB15_13,
  author = {Benjamin Defoy and Xavier De Lepine and Lionel Broussard},
  title = {Numerical and experimental assessment of a large industrial thrust bearing},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_13.pdf}
}
2016 Lorenz, F. and Werner, R. Design of a Mobile Flywheel Energy Storage driven by a Switched Reluctance Machine Proceedings of ISMB15  
Abstract: The rising number of hybrid and fully electrical driven cars requires more powerful short term energy storages to recover the breaking energy, especially in urban traffic. This paper presents a mobile flywheel energy storage system (FESS) designed for the use in mobile applications like passenger cars. The system is equipped with a carbon fiber composite flywheel connected to two switched reluctance machines which both can operate as motor and generator. The storage capacity is 190Wh at an overall weight of 64kg. The peak power of the system is 24kW. The construction of the flywheel will be outlined considering a stress distribution up to 30 000rpm as well as rotordynamic concerns including the bearing concept. The system carries hybrid super precision roller bearings in a paired (tandem) configuration equipped with adjustable preloading and direct water cooling. Switched reluctance machines (SRMs) show great advantages in flywheel applications such as wide speed range, high reliability, and a robust rotor structure. The modelling process for the driving SRMs will be presented including the simulation workflow as well as results for key operation points.
BibTeX:
@inproceedings{ISMB15_14,
  author = {Fabian Lorenz and Ralf Werner},
  title = {Design of a Mobile Flywheel Energy Storage driven by a Switched Reluctance Machine},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_14.pdf}
}
2016 Guo, Z., Zhou, G., Shultz, R.R. and Qian, M. Design and Qualification Testing of Active Magnetic Bearings for High-Temperature Gas-Cooled Reactors Proceedings of ISMB15  
Abstract: Active magnetic bearings have been utilized in all recent high-temperature helium-cooled reactor designs as the only mature dry bearing technology to provide high reliability and availability of operations for these highly demanding applications. High reliability and availability is accomplished through proper design of the magnetic bearings, auxiliary bearings, and control and monitoring systems, as well as the exploitation of provisions for remote observability and diagnostics. Designing magnetic bearings into HTR fluid machines such as primary helium circulators and fuel ball blowers eliminates bearing lubricant contamination and also eliminates the ancillary equipment associated with the sealing systems for bearing lubricant. Recently a helium circulator and a fuel ball blower supported with magnetic bearings were tested separately and fully qualified for HTR plant operation. The magnetic bearings and auxiliary bearing systems were fully tested in a helium environment inside the machines. The current paper addresses the unique attributes in the design of magnetic bearing systems and the qualification testing performed for the HTR-PM fuel ball blower.
BibTeX:
@inproceedings{ISMB15_15,
  author = {Zenglin Guo and Guohui Zhou and Richard R. Shultz and Minlong Qian},
  title = {Design and Qualification Testing of Active Magnetic Bearings for High-Temperature Gas-Cooled Reactors},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_15.pdf}
}
2016 Lauridsen, J.S. and Santos, I.F. Design of Robust AMB Controllers for Rotors Subjected to Varying and Uncertain Seal Forces Proceedings of ISMB15  
Abstract: This paper demonstrates the design and simulation results of model based controllers for AMB systems, subjected to uncertain and changing dynamic seal forces. Specifically, a turbocharger with a hole-pattern seal mounted across the balance piston is considered. The dynamic forces of the seal, which are dependent on the operational condi- tions, have a significant effect on the overall system dynamics. Furthermore, these forces are considered uncertain. The nominal and the uncertainty representation of the seal model are established using results from conventional modelling approaches, i.e. CFD and Bulkflow, and experimental results. Three controllers are synthesized: I) An H-inf controller based on nominal plant representation, II) A µ controller, designed to be robust against uncertainties in the dynamic seal model and III) a Linear Parameter Varying (LPV) controller, designed to provide a unified performance over a large operational speed range using the operational speed as the scheduling parameter.
BibTeX:
@inproceedings{ISMB15_16,
  author = {Jonas Skjoedt Lauridsen and Ilmar Ferreira Santos},
  title = {Design of Robust AMB Controllers for Rotors Subjected to Varying and Uncertain Seal Forces},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_16.pdf}
}
2016 Li, L., Duesterhaupt, S. and Worlitz, F. Experimental Verification of Adaptive Control in Active Magnetic Bearings Proceedings of ISMB15  
Abstract: The strong nonlinearity and uncertainty of the active magnetic bearing (AMB) makes the controller difficult to design. In many applications the design of the control is performed under the assumption that all system parameters are exactly measured in advance and do not change during operation. For these plants, it is sufficient to design a robust controller for a limited range of operation (Peter Wurmsdobler, 1997). In high performance machinery, however, a change in operation condition may easily occur. This event may lead to destabilizing finally. This paper presents a concept of adaptive control in combination with KALMAN filter, in order to guarantee the optimal control behavior in various operating condition and a desired performance for a wide range of operation. This paper extends this tropic from the former experiment to a test facility with strong nonlinearity / uncertainty and draws a brief comparison to a fixed control design.
BibTeX:
@inproceedings{ISMB15_17,
  author = {Li Li and Stephan Duesterhaupt and Frank Worlitz},
  title = {Experimental Verification of Adaptive Control in Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_17.pdf}
}
2016 Tomono, H., Fujisaki, H., Watanabe, T. and Seto, K. Improvement of Active Magnetic Bearing system using Jerk Feedback Controller for an Elastic Rotor Proceedings of ISMB15  
Abstract: This paper presents an integrated control system performing levitation and vibration suppression for a magnetic bearing (AMB) supporting elastic rotor. Stable levitation of the elastic rotor is achieved by using PD controller. However, there is a problem with the 2nd mode of the elastic rotor appeared notably. We are aiming to introduce jerk feedback control term for this problem. In previous studies, jerk feedback controller is applied that posses difficulty in tuning. In this study, location of AMBs and the shape of the rotor are modified to solve problem as controllability and observability. Moreover, we introduce acceleration feedback controller coupling to PD controller and phase lead compensator in series. The effect of presented controller is verified by experiment.
BibTeX:
@inproceedings{ISMB15_18,
  author = {Hirokazu Tomono and Hiroyuki Fujisaki and Toru Watanabe and Kazuto Seto},
  title = {Improvement of Active Magnetic Bearing system using Jerk Feedback Controller for an Elastic Rotor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_18.pdf}
}
2016 Di, L., Chen, C.Y. and Lin, C.H. Characteristic Model Based All-Coefficient Adaptive Control of a High-Speed Desorption Pump Supported by AMBs Proceedings of ISMB15  
Abstract: Active magnetic beatings (AMBs) have been increasingly adopted in industries that involve high-speed rotating machinery and feedback control design is one of the essential problems in AMB systems. In this paper, we report on the development of the characteristic model based all-coefficient adaptive control (ACAC) method to a high- speed desorption pump supported by AMBs. This control method does not require the actual system model and is able to deliver strong performance and robustness, as validated in many successful engineering applications. The desorption pump studied in this paper is designed to operate at a speed of 60,000 rpm, which indicates that a potentially large unbalance force might be introduced to drive the AMB system into instability. Meanwhile, the rising speed range is wider than typical machines so that the natural modes can split more significantly due to the gyroscopic effect, which will introduce strong uncertainties. Therefore, a successful controller must guarantee the closed-loop stability and minimize the vibration during the speed increase as well as at the operational speed. The simulation results have demonstrated the proposed ACAC method is capable of achieving the control requirements and the controller will be implemented on the test rig for experimental validations.
BibTeX:
@inproceedings{ISMB15_19,
  author = {Long Di and Chao Yun Chen and Chung Hsien Lin},
  title = {Characteristic Model Based All-Coefficient Adaptive Control of a High-Speed Desorption Pump Supported by AMBs},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_19.pdf}
}
2016 Sugino, M., Miyazaki, Y., Nagashima, K., Ogata, M., Yamashita, T. and Matsuoka, T. The development of the flywheel energy storage system applying the high temperature superconducting magnetic bearing (second report) - The development and the performance evaluation examination of the SMB for the FESS demonstration machine Proceedings of ISMB15  
Abstract: A new type of bearingless motor has been developed. The feature of this bearingless motor is no use of permanent magnets. The rotor is magnetized by a current of a non-contact power supply, which consists of a bridge rectifier circuit and coils. Levitation is achieved through attractive forces generated by inclinations on the edges of the rotor and the stator. In the previous study, levitation of a prototype system could not be achieved. It was posited that the inclination of edges decreases restitutive force, which is used to control the tilting motion of the rotor. In this paper, the impact of the inclination of the edges on the decrease of restitutive force was investigated and confirmed by 3D-FEM analysis. Additionally, levitation of the prototype system was investigated by simulating the displacement of the rotor with both linear and non-linear rotor models. Finally, the control principle was changed according to findings of this study and the controllable range of the rotor was calculated.
BibTeX:
@inproceedings{ISMB15_2,
  author = {Motohiko Sugino and Yoshiki Miyazaki and Ken Nagashima and Masafumi Ogata and Tomohisa Yamashita and Taro Matsuoka},
  title = {The development of the flywheel energy storage system applying the high temperature superconducting magnetic bearing (second report) - The development and the performance evaluation examination of the SMB for the FESS demonstration machine},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_2.pdf}
}
2016 Jastrzebski, R.P., Jaatinen, P. and Chiba, A. Efficiency of buried permanent magnet type 5kW and 50kW high-speed bearingless motors with 4-pole motor windings and 2-pole suspension windings Proceedings of ISMB15  
Abstract: This work focuses on loss prediction for varying operation conditions of the high-speed buried-type interior permanent magnet (IPM) bearingless motors. The investigated motors are 5 kW and 50 kW units configured as twin motor sets, which provide radial suspension and motoring in 5 degrees of freedom levitated rotor systems with the maximum speed of 30000 r/min. The maximum output power of studied rotor systems is 10 kW and 100kW, respectively. Additionally, the power factors of motor and suspension windings as well as inductance maps for various operating conditions are studied. The magnetic field 2-dimentional transient section analysis and time stepping are applied. The selected results are compared with the measured values. In the loss calculation various rotor and stator iron losses, resistive losses, windage losses and additional losses are taken into account. Efficiency maps and power factor estimation are valuable for application of electrical machines. These studies have been performed using various methods for classical motors and generators but are uncommon for bearingless motors working with different loading conditions. The comprehensive efficiency map prediction of the high-speed IPM bearingless motors for different suspension loading is presented for the first time. The variations of motor inductances for different rotor angles and current amplitudes are derived. The differences in results between the machines with the same geometry but different power are discussed.
BibTeX:
@inproceedings{ISMB15_20,
  author = {Rafal Piotr Jastrzebski and Pekko Jaatinen and Akira Chiba},
  title = {Efficiency of buried permanent magnet type 5kW and 50kW high-speed bearingless motors with 4-pole motor windings and 2-pole suspension windings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_20.pdf}
}
2016 Lopes, J.S.B., Fernandes, J.D., Souza, F.E., Santos, L.P., Paiva, J.A.D. and Salazar, A.O. Using feed-forward back propagation for Rotor Flux Estimation of a Bearingless Induction Motor applied in the Speed Vector Control Proceedings of ISMB15  
Abstract: This study presents the problem of rotor flux orientation control of induction-type bearingless motor. The key of this solution is the estimation of rotor flux. The neural network is able to estimate accurately the rotor flux magnitude or position. The bearingless induction motor model is used to obtain the training data and the learning technique used was investigated by computer simulation. The bearingless induction motor model characteristics were 3,75 kW, two pole-pair, 60 Hz, air-gap length 0.2 mm cage rotor is based on an input-output model. The adopted model have balanced three-phase currents and despised the viscous friction of the bearings. The software environment used for this simulation was MATLAB® R2010a. The motor equation were solved by using step- by-step numerical integration with an integration 10 -5 s. The simulated results showed good performance. It was used a simulator based on the finite elements method for acquiring flux density for Bearingless Induction Motor model. This paper aims at compensating possible parametric variations of the motor caused by agents such as temperature or nucleus saturation and that neural network flux estimation may be a feasible alternative to other flux estimation methods. The results obtained by simulation confirm the effectiveness of the method.
BibTeX:
@inproceedings{ISMB15_21,
  author = {Jose Soares Batista Lopes and Jefferson Dollan Fernandes and Francisco Elvis Souza and Luciano Pereira Santos and Jose Alvaro De Paiva and Andres Ortiz Salazar},
  title = {Using feed-forward back propagation for Rotor Flux Estimation of a Bearingless Induction Motor applied in the Speed Vector Control},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_21.pdf}
}
2016 Ueno, S., Otani, R. and Jiang, C. Unbalance Compensation for Lorentz-force-type Self-Bearing Motor Proceedings of ISMB15  
Abstract: A self-bearing motor is a combination of magnetic bearings and an electric motor, and many types of self-bearing motors have been proposed and developed. A Lorentz-force-type self-bearing motor consists of distributed wind- ings as a stator, and permanent magnets as a rotor. This motor does not have a stator core and slots, then, the structure of the motor becomes simple, and it allows miniaturization and cost reduction. However, the manufac- turing error of the distributed windings is not small, hence, the bearing force is affected by the rotating position of the rotor. This causes the rotor vibration, rotating losses, large stator current, and so on. To solve this problem, this paper introduces unbalance compensation for the position control of the rotor. The vibration synchronized with the rotation can be canceled by the integral feedback on the rotor coordinate system, and then, it is possible to reduce the vibration or motor current. The experimental results show that the unbalance compensation technique is effective for reducing motor currents.
BibTeX:
@inproceedings{ISMB15_22,
  author = {Satoshi Ueno and Ryosuke Otani and Changan Jiang},
  title = {Unbalance Compensation for Lorentz-force-type Self-Bearing Motor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_22.pdf}
}
2016 Ooshima, M. and Gomi, Y. Evaluation of Motor Losses and Efficiency in a d-q Axis Current Control Bearingless Motor Proceedings of ISMB15  
Abstract: This paper presents the motor characteristic, for example, motor efficiency and losses, of a d-q axis current control bearingless motor, which has been proposed by the authors. In the d-q axis current control bearingless motor, both the motor drive and magnetic suspension can be successfully performed by one kind of stator winding. The torque and magnetic suspension characteristics have been found and the superiority of them is recognized. In this paper, the motor characteristic is derived by Finite Element (FE) analysis using a simulation software, and furthermore compared with those of the computed results of the conventional bearingless motors, which two kinds of windings for motor drive and magnetic suspension are wound in a stator core. Three types of the conventional bearingless motor with n-pole motor winding and (n +- 2)-pole suspension winding are taken up in this paper. The stator and rotor iron losses, eddy current loss in the rotor permanent magnets are simulated, respectively. The motor efficiency is also estimated based on the computed output power and motor losses by FE analysis. The efficiency and loss in each part are compared with those of the conventional bearingless motors, respectively, and it is discussed in detail by what the difference of losses between the bearingless motor types is mainly caused.
BibTeX:
@inproceedings{ISMB15_23,
  author = {Masahide Ooshima and Yuto Gomi},
  title = {Evaluation of Motor Losses and Efficiency in a d-q Axis Current Control Bearingless Motor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_23.pdf}
}
2016 Park, C.H. and Park, J.Y. Design and Experiment of 300 HP Class Turbo Compressor with Hybrid Magnetic Bearings Proceedings of ISMB15  
Abstract: High-capacity and high-efficiency turbomachinery, such as turbo blowers and turbo compressors, have been developed recently. In order to keep up with these trends, magnetic bearings are being increasingly applied to turbomachinery instead of air foil bearings. In this study, hybrid magnetic bearings are applied to a 300-HP-class turbo compressor, and a no-load test and full load test were performed to evaluate the performance of the designed magnetic bearings. The rotor speed could be increased up to 51,000 rpm in the no-load test, and 45,000 rpm in the full load test. The results indicated a low level of rotor vibration and stable performance of the magnetic bearings in both the tests. Owing to the cooling system that uses water and air, the problem of thermal expansion of the rotor in the axial direction. could be avoided. The estimated aerodynamic thrust force is approximately 407 N at 45,000 rpm under the full load condition; thus, it is verified that the thrust magnetic bearings have sufficient load capacity.
BibTeX:
@inproceedings{ISMB15_24,
  author = {Cheol Hoon Park and Jun Young Park},
  title = {Design and Experiment of 300 HP Class Turbo Compressor with Hybrid Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_24.pdf}
}
2016 Jayawant, R. and Masala, A. Design and Commissioning of a 3.3 MW Motor-Driven Compressor Fully Supported on Active Magnetic Bearings Proceedings of ISMB15  
Abstract: This paper describes the design and commissioning of active magnetic bearings (AMBs) for a 3.3 MW motor- driven compressor. The total string comprises a motor coupled (via a flexible coupling) to a compressor, with the two machines mounted in separate casings. The design of the compressor AMBs, in particular the rotordynamic design, is described together with the commissioning experience for both the compressor and the coupled string. The use of third-generation Automated Commissioning tools in the initial setup and the dynamic tuning of the machine is described. These tools were deployed remotely and the impact of this remote mode of commissioning on the required work methods, including the impact of variable performance in Internet connectivity and the tools required for communication across large differences in time zones, is examined. Particular issues encountered during the commissioning, triggered by use of close clearance seals, are discussed; these include impact on the use of the Automated Commissioning tools, impact on the vibration performance of the machine (with solutions to overcome these problems), and impact of stiction in the seals on the rotordynamic measurements. The results of the vibration measurements and sensitivity function measurements for the tuned machine are presented.
BibTeX:
@inproceedings{ISMB15_25,
  author = {Richard Jayawant and Andrea Masala},
  title = {Design and Commissioning of a 3.3 MW Motor-Driven Compressor Fully Supported on Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_25.pdf}
}
2016 Aeschlimann, B., Hubatka, M., Peter, M.E., Stettler, R. and Housseini, R. Commissioning of Off-Shore Gas Compressor with 9-Axes Magnetic Bearing System: Controller Design Proceedings of ISMB15  
Abstract: This paper presents the system model, model validation, controller design and test measurements for an industrial 9-axes oil-free integrated motor-compressor (tandem HOFIM(TM)) manufactured by MAN Diesel & Turbo (MAN) to be installed off-shore on an oil rig. The magnetic bearing controller of such machines must be designed with high robustness due to large expected uncertainties in the control plant. In addition, the magnetic bearings must have a high force slew rate, and thus a high dynamic controller, since compressor surge that causes high alternating process forces cannot always be avoided in field operation. These two requirements are conflicting and it is a difficult task to find a good compromise. This paper presents an application of robust controller design and a solution to this problem: the LQG/LTR method, well described in literature, is applied for the design of the position controller. Using the proposed method, the compressor was successfully commissioned at the MAN test facility and all specifications were met.
BibTeX:
@inproceedings{ISMB15_26,
  author = {Beat Aeschlimann and Michael Hubatka and Michael Ernst Peter and Robert Stettler and Reza Housseini},
  title = {Commissioning of Off-Shore Gas Compressor with 9-Axes Magnetic Bearing System: Controller Design},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_26.pdf}
}
2016 Mushi, S., Nichols, B., Dimond, T., Allaire, P., Cao, J., Newark, R., Lloyd, N., Schulze, N. and Billow, B. Initial Levitation Testing and Design of Magnetic Bearing System for High Speed Turbo-Aerator Proceedings of ISMB15  
Abstract: This paper concerns the design, construction and initial levitation testing of a full 5-axis magnetic bearing suspen- sion system for an industrial high speed turbo-aerator. The operating speed range of the machine is 16,000 rpm (267 Hz) to 25,000 rpm (417 Hz). The overall turbo aerator configuration is shown and the thrust and radial bearing configurations and design principles are presented. The rotor is a rigid rotor over the operating speed range. The assembled turbo aerator with magnetic bearings is presented with initial test results. The system sensors and power electronics hardware are described in some detail. The casing ping test results are given. The measured PID control results for the rigid rotor for API stability, in terms of AMB system output sensitivity plots show class A operation. Also unbalance rejection control results, with and without the unbalance rejection control, are described.
BibTeX:
@inproceedings{ISMB15_27,
  author = {Simon Mushi and Brad Nichols and Tim Dimond and Paul Allaire and Jianming Cao and Richard Newark and Nigel Lloyd and Nick Schulze and Brad Billow},
  title = {Initial Levitation Testing and Design of Magnetic Bearing System for High Speed Turbo-Aerator},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_27.pdf}
}
2016 Allaire, P., Cao, J., Dimond, T., Mushi, S., Dousti, S., Newark, R., Lloyd, N. and Alshahrani, O. Design of Active Magnetic Radial and Thrust Bearings for High Speed Turbo Aerator Proceedings of ISMB15  
Abstract: The thrust and radial active magnetic bearing (AMB) designs are presented for a 135 kW vertical axis high speed turbo aerator operating at maximum speed of 27,000 rpm. The thrust AMB is a double acting configuration with upperandlowerstatorsandasinglecoil. TheradialAMBisa12poleE-coredesign. Theresultsofmagneticcircuit design, 2-D finite element, and 3-D finite element modeling are presented, indicating that the simple magnetic circuit model is a good initial design tool for both thrust and radial AMBs. The AMBs were actuated with a steady state bias current and a time varying perturbation (control) current. The current gain and open loop stiffness for the AMBs are evaluated, showing the linearity of the bearings. Also, the coil resistance and inductance were evaluated. The bearings were successfully operated in the initial testing. The rotating AMB components must be attached to the rotor securely using shrink fits. The principal and shear stresses induced in the thrust AMB disk and the radial AMB lamination stack were evaluated and found to be in the safe range.
BibTeX:
@inproceedings{ISMB15_28,
  author = {Paul Allaire and Jianming Cao and Tim Dimond and Simon Mushi and Saeid Dousti and Richard Newark and Nigel Lloyd and Omar Alshahrani},
  title = {Design of Active Magnetic Radial and Thrust Bearings for High Speed Turbo Aerator},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_28.pdf}
}
2016 Tsunoda, W., Hijikata, W., Shinshi, T. and Fujiwara, H. Utilizing a radial magnetic bearing to stabilize self-excited vibrations in a rotor-oil film bearing system Proceedings of ISMB15  
Abstract: Oil film bearings have higher load capacity and larger damping than ball bearings. Therefore, the rotors of large turbomachines are usually supported by oil film bearings. However, at high rotational speeds, the swirling flow of the lubricant destabilizes the rotor system and induces self-excited vibrations such as oil whip and oil whirl. Since these vibrations limit the operational speed and reliability, a method for eliminating them and increasing the operational range is necessary. We propose a method for stabilizing these self-excited vibrations by using a radial magnetic bearing (RMB) to cancel the force due to the cross-coupled stiffness described in the Bently-Muszynska model. The purpose of this study is to experimentally examine the relationship between the gain of the controller and the stability.
BibTeX:
@inproceedings{ISMB15_29,
  author = {Wataru Tsunoda and Wataru Hijikata and Tadahiko Shinshi and Hiroyuki Fujiwara},
  title = {Utilizing a radial magnetic bearing to stabilize self-excited vibrations in a rotor-oil film bearing system},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_29.pdf}
}
2016 Duesterhaupt, S., Neumann, H., Rottenbach, T., Vanek, C. and Worlitz, F. High Temperature Active Magnetic Bearings in Industrial Steam Turbines Proceedings of ISMB15  
Abstract: After 8 years of industrial research and development between industry and Zittau/Görlitz University, the prototype of a feed water power turbine (SPAT) with active magnetic bearings was successfully taken in operation at the Jänschwalde power plant in 2015. Due to extended conditions of use (particularly high process and environmental temperatures) the active magnetic bearings in the turbo machines must be cooled elaborately. In conventionally supported turbo machines the lubri- cant in the friction bearings additionally does the cooling. Parts of the heat flux are dissipated from the bearing by the bearing oil. In terms of turbo machines with magnetic bearings lubricant is not used. This leads to significantly higher temperatures in the area of rotor lamination and its sleeves. Particularly demanding is the cooling of the sleeves which is currently very demanding – compressors are necessary. The tube cooling applied reduces the effi- ciency of the magnetic bearing which is high compared with hydrostatic friction bearing. Moreover, the additional peripheral effort has a negative effect for investment and maintenance in cost accounting. This paper shows the stages in developing High Temperature Magnetic Bearings (HTAMB). First approaches of suitable HTAMB concepts are depicted. Within the next 3 years shall on the basis of theoretical and experimental investigations be determined which state of the art materials and construction principles must be used and applied. The focus within that topic is the use of temperature resistant materials for the lamination of active radial magnetic bearings with respect to elimination of high manufacturing effort of sleeve cooling. For this reason the essential tests of magnetic and catcher bearing components shall be realized at the test rig for magnetic and catcher bearings MFLP. Single effects and long-term strain will be analyzed under scaled power plant conditions. The test field is introduced by representing its main parameters.
BibTeX:
@inproceedings{ISMB15_3,
  author = {Stephan Duesterhaupt and Holger Neumann and Torsten Rottenbach and Christian Vanek and Frank Worlitz},
  title = {High Temperature Active Magnetic Bearings in Industrial Steam Turbines},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_3.pdf}
}
2016 Jungmayr, G., Marth, E. and Santner, R. Characteristic quantities of active magnetic bearings Proceedings of ISMB15  
Abstract: In the design of a magnetically levitated system the question arises whether the closed loop can be stabilized by a certain active magnetic bearing (AMB). In this paper we introduce several characteristic quantities which evaluate the static and dynamic capacity of an AMB system. A controller design is not necessary in this novel stability estimation. The calculation of the proposed characteristic quantities can be used to estimate how well an AMB is suited for the stabilization task. Furthermore, the derived dimensionless quantities allow easy comparison of different AMB systems.
BibTeX:
@inproceedings{ISMB15_30,
  author = {Gerald Jungmayr and Edmund Marth and Robert Santner},
  title = {Characteristic quantities of active magnetic bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_30.pdf}
}
2016 Anantachaisilp, P. and Lin, Z. Fractional Order Control of Rotor Suspension by Active Magnetic Bearings Proceedings of ISMB15  
Abstract: This paper demonstrates the design, analysis, and implementation of fractional order PID control (FOPID) for the control of rotor vibration in a centrifugal compressor test rig by active magnetic bearings (AMBs). This is the first time that the FOPID controller is designed for and implemented on an AMB system. In order to achieve the desired design specifications, the controller parameters are tuned by using evolutionary algorithms. Furthermore, a comparison of the performance and efficiency of the FOPID, PID, and an optimal controller is given based on simulation and experimental results.
BibTeX:
@inproceedings{ISMB15_31,
  author = {Parinya Anantachaisilp and Zongli Lin},
  title = {Fractional Order Control of Rotor Suspension by Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_31.pdf}
}
2016 Pesch, A.H. and Sawicki, J.T. Robust Controller Design for AMB Levitation Recovery Proceedings of ISMB15  
Abstract: A control method is proposed for relevitating an active magnetic bearing (AMB) system which has lost levitation due to an acute external fault. The proposed method involves switching to a robust recovery AMB controller once a delevitating event has been detected. The novel recovery controller is uniquely designed for levitation recovery using the robust control strategy μ-synthesis with performance weights which bound the disturbance force of the touchdown (TD) bearing on the rotor. Also, in contrast to typical AMB controller design, the recovery controller is designed to allow potential deflection up to the distance of the TD bearings so as to mitigate amplifier saturation during recovery. The proposed method is demonstrated on an AMB test rig. Details on recovery controller design for the test rig are presented. Rotor drop tests are first used to tune a simple TD bearing model. Then, a numerical simulation is performed to find the frequency response of the TD bearing force on the rotor. The simulated frequency response is used to craft a force bounding performance weight which is then used for robust controller synthesis. The experimental rotor is run at 2000 RPM and a fault is induced by stopping current flow to the AMB coils. After approximately 2 s running on the TD bearings, the power is restored. When no recovery scheme is used, the rotor responds violently, hitting the top of the TD bearing before recovering levitation. With the proposed recovery scheme, the rotor relevitates quickly without unwanted dynamics.
BibTeX:
@inproceedings{ISMB15_32,
  author = {Alexander H. Pesch and Jerzy T. Sawicki},
  title = {Robust Controller Design for AMB Levitation Recovery},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_32.pdf}
}
2016 Sun, F., Xia, P.P. and Oka, K. Robust Adaptive Control of Permanent Magnetic Suspension System Using Variable Flux Path Control Method Proceedings of ISMB15  
Abstract: In order to reduce the power consumption of magnetic suspension system, a magnetic suspension system using variable flux path control method was put forward. And, to stabilize the system, the robust control model is established and status feedback gamma suboptimal H-inf robust controller is designed by H-inf robust control method basing the LMI. Suspension characteristics were analyzed using numerical simulation and experiment, in which the simulation was based on the Matlab/simulink and the experiment was based on the single degree freedom magnetic suspension system. The results show that the suspension system can realize the saving energy suspension, respond displacement input signal. Besides, for the system has a nonlinear characteristic, a static feedback robust controller cannot guarantee the system stability, when the air gap was changed so much. And in order to solve this problem, the adaptive control idea was applied into the system, a robust adaptive control method is proposed. And the robust adaptive control was applied into the suspension system. The simulation and experiment results proved that the controller can obtain a large controllable air gap in a stable suspension state.
BibTeX:
@inproceedings{ISMB15_33,
  author = {Feng Sun and Peng Peng Xia and Koichi Oka},
  title = {Robust Adaptive Control of Permanent Magnetic Suspension System Using Variable Flux Path Control Method},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_33.pdf}
}
2016 Jaatinen, P., Sillanpaa, T., Jastrzebski, R.P., Sikanen, E. and Pyrhonen, O. Automated Parameter Identification Platform for Magnetic Levitation Systems: Case Bearingless Machine Proceedings of ISMB15  
Abstract: This paper presents automated platform that can be used to identify parameters of magnetic levitated systems. Identification platform itself consists of 3-axis force measurement sensors and 2-axis stepper motors driven linear ball screw tracks. This kind of construction enables to measure the force produced by electromagnets in any angle and in any position in the air gap. Measurement system is controllable so the identification process can be automated. As a case study, self and mutual inductances of an interior permanent magnet bearingless machine are identified for the motor control purposes. Force sensors are used to measure the unbalance magnetic pull inflicted by the permanent magnets embedded in the rotor. Automated measuring procedure is used to determine self and mutual inductances of the bearingless motor. System functionality is validated by comparing the measured magnetic pull results to FEM analysis and inductance measurement to different prediction method based on standard motor drive identification process. Based on achieved results presented automated platform can be used to identify parameters of magnetically levitated system.
BibTeX:
@inproceedings{ISMB15_34,
  author = {Pekko Jaatinen and Teemu Sillanpaa and Rafal P. Jastrzebski and Eerik Sikanen and Olli Pyrhonen},
  title = {Automated Parameter Identification Platform for Magnetic Levitation Systems: Case Bearingless Machine},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_34.pdf}
}
2016 Shimura, I., Sugimoto, H. and Chiba, A. Basic Calculation of Axial Force and Torque with Permeance Method in One-Axis Actively Positioned Single-Drive Bearingless Motor Proceedings of ISMB15  
Abstract: This paper presents mathematical calculations of active axial force and torque in a single-drive bearingless motor. The single-drive bearingless motor has only one set of three-phase winding. The active axial force and torque are generated by d- and q-axis currents, respectively. Only the rotor axial z-axis position is actively regulated. The other axes, radial movements x and y, and tilting movements theta-x and theta-y are passively stabilized. In this paper, the mathematical equations of the active axial force and torque based on a permeance method are derived. It is confirmed that calculated force and torque are corresponding with those of three-dimensional finite-element- method analysis.
BibTeX:
@inproceedings{ISMB15_35,
  author = {Itsuki Shimura and Hiroya Sugimoto and Akira Chiba},
  title = {Basic Calculation of Axial Force and Torque with Permeance Method in One-Axis Actively Positioned Single-Drive Bearingless Motor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_35.pdf}
}
2016 Schneider, N., Garvey, S. and Hamiti, T. Control of a single parallel winding bearingless machine Proceedings of ISMB15  
Abstract: This paper proposes a control method for a bearing-less machine (BELM). Unlike most machines that use two separate windings - one for the torque generation and one for the force generation - this study will concentrate on a BELM using a single winding that is able to fulfil the two functions. A model of this BELM was set based on the circuit equation of the electrical machines. Two inductance parameters within the model were introduced to simplify the model of the machine and ease its control. An algebraic formulation of the BELM’s forces is found using an analytical model of the flux changes in the coils as a function of the displacement of the rotor. This is used for the formulation of the energy in the airgap. The obtained results using the analytical model are compared and verified via FEM results. Based on the analytical model of the BELM, a control system that includes a switching functionality for the Voltage Source Inverter (VSI) is implemented to investigate the dynamic control behavior. In addition, a sub-model of the rotating shaft is integrated within the dynamic model to introduce the shaft’s displacement. The obtained results under healthy and different displacement scenarios demonstrate the validity and the performance of the proposed control method for the BELM.
BibTeX:
@inproceedings{ISMB15_36,
  author = {Nicolas Schneider and Seamus Garvey and Tahar Hamiti},
  title = {Control of a single parallel winding bearingless machine},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_36.pdf}
}
2016 Jastrzebski, R.P., Jaatinen, P. and Pyrhonen, O. Modelling and control design simulations of Permanent Magnet Flux-Switching Linear Bearingless Motor Proceedings of ISMB15  
Abstract: For permanent magnet (PM) motor structures in rotating systems, it is typical to retain the magnets in the rotor. This constrains the rotor structure and limits applicability, e.g., for high-speed and high-temperature conditions. Flux-switching PM (FSPM) motors can overcome this limitation. Recently, the FSPM bearingless motors have been developed for special applications. The FSPM concept can be adapted to liner motors. For the linear motors, magnets or windings placed on the mover significantly decrease complexity and cost for longer distances. Still, to separate control of airgap and torque (thrust) two sets of windings or multiphase windings have been required for both rotating FSPM and linear PM machines. The linear FSPM bearingless motor solution, which integrates the magnets, winding structure and all the driving and control electronics on the mover is desired for many applications. However, because of electromagnetic unbalances the machine design is entangled with the control limitations and requirements. We reveal a modelling methodology for accurate derivation of bearingless machine dynamic and static force parameters as a function of airgap, control currents and track position in extended operational range. Model-based control simulations based on the accurate derived plant models determine the achievable machine performance and levitation limitations. The design and modelling methodology is general and can be applied to different PM bearingless motors. In the case study of linear FSPM bearingless motor the airgap control is possible in the equivalent to classical AMBs manner where it is independent from the thrust control.
BibTeX:
@inproceedings{ISMB15_37,
  author = {Rafal Piotr Jastrzebski and Pekko Jaatinen and Olli Pyrhonen},
  title = {Modelling and control design simulations of Permanent Magnet Flux-Switching Linear Bearingless Motor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_37.pdf}
}
2016 Kakinoki, T., Yamaguchi, H., Murakami, T., Mukai, E. and Nishi, H. Development of New Propulsion System for Magnetically Levitated Vehicle Proceedings of ISMB15  
Abstract: This paper describes a new propulsion system for magnetically levitated vehicles with hybrid magnets, which were studied in place of streetcars and transportation systems in semiconductor production. The new propulsion system for magnetically levitated vehicles proposed here is low cost and easy to make. We obtained static experiment results of the linear switched reluctance motor (LSRM) as a new propulsion system, and obtained the basic characteristics.
BibTeX:
@inproceedings{ISMB15_38,
  author = {Toshio Kakinoki and Hitoshi Yamaguchi and Tomoaki Murakami and Eiichi Mukai and Hiroyuki Nishi},
  title = {Development of New Propulsion System for Magnetically Levitated Vehicle},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_38.pdf}
}
2016 David, D.F.B., Santisteban, J.A. and Gomes, A.C.D.N. Laboratory Tests on an Interconnected Four Poles Magnetic Bearing Proceedings of ISMB15  
Abstract: A new structure for active magnetic bearings, based on a successfull idea used in self-bearing motors, has been recently discussed in the literature. A flux interconnection characterizes this idea, and theoretical results predict some advantages of this new model, when compared with the traditional one, with independent flux paths. As an example, a greater equivalent stiffness is expected for this new type of bearing. Two recently built prototypes were used to check whether these expectations really hold true. The main goal of this paper is to present and discuss the prototype details.
BibTeX:
@inproceedings{ISMB15_39,
  author = {Domingos F. B. David and Jose A. Santisteban and Afonso Celso D. N. Gomes},
  title = {Laboratory Tests on an Interconnected Four Poles Magnetic Bearing},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_39.pdf}
}
2016 Kluyskens, V., Beneden, M.V. and Dehez, B. Thermal model for a low-speed flywheel in medium vacuum Proceedings of ISMB15  
Abstract: This paper presents a model aimed to predict the temperature inside a flywheel energy storage system, and more specifically the temperature of the permanent magnet bearings of the system. The windage losses are evaluated by supposing an incompressible Couette flow between the flywheel and the enclosure. The eddy current losses inside the permanent magnet bearing are evaluated by a finite element (FE) electro-mechanical model. Those losses are injected into a FE thermal model. It shows that, in stationary low vacuum conditions, the temperature remains at acceptable levels. The sensitivity of the model to various parameters is also studied. Finally, the case of a loss of vacuum is examined, and it is shown that the system has a high time constant, and that the temperature of the magnets raises slowly enough.
BibTeX:
@inproceedings{ISMB15_4,
  author = {Virginie Kluyskens and Maxence Van Beneden and Bruno Dehez},
  title = {Thermal model for a low-speed flywheel in medium vacuum},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_4.pdf}
}
2016 Yeh, C.T. and Lin, C.H. Thermal Limit Analysis of Radial AMB by Using Finite Difference Method Proceedings of ISMB15  
Abstract: Load capacity of an active magnetic bearings (AMBs) includes the static load capacity, peak transient load capacity and dynamic load capacity. In this paper, a simulation software, SimRaMB, is proposed to estimate the static load capacity which is constrained by the thermal limit of coils. A finite difference method (FDM) algorithm is adopted for the thermal limit analysis of radial AMB. The thermal limit of an eight poles radial magnetic bearing is simulated by SimRaMB and ANSYS, respectively. A thermal test unit of the radial magnetic bearing was built up in which the temperature distributions are measured by 12 thermal couples. The simulation results showed that the difference of temperature at steady-state between SimRaMB and ANSYS is within 0.8° C. The experimental result also showed that the difference of temperature between SimRaMB and experiment is within 0.89°C at lower driving current. However, when the driving current comes to 1.5A and 1.8A, the simulation results of SimRaMB and ANSYS are 8.09°C and 8.58°C higher than experimental data, respectively. The reason could be that the present study doesn’t take into account the influence of temperature to thermal conductivity of material. In order to improve the simulation result, a table of temperature-dependent thermal conductivity will be included in the future.
BibTeX:
@inproceedings{ISMB15_40,
  author = {Chi Ting Yeh and Chung Hsien Lin},
  title = {Thermal Limit Analysis of Radial AMB by Using Finite Difference Method},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_40.pdf}
}
2016 Bonfitto, A., Tonoli, A., Amati, N. and Suarez, L.D. Turbomolecular pumps on active conical magnetic bearings Proceedings of ISMB15  
Abstract: A field in which the magnetic suspensions technology is finding wide application with an increasing rate is the vacuum industry and, in particular, the market of turbomolecular pumps. Nowadays, most used solutions adopted in particular for small to medium pumping capacity are based on hybrid architectures where passive magnetic bearings are combined to ceramic ball bearings. By converse, fully active magnetic suspensions with cylindrical configuration represent the standard for medium to high pumping rate machines. Although simple, the cylindrical configuration is prone to drawbacks related in particular to the straines growing in the disc of the axial actuator that motivate the investigation of alternative architectures. As shown in previous literature, the use of conical configuration, besides compacting driving electronics, seems to be promising considering that the control of the radial and axial degree of freedom is performed simultaneously by the same devices in two actuation planes. This paper describes the main design steps and experimental characterization of a turbomolecular pump supported by conical active magnetic bearings. The control design is based on a SISO decentralized technique with position and control embedded loops. A rotor centering technique based on the characterization of current loops is exposed while the external position loop is tuned measuring relevant transfer functions to refine the controller allowing critical speed crossing. The power actuation of the eight electromagnets is performed with a three-phase configuration drive technique instead of standard H-bridges to minimize the number of power switches. Experimental results along with numerical computations obtained with simulation models are reported in order to prove the validity of modeling approach and the effectiveness of the conical actuation system.
BibTeX:
@inproceedings{ISMB15_41,
  author = {Angelo Bonfitto and Andrea Tonoli and Nicola Amati and Lester Daniel Suarez},
  title = {Turbomolecular pumps on active conical magnetic bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_41.pdf}
}
2016 Sikanen, E., Jastrzebski, R., Jaatinen, P., Sillanpaa, T., Smirnov, A., Sopanen, J. and Pyrhonen, O. Mechanical Design of Reconfigurable Active Magnetic Bearing Test Rig Proceedings of ISMB15  
Abstract: In this study, considerations of a mechanical design of a reconfigurable active magnetic bearing (AMB) test rig and some of its interchangeable modules are reviewed. The manufacturing of modules, assembly, measurements of mechanical accuracies and their influence on electrical and control requirements of the active components are analyzed. Numerical simulations for 10 kW 30000 rpm high-speed rotor of induction motor are performed for studying purposes of rotor dynamics and mechanical stresses of various changeable rotor sleeve parts. Impor- tant part of high-speed AMB system are mechanical backup bearings. Additional sub-modules are designed for changeable backup bearings for further rotor dropdown experiments. Also, reference sensors required by the AMB control system are fitted into own sub-module in order to enable testing of various sensor designs. Experimental measurement are performed in order to study rotor dynamics and mechanical accuracies of modular test rig design. Some operational results during commissioning phase are presented and discussed. The benefits and challenges of using a modular design are discussed. The scope of this paper is in mechanical design, therefore no detailed description of designed AMBs and control system is presented.
BibTeX:
@inproceedings{ISMB15_42,
  author = {Eerik Sikanen and Rafal Jastrzebski and Pekko Jaatinen and Teemu Sillanpaa and Alexander Smirnov and Jussi Sopanen and Olli Pyrhonen},
  title = {Mechanical Design of Reconfigurable Active Magnetic Bearing Test Rig},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_42.pdf}
}
2016 Liang, D., Ozaki, D., Kubo, A., Takahata, R. and Nonami, K. A Study on Zero-bias Simple Adaptive Control AMB System Proceedings of ISMB15  
Abstract: For further evaluation of the zero-bias SAC method, we built a rotor AMB experiment system of which the ratio of the moment of inertia Iz/Ir is almost 1. Zero-bias SAC was introduced to control the attitude/position of rotor and compensate gyro effect. It is difficult to control since the second rigid mode (2R) forward natural vibration frequency grows parallel with the rotation frequency which means that 2R natural vibration will keep influencing the rotor during rotation. With conventional PID method, orbits of rotor became unstable when rotation frequency increased to about 100Hz. In comparison, with SAC method we rotated up to 225Hz perform without any gyro effect and the orbits of rotor were considerably stable.
BibTeX:
@inproceedings{ISMB15_43,
  author = {Dong Liang and Daisuku Ozaki and Astushi Kubo and Ryouichi Takahata and Kenzo Nonami},
  title = {A Study on Zero-bias Simple Adaptive Control AMB System},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_43.pdf}
}
2016 Seifert, R. and Hofmann, W. Analytical Asymmetric Air Gap Model for Active Magnetic Thrust Bearings of Mixed Materials Including Eddy Currents Proceedings of ISMB15  
Abstract: The electrodynamics of magnetic thrust bearings are characterized by an above-average dependency on the used materials. Axially directed fields render laminated stators and rotors ineffective. High induced voltages inside the magnetic core evoke eddy currents and opposing fields, which are compensated by an additional magnetizing cur- rent causing a significant delay between the measurable coil current and the force-related magnetic flux. Although this effect, hampering control dynamics, can be reduced by the use of Soft Magnetic Composites for non-rotating parts, the thrust disk will be made of steel due to its superior tensile strength and saturation flux density. The analytical modeling of mixed-material magnetic thrust bearings reveals new challenges arising from asymmetries and low permeable magnetic core sections, which are both addressed in this paper.
BibTeX:
@inproceedings{ISMB15_44,
  author = {Robert Seifert and Wilfried Hofmann},
  title = {Analytical Asymmetric Air Gap Model for Active Magnetic Thrust Bearings of Mixed Materials Including Eddy Currents},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_44.pdf}
}
2016 Cole, M.O.T. and Chamroon, C. H-infinity controller design for active magnetic bearing systems considering nonlinear vibrational rotordynamics Proceedings of ISMB15  
Abstract: This paper deals with optimal controller design for active magnetic bearing (AMB) systems for which nonlinear rotordynamic behavior is evident, and so vibration predicted by operating point linearization differs substantially to that which actually occurs. Nonlinear H-infinity control theory is applied with a rotordynamic model involving nonlinear stiffness and/or damping terms. The associated Hamilton-Jacobi-Isaacs (HJI) equation is formulated and solved to obtain a state feedback control law achieving specified vibration attenuation performance in terms of the peak L 2 gain of the nonlinear system. The method is applied in case study to a flexible rotor/AMB system that exhibits nonlinear stiffness properties owing to rotor interaction with a clearance bearing. Simulations are performed to quantify RMS vibration due to harmonic disturbances and the results compared with the norm-bound values embedded in the HJI equations. A feedback controller design method is then presented that is similar in approach to the standard loop-shaping/mixed-sensitivity methods used for linear systems, and involves augmenting the system model with weighting transfer functions. Experiments are undertaken to compare controller performance for design based on nonlinear and linearized models. The results highlight the shortcomings of applying linear optimal control methods with rotor systems exhibiting nonlinear stiffness properties as large amplitude vibration and loss of rotordynamic stability can occur. Application of the described nonlinear H-infinity control method is shown to overcome these problems, albeit at the expense of vibration attenuation performance for operation in linear regimes.
BibTeX:
@inproceedings{ISMB15_45,
  author = {Matthew O. T. Cole and Chakkapong Chamroon},
  title = {H-infinity controller design for active magnetic bearing systems considering nonlinear vibrational rotordynamics},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_45.pdf}
}
2016 Jimenez, S. and Keogh, P. Control of Magnetic Bearings with Rotor-Mounted Accelerometers Proceedings of ISMB15  
Abstract: Mounting MEMS accelerometers inside hollow shaft rotors has been proposed as a novel sensor design for vibra- tion monitoring and control in rotating machinery. The application of this technology to Active Magnetic Bearings (AMB) could allow sensor/actuator collocation. This paper explores the possibility of using rotor-mounted ac- celerometers as standalone sensors for AMB control. The integration of the acceleration signals, after conversion from the rotating to the inertial reference frame, is considered as a means to extract rotor displacement informa- tion. The sensitivity of this method to uncertainty in the measurement of the gravitational component and in the estimation of the initial angular position is studied. The latter produces a steady state error in the rotor position estimation which cannot be measured by the accelerometers. Therefore, a current injection technique has been developed to eliminate this error. The method produces a low-amplitude, high-frequency response in the rotor, which has negligible effect on the rotordynamics, but is easily detected by accelerometers and allows the steady state error to be estimated and reduced. The simulation of a disc being levitated in an AMB system using only internal accelerometers has been undertaken and results are reported.
BibTeX:
@inproceedings{ISMB15_46,
  author = {Samuel Jimenez and Patrick Keogh},
  title = {Control of Magnetic Bearings with Rotor-Mounted Accelerometers},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_46.pdf}
}
2016 Zhang, K., Yin, J. and Dai, X. A Smooth Switch between Different Unbalance Control Parameters in Rotor Systems with Active Magnetic Bearings Proceedings of ISMB15  
Abstract: Unbalance control is necessary for rotor systems with active magnetic bearings (AMBs), especially for vibration sensitive applications such as flywheels and turbo molecular pumps. When a special unbalance control method is used in an AMB rotor system, its key feedback parameters such as gain matrix parameters are usually closely related to the AMB model, which changes with the rotation speed of the rotor. For simplicity and convenience, the feedback gain parameters can keep constant in a special speed range and change to different new constant values when the rotation speed enters a close range. It is also possible to use a special method in the previous speed range and use another method in the close range. The switch between unbalance control algorithms needs a suitable method to ensure the stability and smoothness of a switch process. Different switch methods including a direct switch method, a linear switch method and an overlying switch method are introduced and verified in a flywheel system with AMBs. Their effects in switching between two General Notch Filter matrices were verified by simulation and experiments. The simple overlying switch method proved its performance and achieved a very stable and smooth algorithm switch.
BibTeX:
@inproceedings{ISMB15_47,
  author = {Kai Zhang and Jiuchao Yin and Xingjian Dai},
  title = {A Smooth Switch between Different Unbalance Control Parameters in Rotor Systems with Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_47.pdf}
}
2016 Asama, J., Sasaki, K., Oiwa, T. and Chiba, A. Simplified Configuration of a Two-DOF Actively Controlled Bearingless Motor Using Two H-Bridges Proceedings of ISMB15  
Abstract: This paper introduces a new structure and topology of a two-degrees-of-freedom (DOF) actively controlled bearingless motor using only two H-bridges (four half-bridges). The proposed two-DOF controlled bearingless motor has two-phase integrated motor windings. The neutral point of each phase winding is connected to the middle point of the inverter’s dc power voltage. This bearingless motor, thus, offers common dq-axis current vector control for permanent magnet motor drive as well as radial two-DOF active positioning control of the rotor. In this paper, the suspension force and toque of the 2-pole/8-slot model are theoretically derived from the stored magnetic energy. The magnetic energy is calculated from the inductance matrix where each inductance component is derived with the air-gap magnetic flux distribution. The theoretically calculated results show how the suspension force and torque are regulated with the control currents. To verify the theoretical calculation, two-dimensional FEM analysis is performed. The FEM calculation demonstrates that the proposed bearingless motor topology with 2-pole/8-slot structure using only two H-bridges generates constant suspension force and torque.
BibTeX:
@inproceedings{ISMB15_48,
  author = {Junichi Asama and Kenta Sasaki and Takaaki Oiwa and Akira Chiba},
  title = {Simplified Configuration of a Two-DOF Actively Controlled Bearingless Motor Using Two H-Bridges},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_48.pdf}
}
2016 Hida, S. and Morishita, M. Modeling of a Single Point Suspended Electromagnetic Suspension Carrier System Study on Rolling Motion Proceedings of ISMB15  
Abstract: Authors made a single point suspended electromagnetic suspension (EMS) system. This EMS system was applied to a transport system. This transport system has a carrier and a guide. The carrier is provided with a magnet unit and a carrier body. The magnet unit which comprises two coils, two iron core and a permanent magnet, suspends the carrier with no contact. The guide comprises an iron plate and propelling coils. When the carrier passes through the curved section of the guide, pendulum motion occurs in the rolling direction. This is rolling motion. The rolling motion continues longer than the pitching motion caused by acceleration and deceleration. When the carrier is swaying, eddy current mainly induces in the iron plate because a magnetic field in an air gap between the iron core and the iron plate changes. The eddy current makes a difference of the convergence times between the rolling and the pitching motions. Our former research modeled the pitching motion of the carrier by considering the eddy current loss and a movement of the action point of the attractive force acting on the magnet unit. In this paper, authors make the model of the rolling motion by the same method. The validity of the modeling method is verified with simulational and experimental results.
BibTeX:
@inproceedings{ISMB15_49,
  author = {Shogo Hida and Mimpei Morishita},
  title = {Modeling of a Single Point Suspended Electromagnetic Suspension Carrier System Study on Rolling Motion},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_49.pdf}
}
2016 Rudolph, J. and Werner, R. Theoretical Basics and Closed Loop Control Design of Stray-Flux-Based Measurement Systems for Magnetic Bearings Proceedings of ISMB15  
Abstract: In this paper the theoretical basics of a measurement system are given in detail which uses magnetic stray fluxes for sensing the rotor position in magnetic bearings. Reluctance models for the most spread types of magnetic bearings are evolved to create the mathematic equations in the form of matrices. Based on this a description of the dependence of the magnetic stray flux that occurs and the air gap length respectively the rotor position by analytical and numerical calculations can be done. It will be shown that this behavior of stray flux depends on where it is measured. Additional the influence of the coil current and its transient behavior on this measurement system will be discussed. Furthermore the application in an eight pole heteropolar magnetic bearing will be presented. Therefore a signal flow diagram is given that clarifies in which way the measured HALL-signals should be processed to generate a position signal as input for an PID-controller that provides a stable levitated rotor in the bearing center. Last but not least the courses of the stray flux based position signals are presented compared with the signals of an auxiliary capacitive measurement system and approaches are proposed for a further improvement of this alternative measurement system using typically neglected magnetic stray fluxes.
BibTeX:
@inproceedings{ISMB15_5,
  author = {Johannes Rudolph and Ralf Werner},
  title = {Theoretical Basics and Closed Loop Control Design of Stray-Flux-Based Measurement Systems for Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_5.pdf}
}
2016 Manninen, A., Mukherjee, V. and Pippuri, J. A Self-bearing 8/6 Switched Reluctance Motor Proceedings of ISMB15  
Abstract: This paper describes a self-bearing 8/6 switched reluctance motor (SRM). The main challenge with such a motor is how to control both torque and radial forces. This task is particularly challenging because the double saliency of the machine type causes the characteristics of the motor to be highly nonlinear. In this paper, we first present a switching logic for the 8 stator coils. The current in the 8 phases is defined by using three current components and the rotor angle. After that, we propose a model that could be used in the closed loop control to solve the required stator currents from needed radial forces and torque. The force and torque models are based on first and second order polynomials, which are fitted to data that have been obtained by two-dimensional electromagnetic finite element analysis. In this paper we compare the performance of the analytical model with the finite element analysis data, and use the analytical model for direct open loop control. The results show that the proposed analytical model can be used to calculate the required stator currents that are needed to operate the self-bearing SRM. The models can be combined with closed loop control methods in order to properly control the machine.
BibTeX:
@inproceedings{ISMB15_50,
  author = {Aino Manninen and Victor Mukherjee and Jenni Pippuri},
  title = {A Self-bearing 8/6 Switched Reluctance Motor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_50.pdf}
}
2016 Allaire, P., Nichols, B., Dimond, T., Cao, J. and Mushi, S. Low Cost Active Magnetic Bearings - Concepts and Examples Proceedings of ISMB15  
Abstract: The objective of this paper is to present innovative new thrust and radial magnetic bearing designs using permanent magnet bias not previously published. They are expected to be significantly lower in cost than conventional all electromagnetic bearings. The new designs use permanent magnet bias in a way not introduced before. The resulting magnetic bearings are able to use only half of the number of power amplifiers than conventional magnetic bearings, as well as consuming significantly less operating power in the bearing coils. However, the bearings are generally not larger than conventional all electromagnetic bearings. Finally, these new permanent magnet bias bearing designs are generally not longer axially than all electromagnetic bearing designs, unlike other types of permanent magnet bias designs such as homopolar magnetic bearings. This is important from the rotor dynamics point of view. This innovation has the potential to reduce the overall magnetic bearing system hardware volume production cost by 20% to 30% as well as reduce coil current operating costs in the range of 35% to 40%.
BibTeX:
@inproceedings{ISMB15_51,
  author = {Paul Allaire and Brad Nichols and Tim Dimond and Jianming Cao and Simon Mushi},
  title = {Low Cost Active Magnetic Bearings - Concepts and Examples},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_51.pdf}
}
2016 Smirnov, A., Uzhegov, N., Hartikainen, T. and Pyrhonen, J. Design Aspects of AMBs for High-Speed Permanent Magnet Synchronous Machine Proceedings of ISMB15  
Abstract: Distributed power generation is nowadays one of the global trends. Compared with the centralized power gen- eration there is no need to transmit and regulate electricity network in the case of distributed generation. These advantages can be critical for many electricity consumers. Distributed power generation using microturbines is an alternative to the commonly used combustion engines. These installations increase total system efficiency and enable operation at the low partial loads. In this paper the design aspects of a high-speed permanent magnet syn- chronous machine (PMSM) equipped with active magnetic bearings (AMBs) are considered. The structure of the permanent magnet generator is explained and its parameters are presented and discussed. This paper concentrates on the additional magnetic pull created by the PMSM at standstill. This situation creates extra forces and set extra requirements to AMBs. The method to avoid unnecessary magnetic bearing overdimensioning using electrical machine control system is described. An influence of the unbalanced magnetic pull on the active magnetic bearing control is presented. The uneven distribution of the force leads to additional complexity for the controller synthesis. The rotating reference frame for the control problem formulation is discussed.
BibTeX:
@inproceedings{ISMB15_52,
  author = {Alexander Smirnov and Nikita Uzhegov and Toni Hartikainen and Juha Pyrhonen},
  title = {Design Aspects of AMBs for High-Speed Permanent Magnet Synchronous Machine},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_52.pdf}
}
2016 Huang, Z., Le, Y. and Han, B. Design of AMB and Rotordynamics for a 30kW, 60 000 rpm Permanent-magnet Machine Proceedings of ISMB15  
Abstract: Due to the long lifetime requirement and high rotating speed, an active magnetic bearing is designed for a 30 kW, 60 000 rpm permanent magnet machine application. The electromagnetic distribution characteristics of the active magnetic bearing are analyzed under the static levitation and the maximum bearing capacity using 2D finite element method. According to the large error problems of the calculation of the critical speed of the rotor assembly, this paper presents a model updating method to establish the finite element model of the rotor assembly. The calculated results of the first two bending critical speeds are verified by using the modal testing. The errors of the first two bending critical speed are 3.2 % and 1.8, respectively.
BibTeX:
@inproceedings{ISMB15_53,
  author = {Ziyuan Huang and Yun Le and Bangcheng Han},
  title = {Design of AMB and Rotordynamics for a 30kW, 60 000 rpm Permanent-magnet Machine},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_53.pdf}
}
2016 Hutterer, M., Hofer, M. and Schroedl, M. New Results on the Robustness of Selfsensing Magnetic Bearings Proceedings of ISMB15  
Abstract: This paper shows the design and new results of a self-sensing homopolar active magnetic bearing (AMB). The considered magnetic bearing provides the bias flux using permanent magnets. Only the control flux for the stabi- lization of the system is provided by electro-magnets. This so called hybrid magnetic bearing (HMB) minimizes the energy losses and shows a high linearity. Therefore, this structure is a good choice for industrial applications which uses position sensors for closing the control loop. However, the self-sensing control of such bearing types require a position dependent inductance. Many homopolar structures share the same flux at two opposite poles and the coils of these poles are connected in serial. Hence, the inductance is almost independent of the rotor position. The proposed bearing type shows a way where also a hybrid homopolar magnetic bearing can be controlled with- out external position sensors. The self-sensing method is based on inductance measurement by applying voltage pulses to the system. The current slope is measured directly using an induction ring. A differential evaluation of the current slopes increases the position dependent part of the signal and decreases the errors due to eddy currents and the leakage flux. The last part of the paper shows the measured sensitivity function of the system at standstill and rotational speed.
BibTeX:
@inproceedings{ISMB15_54,
  author = {Markus Hutterer and Matthias Hofer and Manfred Schroedl},
  title = {New Results on the Robustness of Selfsensing Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_54.pdf}
}
2016 Chen, S.-L. and Hsiao, Y.-H. Smooth Voltage Controller and Observer for a Three-pole Active Magnetic Bearing System Proceedings of ISMB15  
Abstract: In this study, a simple and smooth voltage controller for a 3-pole active magnetic bearing (AMB) system is proposed. Based on the voltage-controlled AMB system, an observer is designed for the rotor displacement estimation. The observer will be based on the input voltages and coil currents that drive the magnetic poles. Such an observer can be utilized in the sensorless control of the AMB system. Due to the strong nonlinearity in the dynamics of 3-pole AMB system, the theory of nonlinear high-gain observer is adopted to design the observer. The proposed smooth voltage controller and nonlinear observer are verified numerically and experimentally.
BibTeX:
@inproceedings{ISMB15_55,
  author = {Shyh-Leh Chen and Yung-Ho Hsiao},
  title = {Smooth Voltage Controller and Observer for a Three-pole Active Magnetic Bearing System},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_55.pdf}
}
2016 Hofer, M., Hutterer, M. and Schroedl, M. PCB Integrated Differential Current Slope Measurement for Position-Sensorless Controlled Radial Active Magnetic Bearings Proceedings of ISMB15  
Abstract: This paper discusses a current slope measurement principle for self-sensing active magnetic bearings (AMBs). So called sensorless or self-sensing principles avoid external position sensors in the AMB and use the inductance dependency on the rotor position of the AMB itself to determine the rotor position for feedback control. By the help of a transformer core a combined evaluation of both opposite AMB coil inductances is possible. This differential approach determines the sensorless rotor position with high accuracy which allows a robust self-sensing AMB operation. The disadvantage of applying a wound transformer core can be overcome by a novel planar coil arrangement integrated in the printed circuit board of the AMB inverter. Different yoke materials for an optimal flux closure of the novel current slope sensing unit are investigated regarding to dynamic response and a high position sensitivity. Finally, experimental results of high permeable materials with well high frequency properties as ferrites or SMC confirm the sensing principle and allow a position-sensorless control of a three phase AMB.
BibTeX:
@inproceedings{ISMB15_56,
  author = {Matthias Hofer and Markus Hutterer and Manfred Schroedl},
  title = {PCB Integrated Differential Current Slope Measurement for Position-Sensorless Controlled Radial Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_56.pdf}
}
2016 Sugimoto, H., Shimura, I. and Chiba, A. Design Consideration for Performance Improvement in One-Axis Actively Positioned Single-Drive Bearingless Motor Proceedings of ISMB15  
Abstract: This paper presents rotor structures to enhance the active axial force in a single-drive bearingless motor. The single-drive bearingless motor can generate both torque and active axial force by q- and d-axis currents, respectively, with only one three-phase inverter. The axial z-axis position is actively regulated, but the other axes, radial and tilting movements, are passively stabilized. In this paper, the rotor structure is improved to enhance the active axial force. The active axial force and the other important performance parameters are calculated in three-dimensional finite-element-method analysis. In addition, the performance is comprehensively evaluated.
BibTeX:
@inproceedings{ISMB15_57,
  author = {Hiroya Sugimoto and Itsuki Shimura and Akira Chiba},
  title = {Design Consideration for Performance Improvement in One-Axis Actively Positioned Single-Drive Bearingless Motor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_57.pdf}
}
2016 Radman, K. and Gruber, W. High Torque Bearingless Flux-Switching Slice Drive Proceedings of ISMB15  
Abstract: This paper presents the development of a bearingless flux-switching slice drive. Belonging to the bearingless drive family, all active and passive suspension forces are generated in the same radial plane and with the same electromechanical components which generate the motor torque. This research had the goal of improving the torque capabilities of the drive while still maintaining adequate passive slice-rotor stabilization. Optimization goals included the increment of the air gap and the motor torque increase, two opposing demands. A working prototype was built from the optimized simulation model. The prototype’s torque and suspension force performances were measured and compared to the FEM simulation results. Additionally, a new control model is proposed for the bearing force generation.
BibTeX:
@inproceedings{ISMB15_58,
  author = {Karlo Radman and Wolfgang Gruber},
  title = {High Torque Bearingless Flux-Switching Slice Drive},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_58.pdf}
}
2016 Noh, M. and Gruber, W. Homopolar Hyteresis Bearingless Motors Proceedings of ISMB15  
Abstract: We present a new concept of bearingless slice motors that levitates and rotates a ring-shaped rotor made of a semi-hard magnetic material such as D2 steel. The rotor is biased with a homopolar permanent-magnetic flux, on which 2-pole flux can be superimposed to generate suspension forces. The torque is generated by a hysteretic coupling between the rotor and a rotating 6-pole stator field. We discuss the design of the prototype system and its performance estimates from FEA simulations.
BibTeX:
@inproceedings{ISMB15_59,
  author = {Minkyun Noh and Wolfgang Gruber},
  title = {Homopolar Hyteresis Bearingless Motors},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_59.pdf}
}
2016 Nam, S., Noh, M.D., Park, Y.-W. and Lee, N.S. Estimation of Magnetic Center Location in Radial Active Magnetic Bearings Through a Pull Test Proceedings of ISMB15  
Abstract: The misalignment between the mechanical center and the magnetic center in a radial active magnetic bearing can cause serious problems and must be measured before commissioning the machine for field deployment. Once a suspension controller is operating, the misalignment can be estimated from the coil current imbalance. In this paper, we present a method of estimating the misalignment without the need for suspension. Through a simple test where the rotor is pulled to several different directions, the magnetic center can be estimated. For this purpose, a force model that relates the coil current and the force that the rotor experiences is derived. Utilizing this force model, a minimization proble is set up, where the discrepancies between the contact angle measurements and the force angles computed from the force model are minimized. The results of this minimization produce the estimation of the magnetic center. The validity of the method is checked through simulations and experiments.
BibTeX:
@inproceedings{ISMB15_6,
  author = {Sunggyu Nam and Myounggyu D. Noh and Young-Woo Park and Nam Soo Lee},
  title = {Estimation of Magnetic Center Location in Radial Active Magnetic Bearings Through a Pull Test},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_6.pdf}
}
2016 Hasan, S.M., Mizuno, T., Takasaki, M. and Ishino, Y. Design of an Enlarged Wind Tunnel System for Spinning Body Using Magnetic Suspension Proceedings of ISMB15  
Abstract: A new wind tunnel system for a spinning body is designed for the measurement of the hydrodynamic forces acting on the body. In this system a ferromagnetic sphere (floator) is considered to be suspended and rotated by electromagnets. The diameter and weight of this floator are 19.5mm and 28.4 g, respectively. For observing the accurate hydrodynamic phenomena around the floator by reducing the interferences with the walls, the cross section of the test chamber of the wind tunnel in the vertical plane is set to be 100×100 mm. Wind flow is considered to be in the negative x-axis direction. For compensating the effect of the wind flow, force in the opposite direction is necessary. To make a significant difference of the resultant horizontal force in this direction, the poles are arranged asymmetrically, which is a special characteristic of this design. Stable suspension and three-dimensional positioning of the body is achieved in the developed system. Spinning of the body is realized by superimposing two-phase AC signals on the control signal.
BibTeX:
@inproceedings{ISMB15_60,
  author = {Shahajada Mahmudul Hasan and Takeshi Mizuno and Masaya Takasaki and Yuji Ishino},
  title = {Design of an Enlarged Wind Tunnel System for Spinning Body Using Magnetic Suspension},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_60.pdf}
}
2016 Smirnov, A., Uzhegov, N., Sillanpaa, T., Pyrhonen, J. and Pyrhonen, O. Design and evaluation of high-speed solid rotor induction machine supported by AMBs with a multidisciplinary tool Proceedings of ISMB15  
Abstract: For high-speed electrical machines compact design is one of their advantages and further system integration is required to increase a system efficiency. A growing level of the technical system integration may cause additional design problems and increase design time. In this work the design procedure and design optimization of high-speed electrical machines supported by Active Magnetic Bearings (AMBs) are described. First, the design of the high- speed induction motor, bearings, and rotor are analyzed. Then, the boundary conditions and optimization variables are selected based on the key system performance indicators. The optimization variables include, for example, rotor outer diameter, number of rotor bars, slit depth ratio, and some other. Finally, an optimization procedure is presented, including objectives for the optimization procedure, fitness function, and selected algorithm. The pre- sented procedure is tested with an example of high-speed induction machine with solid rotor equipped with AMBs. Based on the optimization results the prototype is constructed. An implementation of the optimization procedure prevented extra iterations during the final design stage and reduced total design time. With slight modifications this procedure is applicable for other types of high-speed electrical machines supported by AMBs.
BibTeX:
@inproceedings{ISMB15_61,
  author = {Alexander Smirnov and Nikita Uzhegov and Teemu Sillanpaa and Juha Pyrhonen and Olli Pyrhonen},
  title = {Design and evaluation of high-speed solid rotor induction machine supported by AMBs with a multidisciplinary tool},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_61.pdf}
}
2016 Wang, J. and Su, J. The Design of A Centrifugal Blower Rotor with Magnetic Bearings Based on Rotor Dynamics Proceedings of ISMB15  
Abstract: A maglev centrifugal blower rotor with magnetic bearings is designed and developed by rotor dynamics. The shaft diameter is initially set according to the magnetic bearings and engineering experience, the finite element model calculation shows the first bending critical speed of the initially designed rotor without silicon steel sheets is closed to the rated speed. To avoid the resonance, the shaft diameter of magnetic bearings section increases and the length of left and right enameled wire section are reduced, thus the first bending critical speed increases, which and the second rigid critical speed have more than 15% margin to the rated speed within support stiffness of 10 5 N/m 10 7 N/m, the first bending critical speed of the revised rotor with silicon steel sheets increases a little compared to that without silicon steel sheets. At the condition of dynamic balance grade of G2.5 and the damping ratio of 0.707, the vibration amplitudes of the revised rotor are far less than the protective gap, the gyroscopic effect influences more and more with the increase of angular speed, so that the vibration amplitudes with different support stiffness tend to be the same, then the lower support stiffness such as 5×10 5 N/m can be chosen to facilitate the control system design.
BibTeX:
@inproceedings{ISMB15_62,
  author = {Junting Wang and Jiageng Su},
  title = {The Design of A Centrifugal Blower Rotor with Magnetic Bearings Based on Rotor Dynamics},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_62.pdf}
}
2016 Franz, D. Algorithms for self-sensing magnetic bearings using current signals and least square identification Proceedings of ISMB15  
Abstract: This paper discusses self-sensing algorithms based on least square identification for active magnetic bearings under strong eddy current influence. The considered algorithms use current data which are acquired at high frequency to estimate the air gap size by means of the actuator inductance. Eddy currents lead to a nonlinear current increase. This can result in poor position estimation accuracy when linear approximations are used. To face this problem, two approaches are considered. In the first an exponential trial function is introduced to compensate the eddy currents. Potential problems arise, because the exponent cannot be fitted with least square identification and therefore has to be taken as constant. The other utilizes the current data of two counteracting electromagnets, which are driven asymmetrically. To compensate eddy currents as well as movement induction the signals are added up, unlike other publications where they are subtracted. The estimation algorithms are investigated with measured current data. The first reduces the error to 40 % of a reference algorithm. The second shows further improvement to 20 % of the reference. However, the error absolute values are still too high for industrial applications. The paper closes with a proposal for further improvement.
BibTeX:
@inproceedings{ISMB15_63,
  author = {Daniel Franz},
  title = {Algorithms for self-sensing magnetic bearings using current signals and least square identification},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_63.pdf}
}
2016 Hofer, M., Hutterer, M. and Schroedl, M. Application of Soft Magnetic Composites (SMCs) in Position-Sensorless Controlled Radial Active Magnetic Bearings Proceedings of ISMB15  
Abstract: In this paper a soft magnetic composite (SMC) material is applied to permanent magnet (PM) biased radial active magnetic bearings (AMB) and investigated regarding position-sensorless control. A bias flux generation by per- manent magnets with a homopolar bearing structure requires the closure of the bias flux in axial direction. Thus, accordant magnetic properties in all three dimensions are required from the applied materials. The isotropic behav- ior of SMCs may offer advantages compared to a classical realization with laminated electrical steel. Further, for a self-sensing AMB operation the high frequency (HF) aspects of the iron path have relevance for the sensorless position evaluation regarding dynamics and accuracy. Because of these two reasons applying SMC material to this AMB topology is an interesting alternative to common setups with laminated electrical steel. Two AMB proto- types at same geometry and different materials are investigated by experiments. In this work key parameters of bias flux density, force-current characteristic, operational losses and self-sensing properties are compared. Finally, a conclusion shows, that the apparent material advantages of SMC are not utilized in this AMB application.
BibTeX:
@inproceedings{ISMB15_64,
  author = {Matthias Hofer and Markus Hutterer and Manfred Schroedl},
  title = {Application of Soft Magnetic Composites (SMCs) in Position-Sensorless Controlled Radial Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_64.pdf}
}
2016 Yu, J. and Zhu, C. An analytical frequency-domain model of self-sensing magnetic bearing: modulation approach Proceedings of ISMB15  
Abstract: This article introduces an analytical model of the self-sensing process in the self-sensing active magnetic bearings. In this model, the switching harmonics of the PWM amplifier and the demodulator’s output are expressed analytically in the frequency domain, thus the nonlinear self-sensing process can be regarded as a “virtual displacement sensor” with precise input-output relationships. Then, the sensitivity of the virtual displacement sensor is investigated, which indicates that the virtual sensor’s sensitivity not only has varying values with different system parameters but also deteriorates significantly in the high frequency region. Fortunately, an acceptable sensitivity of the virtual displacement sensor can still be maintained if the system is properly designed, which is also verified by experimental results on a four degree-of-freedom self-sensing radial AMBs rigid rotor platform.
BibTeX:
@inproceedings{ISMB15_65,
  author = {Jie Yu and Changsheng Zhu},
  title = {An analytical frequency-domain model of self-sensing magnetic bearing: modulation approach},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_65.pdf}
}
2016 Saarakkala, S., Sokolov, M., Mukherjee, V., Pippuri, J., Tammi, K. and Belahcen, A. Flux-Linkage Model Including Cross Saturation for a Bearingless Synchronous Reluctance Motor Proceedings of ISMB15  
Abstract: This paper deals with magnetic modeling of a bearingless synchronous reluctance motor. The motor under consid- eration includes two separate sets of three-phase windings, one for torque production and the other one for radial- force production. This paper demonstrates by means of finite-element analysis, that it is unrealistic to assume the two three-phase windings to be decoupled from one another. Instead, it is shown that especially the torque- producing winding currents affect to the operation of the radial-force producing winding. A simple nine-parameter explicit-function based magnetic model is proposed to model the cross-saturation between the two winding sets. The effectiveness of the proposed magnetic model is demonstrated by applying it together with model-based torque and radial-force controllers.
BibTeX:
@inproceedings{ISMB15_66,
  author = {Seppo Saarakkala and Maksim Sokolov and Victor Mukherjee and Jenni Pippuri and Kari Tammi and Anouar Belahcen},
  title = {Flux-Linkage Model Including Cross Saturation for a Bearingless Synchronous Reluctance Motor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_66.pdf}
}
2016 Kurita, N. Basic Design of the Maglev Pump for Total Artificial Heart by using Double Stator Type Axial Self-bearing Motor Proceedings of ISMB15  
Abstract: Due to the high rate of heart disease and a shortage of donor hearts, there has been a longstanding interest to develop mechanical replacements for the heart. A magnetically levitated motor is one of the key technology to develop a total artificial heart and bi-ventricular assist device. A double side stator type axial self-bearing motor with a tilt control function, in addition to rotation and translation motion control, was proposed. A slice rotor can be used due to tilt control function. The surface area of a stator and a rotor becomes large. The high torque self-bearing motor is realizable. The operating principle of the proposed self-bearing motor was explained and fundamental characteristics of the motor were tested. In addition, a basic design of the maglev pump by using the proposed axial SBM is presented. The operating principle was clarified that rotation control, translation control and tilt control show no interference. These four axes are, therefore, able to be controlled independently. According to the experimental result, the fabricated self-bearing motor showed good levitation and rotation performance. Moreover, the basic design of the maglev pump was presented.
BibTeX:
@inproceedings{ISMB15_67,
  author = {Nobuyuki Kurita},
  title = {Basic Design of the Maglev Pump for Total Artificial Heart by using Double Stator Type Axial Self-bearing Motor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_67.pdf}
}
2016 Lapotre, B., Nahid-Mobarakeh, B., Takorabet, N., Meilbody-Tabar, F. and Lateb, R. Active suppression of structural force harmonics in PM bearingless motors Proceedings of ISMB15  
Abstract: In permanent magnet (PM) bearingless motors some design characteristics can create ripples on force during the rotation depending on the levitation current and the rotational speed. This paper proposes a method to eliminate these ripples by the injection of additional current harmonics. This current is injected by a special structure of control taking into account the interaction highlighted by the theatrical analysis of the force ripples. This control method is validated by experimental results.
BibTeX:
@inproceedings{ISMB15_68,
  author = {Blaise Lapotre and Babak Nahid-Mobarakeh and Noureddine Takorabet and Farid Meilbody-Tabar and Ramdane Lateb},
  title = {Active suppression of structural force harmonics in PM bearingless motors},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_68.pdf}
}
2016 Komori, M., Watanabe, K., Katou, H., Asami, K.-I. and Sakai, N. Basic Study on Active Magnetic Bearing working in Liquid Nitrogen Proceedings of ISMB15  
Abstract: This paper discusses an active magnetic bearing (AMB) able to work in liquid nitrogen, which is composed of a stator with four electromagnets (EMs), a rotor, displacement sensors, a permanent magnet (PM) motor, etc. In this paper, two types of AMBs are discussed. The one AMB is made to study basic characteristics of the AMB in liquid nitrogen. The other one is made to study basic characteristics of the pump able to work in liquid nitrogen. The rotor is levitated in the center of the stator with a pivot bearing at the rotor bottom. The pump performances using the AMB are studied by measuring the displacement of the spinning rotor at extremely low temperature -200C.
BibTeX:
@inproceedings{ISMB15_69,
  author = {Mochimitsu Komori and Kenshi Watanabe and Hirohisa Katou and Ken-Ichi Asami and Nobuo Sakai},
  title = {Basic Study on Active Magnetic Bearing working in Liquid Nitrogen},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_69.pdf}
}
2016 Jastrzebski, R.P., Sillanpaa, T., Jaatinen, P., Smirnov, A., Vuojolainen, J., Lindh, T. and Laiho, A. Automated Design of AMB Rotor Systems with Standard Drive, Control Software and Hardware Technologies Proceedings of ISMB15  
Abstract: Industrial applications of active magnetic bearings (AMBs) technology have been continuing to grow for over 4 decades. However, the volume and cost reduction for consumer products are still lower than industrial potential. Particularly, bearing design to match the application, control design, commissioning, control tuning, electronics design and scaling of VA rating to match the bearings make the significant contribution to overall cost of new AMBs. This paper describes how to design and implement an industrial 5 degrees of freedom AMB suspension and model-based control for rotating systems quickly and efficiently. The presented solution leverages the existing commercialized drives and automation components for making the AMB products. With the automated analytical design of AMB actuators and control in respect to design constrains the design & engineering of the product are completed. This leads to easier scalability, standardization, lead-time reduction, and broadening the application area.
BibTeX:
@inproceedings{ISMB15_7,
  author = {Rafal P. Jastrzebski and Teemu Sillanpaa and Pekko Jaatinen and Alexander Smirnov and Jouni Vuojolainen and Tuomo Lindh and Antti Laiho},
  title = {Automated Design of AMB Rotor Systems with Standard Drive, Control Software and Hardware Technologies},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_7.pdf}
}
2016 Okada, Y., Touno, M., Matsuda, K.-I., Kondo, R. and Todaka, T. Six Pole type Hybrid Magnetic Bearing for Turbo-Machinery Proceedings of ISMB15  
Abstract: New six pole type hybrid magnetic bearing is introduced. It is intended to apply to high speed turbo-machinery. Traditionally turbo-machinery uses standard electro-magnet (EM) type active magnetic bearing (AMB) which requires PWM power amplifiers. Recently turbo manufacturer wants to develop their own magnetic bearing. Sometimes they are not accustomed with developing standard EM type magnetic bearings. The proposed magnetic bearing uses bias Permanent Magnet (PM), hence it is easily manufactured. The developed magnetic bearing also has good characteristics due to six directional control pole compared with the standard four directional control one.
BibTeX:
@inproceedings{ISMB15_70,
  author = {Yohji Okada and Masaki Touno and Ken-Ichi Matsuda and Ryou Kondo and Takashi Todaka},
  title = {Six Pole type Hybrid Magnetic Bearing for Turbo-Machinery},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_70.pdf}
}
2016 Vuojolainen, J., Smirnov, A., Jastrzebski, R., Sillanpaa, T., Ghalamchi, B. and Hartikainen, T. Updating the model of a rotor with surface mounted permanent magnets in an active magnetic bearing rotor system Proceedings of ISMB15  
Abstract: In this publication, the finite element method (FEM) model of a rotor of permanent magnet (PM) machine with surface mounted permanent magnets is updated. Typically rotors are modeled with FEM, but the model is still only an approximation of the real rotor. The rotor is constructed from number of different elements and have a complex geometry. Electrical machine part might have slits, surface mounted or embedded permanent magnets. Elements are often connected with shrink fits and this leads to the properties discrepancy compared to the elements described with Timoshenko beam theory. In the work, specific elements are selected as uncertain based on engineering experience and the elasticity values of these elements is updated. Experimental data is obtained with AMB system identification and then the frequency difference in the resonance and anti-resonance frequencies between the experimental data and FEM-model is minimized. When the frequency difference has been minimized, the updated FEM-model corresponds better to the experimental data. The updated model is utilized for controller synthesis procedure to improve performance of the control system. An AMB PM machine with surface mounted permanent magnets was used to test the rotor model update procedure. The procedure allowed to fit the model to the experimental data with accuracy of 56.57 %.
BibTeX:
@inproceedings{ISMB15_71,
  author = {Jouni Vuojolainen and Alexander Smirnov and Rafal Jastrzebski and Teemu Sillanpaa and Behnam Ghalamchi and Toni Hartikainen},
  title = {Updating the model of a rotor with surface mounted permanent magnets in an active magnetic bearing rotor system},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_71.pdf}
}
2016 Jiang, K. and Zhu, C. Parameter Identification for S tiffness and Damping in AMB-Flexible Rotor System Proceedings of ISMB15  
Abstract: To describe the support characteristic of an Active Magnetic Bearing(AMB) in rotor system via the traditional rotor dynamic theory, the equivalent stiffness and the equivalent damping are the frequently-used and important parameters. Some methods have been proposed for measuring the support parameters of AMB. However, most of them were based on the single degree of freedom(DOF) model or the multi-DOF rigid rotor model. In this study, a measuring method is proposed to identify the equivalent stiffness and the equivalent damping of the rotor radial support, which is employed in the flexible rotor system levitated on AMB. By means of the condensation of DOF in finite element rotor model, which includes the static force equivalence or the dynamic force equivalence, the whole rotor DOFs can be reduced to some certain DOFs and the number of the unknowns in the condensed model is decreased. The relation between the excitation and the response is extracted from the condensed rotor model. The identification equations are established in condition of the AMB excitation. By numerical simulation, the parameters of the equivalent stiffness and the equivalent damping of the AMB support are effectively identified and the possible problems are analyzed.
BibTeX:
@inproceedings{ISMB15_72,
  author = {Kejian Jiang and Changsheng Zhu},
  title = {Parameter Identification for S tiffness and Damping in AMB-Flexible Rotor System},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_72.pdf}
}
2016 Jeong, S. and Jeon, D. Rotordynamic Behavior and Rigid Mode Vibration Control by Hybrid Foil-Magnetic Bearing System Proceedings of ISMB15  
Abstract: In a hybrid foil-magnetic bearing (HFMB), an air foil bearing (AFB) serve as auxiliary bearings for an active magnetic bearing (AMB). This enables design simplification and weight reduction, and it can reduce the energy consumption of the AMB. Therefore, an HFMB has higher efficiency and reliability. This study conducts vibration control tests of an HFMB at increasing rotor speeds for various AMB control parameters. AMB control parameters are experimentally determined for achieving an appropriate load distribution between the AMB and the AFB. Furthermore, to minimize the vibration and energy consumption, the ON/OFF period control of the AMB is adjusted properly according to the operating speed. Accordingly, the HFMB can afford the high load capacity of the AFB at high speed as well as the high static stiffness to prevent initial rubbing and the control capability of the AMB to suppress excessive vibration. Therefore, the HFMB improves the performance of rotating machinery significantly in terms of range of operation and reliability. In addition, the effects of the load distribution between the AMB and the AFB are investigated by changing the control characteristics to produce different stiffness and damping effects. The HFMB for a high-speed rotor is experimentally optimized by altering the load distribution of the two bearings in terms of rigid mode vibration.
BibTeX:
@inproceedings{ISMB15_73,
  author = {Sena Jeong and Doyoung Jeon},
  title = {Rotordynamic Behavior and Rigid Mode Vibration Control by Hybrid Foil-Magnetic Bearing System},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_73.pdf}
}
2016 Caple, M., Maslen, E., Nagel, J. and Wild, J. Control of an AMB to Zero Static Force Proceedings of ISMB15  
Abstract: Someactivemagneticbearing(AMB)applicationsrequirethatthemean, orstaticforceexertedbytheAMBiszero. Examples include hybrid fluid film – AMB bearing pairings, rotor midspan dampers, and statically indeterminant systems with stiff rotors and more than two radial AMBs. When the position of the rotor relative to magnetic center is not known precisely, this zero force requirement can be hard to meet. A low frequency periodic biasing scheme is developed which enables a controller to detect non-zero static force by sensing rotor motion at the bias carrier frequency. A theoretical basis establishes feasibility but also the potential for coupling between control signals and the periodic bias. Simulation demonstrates that an ad–hoc bias adaptation scheme can successfully drive the static component to zero while permitting otherwise conventional control. The simulation results also show some spurious harmonic content associated with the sum and difference between a control signal frequency and the bias carrier frequency. Experimental results on a small, single DOF test rig further demonstrate the ability to drive the AMB static force to zero while adding damping to the system.
BibTeX:
@inproceedings{ISMB15_74,
  author = {Michael Caple and Eric Maslen and Jacquelyn Nagel and Jacob Wild},
  title = {Control of an AMB to Zero Static Force},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_74.pdf}
}
2016 Jarroux, C., Mahfoud, J., Dufour, R. and Defoy, B. On the dynamics of rotating machinery supported by AMB during base motion Proceedings of ISMB15  
Abstract: This study is devoted to rotor supported by Active Magnetic Bearings (AMBs) and subject to base motion. The machine casing is considered rigid and able to move along the 3 translations and the 3 rotations. The objective of this work is to assess the suitability of machine supported by AMBs to withstand base motions for applications such as compressors on FPSO (Floating production storage and offloading) or emergency steam turbines in nuclear plants. The model developed takes into account the base motion, unbalances on rotor, gravity and bearings properties. The consideration of the base motions has a significant impact on equations of motion and introduces parametric excitations. The centrifugal stiffening effect due to the base rotations is considered. The developed model, is compared with previous experiments performed with a light rotor mounted on classical ball- bearings. The dynamic behavior is analyzed for different types of base motion. Then, the capability of AMB to sustain base motions is examined. Numerical simulations are performed with a rigid rotor supported by two AMBs. The latter are controlled with an augmented PID not specifically tuned for base motion purpose. Finally, the results are discussed. The model developed is a first step for the improvement of turbomachinery supported by AMB. The aim is to eliminate a blocking point to the penetration of AMB technology in on board applications.
BibTeX:
@inproceedings{ISMB15_75,
  author = {Clement Jarroux and Jarir Mahfoud and Regis Dufour and Benjamin Defoy},
  title = {On the dynamics of rotating machinery supported by AMB during base motion},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_75.pdf}
}
2016 Li, K., Deng, Z., Liu, C., Zhou, J., He, J. and Ning, J. Unbalance Force Observer and Compensator of magnetic bearings supporting centrifugal compressor Proceedings of ISMB15  
Abstract: Magnetically suspended centrifugal compressors own unbalance forces in all degrees of freedom. The forces in radial directions are mainly derived from residual unbalance mass, and in axial directions are from shocking loads. These disturbances all can be observed using extended state observer, with which the unbalance forces can be compensated rapidly. In order to increase the precision of estimation and compensation, relevant parameters of magnetic bearings were theoretically and experimentally determined. The characteristics of the observer were studied through theoretical analysis and simulations. Additionally, a method, which can verify estimation accuracy was adopted in our research. At last, the unbalance force observation and compensation were realized on a suspended centrifugal compressor, which can be concluded that ESO owns fine disturbance rejection ability for active magnetic bearings.
BibTeX:
@inproceedings{ISMB15_76,
  author = {Kexiang Li and Zhiquan Deng and Chengzi Liu and Jie Zhou and Jiaxi He and Jiaqiang Ning},
  title = {Unbalance Force Observer and Compensator of magnetic bearings supporting centrifugal compressor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_76.pdf}
}
2016 Wellerdieck, T. and Nussbaumer, T. Experimental Verification of a Model-Based Zero and Low-Speed Angle Observer for Bearingless Permanent Magnet Machines Proceedings of ISMB15  
Abstract: Bearingless machines are used for a variety of applications with demand for low mechanical loss, low wear and low contamination. These machines use contact-free magnetic suspension to levitate the rotor. The control of the machine requires precise radial and angular position information in order to ensure stable levitation. This informa- tion is usually obtained with two types of sensors: radial displacement sensors and angle sensors. Alternatively, an angle-sensorless control scheme can be used, reducing the complexity and the cost of the machine. While such a control is well known for conventional machines it is challenging to adapt it for bearingless machines. The reason is that most methods fail to provide the angle information at zero- and low-speed but bearingless machines require knowledge about the rotor angle at all speeds in order to function. The theoretical mode of operation of a model-based angle observer for zero- and low-speed operation of a bear- ingless machine was shown in previous publications. The observer obtains the rotor angle estimation error by analyzing the performance of the radial bearing and comparing it to the performance of a model with zero angle error. This observer can be used at zero- and at low-speeds. This paper provides a more detailed description of the non-idealities of the zero- and low-speed observer and presents new results of machine operation without angle sensors. The generation of torque and force inside the machineisanalyzedinmoredetail. Theexperimentallyverifiedresultsofthispaperindicatethatthenovelobserver can be used up to speeds at which back-electromotive force estimation is possible.
BibTeX:
@inproceedings{ISMB15_77,
  author = {Tobias Wellerdieck and Thomas Nussbaumer},
  title = {Experimental Verification of a Model-Based Zero and Low-Speed Angle Observer for Bearingless Permanent Magnet Machines},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_77.pdf}
}
2016 Mukherjee, V., Manninen, A. and Pippuri, J. Analysis of Electromagnetic Force Ripple on the Rotor of a Bearingless Synchronous Reluctance Motor Proceedings of ISMB15  
Abstract: This paper presents the analysis of electromagnetic forces on the rotor of a synchronous reluctance motor under self-levitation operation. Due to the presence of flux barriers, the ripple content in the torque and levitation force brings a major concern. Different schemes of torque ripple reduction have been taken as a reference and their effects on the levitation forces are investigated. The paper explores the advantages and disadvantages of rotor skewing, stator winding chording and asymmetric flux barrier design on the levitation forces. Finite element analysis has been used with current source, and the computations are performed by the angular sweep of the rotor varying with time. Skewing helps to damp the slot harmonic when the rotor is skewed for one slot pitch. Multi-slice model has been used to determine the skewing effect. A significant improvement in the reduction of levitation force ripple has been observed when the rotor is skewed. The chording slightly reduces the levitation force ripple. The asymmetric flux barrier design shows improvement in the reduction of torque ripple, however the levitation force has additional harmonics due to the asymmetry which is not a good option when used for the bearingless motor operation.
BibTeX:
@inproceedings{ISMB15_78,
  author = {Victor Mukherjee and Aino Manninen and Jenni Pippuri},
  title = {Analysis of Electromagnetic Force Ripple on the Rotor of a Bearingless Synchronous Reluctance Motor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_78.pdf}
}
2016 Osa, M., Masuzawa, T., Saito, T. and Tatsumi, E. Magnetic Levitation Performance of Miniaturized Magnetically Levitated Motor with 5-DOF Active Control Proceedings of ISMB15  
Abstract: Mechanical circulatory support (MCS) therapy plays a significant role in an alternative therapy of heart transplants for pediatric heart disease patients. However, technical difficulties, such as high durability, better blood compatibility and miniature device size, prevent the pediatric MCS device development. In this study, a double stator axial gap maglev motor for pediatric MCS device has been developed. The maglev motor has two identical motor stators, and a levitated rotor impeller which is aligned between the stators. The levitated rotor impeller is fully suspended with 5-degrees of freedom (5-DOF) active control. A miniaturized maglev motor is designed and developed based on FEM magnetic field analysis for use in implantable ventricular assist devices (VADs). The developed maglev motor has an outer diameter of 22 mm and a length of 33 mm. This paper is an initial report on the magnetic levitation and rotation performance of the miniaturized maglev motor. The levitated rotor impeller is magnetically levitated and rotated with the 5-DOF active control. The oscillation amplitudes (x, y and z) and inclination angles (θx and θy) of the levitated rotor impeller are then evaluated in both air and water. The developed maglev motor achieves non-contact rotation up to 1600 rpm in air and 4500 rom in water, respectively. The oscillation amplitudes and inclination angles are sufficiently suppressed in water due to fluid damping. The developed maglev motor indicates potential to achieve the practical use of maglev rotatory pediatric VAD.
BibTeX:
@inproceedings{ISMB15_79,
  author = {Masahiro Osa and Toru Masuzawa and Takuya Saito and Eisuke Tatsumi},
  title = {Magnetic Levitation Performance of Miniaturized Magnetically Levitated Motor with 5-DOF Active Control},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_79.pdf}
}
2016 Zhou, Y., Mo, N., Yang, G., Shi, Z. and Zhao, L. The Electro Magnetic Compatibility Analysis and Experiment of the electronic system in AMB Proceedings of ISMB15  
Abstract: The helium turbine and generator system of 10MW high-temperature gas-cooled reactor (HTR-10GT) is constructed by the Institute of Nuclear and New Energy Technology (INET) at Tsinghua University of China. One of key technologies is the use of active magnetic bearings (AMB) as support member. The turbine has a special structure, thin and long rotor, speed up to 15000rpm, and have to pass a second bending critical. Since the harsh condition, the AMB system need not only precise control but also high reliability, to resist the terrible environment in the reactor. Through analysis, the reliability of the electronic system is the weakest link in AMB. And the radiation interference from bearing coil and conducted interference from the power amplifier are the main noise source. With modelling and analysis, find out the conductive interference play an important role on the electronic system, while the radiation interference can be ignore by the sensor’s special structure. According to the results, Electro Magnetic Susceptibility (EMS) tests was designed and were done on the electronic system. Unfortunately, the electronic system could not pass all the EMS testing at first time. Then, the optimization on hardware and software for electronic system are shown in the paper. It is these improvements, the system passed the EMS final test successfully, and operating in the field stably now. This article combined with theoretical analysis and practical experiment, not only demonstrates the importance of the electronic system’s reliability, but also gives effective improvement methods. It can be said has engineering significance especially for HTR- 10GT spreading.
BibTeX:
@inproceedings{ISMB15_8,
  author = {Yan Zhou and Ni Mo and Guojun Yang and Zhengang Shi and Lei Zhao},
  title = {The Electro Magnetic Compatibility Analysis and Experiment of the electronic system in AMB},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_8.pdf}
}
2016 Jiang, C., Andou, K. and Ueno, S. 5-Degree of Freedom Active Position Control of an Axial Self-bearing Motor with Six Concentrated Stator Windings Proceedings of ISMB15  
Abstract: In recent years, pumps of magnetic bearing type have been widely developed because that a magnetic bearing motor need not lubrication oil and has no friction loss. For downsizing and reducing cost of magnetic bearings, an axial self-bearing motor (ASBM) is developed in this paper. The ASBM is composed of two identical stators and on disk rotor which is sandwiched by the stators axially. Each stator has six concentrated winding coils which are driven by separate power amplifiers. Based on control principle of the developed ASBM, 5-degree of freedom (5-DOF) active position control system is designed to realize axial control, tilt control and radial control simultaneously. For generating rotation torque, open-loop torque control method and closed-loop torque control method are applied, respectively. After implementing the above mentioned control method, experimental results of rotation test are shown to verify the practicability of the developed ASBM and effectiveness of the designed control system.
BibTeX:
@inproceedings{ISMB15_80,
  author = {Changan Jiang and Kazuaki Andou and Satoshi Ueno},
  title = {5-Degree of Freedom Active Position Control of an Axial Self-bearing Motor with Six Concentrated Stator Windings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_80.pdf}
}
2016 Anta, A., Selga, R.C., Osama, M. and Alban, T. System Identification for Active Magnetic Bearings at Nonzero Speeds Proceedings of ISMB15  
Abstract: In this paper we consider the problem of obtaining a dynamic model of rotating machinery equipped with magnetic bearings for a given speed range. Theoretical models are typically not accurate enough and cannot be trusted to predict system behaviour for the whole operating range of the machine. In this work we first obtain a dynamic model of the system at several speed levels; second, an extrapolation/interpolation of these models is performed to produce an estimate of the behaviour for the whole speed range. This procedure overcomes two common issues in system identification for magnetic bearings: first, it is costly and time-consuming to perform system identification at many speed levels to cover the whole operating range. Second, it is typically not safe to reach certain speeds unless the stability and unbalance response at high speeds has been verified. This can be only done once a reliable model is available. From a technical perspective, our approach relies on local system identification techniques aimed at linear parameter varying (LPV) systems. Compared to existing work, we believe the main contributions of this work are: we do not rely on global approaches that might lead into nonconvex problems, our approach is amenable to automation, and it allows considering the presence of casing modes in the system.
BibTeX:
@inproceedings{ISMB15_81,
  author = {Adolfo Anta and Rosa Castane Selga and Mohamed Osama and Thomas Alban},
  title = {System Identification for Active Magnetic Bearings at Nonzero Speeds},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_81.pdf}
}
2016 Vuojolainen, J., Jastrzebski, R. and Pyrhonen, O. Using a pseudorandom binary sequence for rotor-bearing system identification in active magnetic bearing rotor systems Proceedings of ISMB15  
Abstract: This paper examines usage of a pseudorandom binary sequence (PRBS) in system identification of the rotor- bearing system in active magnetic bearings (AMBs). In the work, PRBS system identification is compared with adaptive amplitude stepped sine identification. PRBS is a deterministic, periodic signal varying between two levels. A stepped sine wave is a type of sine wave that has all the energy on one frequency only. The paper compares the running time, memory consumption and accuracy of the identification methods studied. A five degree-of-freedom (DOF) AMB testrig is used to test the accuracy of the stepped sine and PRBS system identification approaches. Both methods are implemented in a real-time open automation system. Required running time of the PRBS identification was significantly shorter than that of the stepped sine identification, but more memory was needed for data points. The accuracy of both identification methods was similar at lower frequencies, but at higher frequencies there was greater fluctuation with PRBS identification than when using the stepped sine method. The results show the suitability of using a PRBS in AMB rotor-bearing system identification. The PRBS based approach would be the choice for initial fast identifications of the system, while the stepped sine method would remain as the choice when focusing on identification at specific and higher frequencies.
BibTeX:
@inproceedings{ISMB15_82,
  author = {Jouni Vuojolainen and Rafal Jastrzebski and Olli Pyrhonen},
  title = {Using a pseudorandom binary sequence for rotor-bearing system identification in active magnetic bearing rotor systems},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_82.pdf}
}
2016 Voigt, A.J., Lauridsen, J., Mandrup-Poulsen, C. and Nielsen, K.K. Identification of Parameters in Active Magnetic Bearing Systems Proceedings of ISMB15  
Abstract: A method for identifying uncertain parameters in Active Magnetic Bearing (AMB) based rotordynamic systems is intro- duced and adapted for experimental application. The Closed Loop Identification (CLI) method is utilised to estimate the current/force factors K_i and the displacement/force factors K_s as well as a time constant tau_e for a first order approxima- tion of unknown actuator dynamics. To assess the precision with which CLI method can be employed to estimate AMB parameters the factors K_i , estimated using the CLI method, is compared to K_i factors attained through a Static Loading (SL) method. The CLI method and SL method produce similar results, indicating that the CLI method is able to perform closed loop identification of uncertain AMB parameters.
BibTeX:
@inproceedings{ISMB15_83,
  author = {Andreas Jauernik Voigt and Jonas Lauridsen and Christian Mandrup-Poulsen and Kenny Krogh Nielsen},
  title = {Identification of Parameters in Active Magnetic Bearing Systems},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_83.pdf}
}
2016 Gavrilenko, O., Sattel, T. and Reger, J. Identification of Active Magnetic Bearing Systems Utilizing a Modulating Function Technique Proceedings of ISMB15  
Abstract: An application of modulating function (MF) technique to the direct closed-loop identification for the estimation of a continuous-time model of multi-input-multi-output magnetic bearing system from sampled data are presented in this paper. The plant description given as a differential matrix polynomial is transformed into a matrix of difference equations using the modulating function approach, which allows to avoid numerical problems by aproximating time derivatives. Additionally, the initial conditions can be neglected as a characteristic of the MF technique. The system parameter estimation represents a solution of a least-squares problem derived from the difference system model with experimental data from an industrial magentic bearing system.
BibTeX:
@inproceedings{ISMB15_84,
  author = {Olga Gavrilenko and Thomas Sattel and Johann Reger},
  title = {Identification of Active Magnetic Bearing Systems Utilizing a Modulating Function Technique},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_84.pdf}
}
2016 Xu, Y., Zhou, J., Jin, C. and Xu, L. Identification of speed-dependent active magnetic bearings dynamic parameters in aflexible rotor system Proceedings of ISMB15  
Abstract: Active magnetic bearings (AMBs) support rotors using electromagnetic force rather than mechanical force. It is necessary to accurately identify AMBs force coefficients (equivalent stiffness and damping) since they play a key role in the rotordynamic analysis. The identification is usually performed by analyzing the unbalance response; however, the unknown residual unbalances will decrease the identification accuracy and rigid rotor model is only available when the rotating speed is far below the bending critical speed. To address the above issues, this paper proposes an identification algorithm to estimate the stiffness and damping parameters of a flexible rotor AMBs system using two independent unbalance response data. The proposed algorithm is employed for experimental identification for a flexible rotor AMBs system ranging from 3,000 rpm (50 Hz) to 30,000 rpm (500 Hz).
BibTeX:
@inproceedings{ISMB15_85,
  author = {Yuanping Xu and Jin Zhou and Chaowu Jin and Longxiang Xu},
  title = {Identification of speed-dependent active magnetic bearings dynamic parameters in aflexible rotor system},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_85.pdf}
}
2016 Bahr, F., Moench, I., Ernst, D., Zerna, T. and Schmidt, O.G. Direct Field Control of AMBs using Flux Feedback based on Integrable Hall Sensors Proceedings of ISMB15  
Abstract: Within the last years magnetic bearing technology has been pushed by a significant upturn in oil & gas industry as well as in machining applications. Nowadays, specific high speed spindles are equipped with industrially standardized active magnetic bearing systems (AMB) allowing for highly precise rotor positioning due to their contact-free and low-maintenance operation. However, compared to conventional ball bearings well-established AMB systems are limited by their relatively low stiffness. In order to improve dynamic performance flux based control algorithms are under investigation for the last decades already. The main challenge is how to integrate commercially available magnetic field sensors into typical AMB air gaps. Within this research ultra-thin and flexible Bismuth Hall sensors with a total thickness of less than 100 µm were developed and integrated into an actively controlled magnetic suspension system. For the first time an AMB control using the direct feedback of bendable Bismuth sensors was implemented and its operational capability for accurate rotor positioning was demonstrated successfully and investigated by frequency response analysis.
BibTeX:
@inproceedings{ISMB15_86,
  author = {Falk Bahr and Ingolf Moench and Daniel Ernst and Thomas Zerna and Oliver G. Schmidt},
  title = {Direct Field Control of AMBs using Flux Feedback based on Integrable Hall Sensors},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_86.pdf}
}
2016 Gerami, A. and Fittro, R. Modeling and Control of Magnetic Bearings With Nonlinear Magnetization (Simulation vs. Experiment) Proceedings of ISMB15  
Abstract: This paper is a continuation of the work presented in (Gerami,,et al., 2015), which explored the use of the Lur’e formulation to achieve increased dynamic load capacity in active magnetic bearings (AMBs). The increase in the load capacity was achieved by developing a nonlinear model that enabled the system to operate in the nonlinear region of the magnetization curve. While the previous work focused on the theoretical development of the modeling and control approach, this paper verifies the results by experiments conducted on a rocking beam test rig. The experiment demonstrates that the proposed modeling and control approach significantly improves the transient response and disturbance rejection capabilities of the magnetic bearing system compared with present industrial practice. Based on the excellent agreement between simulation and experimental results, it is shown that existing industrial AMBs could be modified to be significantly more resilient to unknown external disturbances, and therefore result in fewer shutdowns and less associated damage to backup bearings. In addition, for new AMB applications, smaller AMBs could be designed using this method which would be able to handle the same worst-case disturbance forces as larger AMB systems based on standard modeling and control methods.
BibTeX:
@inproceedings{ISMB15_87,
  author = {Ali Gerami and Roger Fittro},
  title = {Modeling and Control of Magnetic Bearings With Nonlinear Magnetization (Simulation vs. Experiment)},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_87.pdf}
}
2016 Filatov, A., Hawkins, L. and Ukidve, C. Bias Flux Compensation in the 'Side-By-Side' Combination Radial/Axial Homopolar PM-Biased Active Magnetic Bearing Proceedings of ISMB15  
Abstract: ‘Side-By-Side’ (SBS) Combination Radial/Axial Homopolar PM-Biased Active Magnetic Bearing design has been demonstrated to be an attractive solution for many applications requiring magnetic bearings. One of the key parts of this design is a bias flux compensation coil, which is needed to maintain a constant bias flux level under various axial loads and positions of the rotor. This is important, because variations in the bias flux in the SBS combo bearing affect operating parameters of both the radial and axial channels, including actuator gains and negative stiffnesses. Besides complicating the controls, changes of the bias flux may result in losses of the load capacities, which cannot be recovered thru improving the control algorithms. Previously, the results of testing a standalone SBS combo bearing on a test rig have been presented. These included demonstrations of the effectiveness of the compensation for the effects of the axial control current on the overall bias flux. Those results showed good agreement with theoretical predictions, however, no analytical details of the compensation coil operation were given. The current paper presents the theoretical basis of the bias flux compensation. In addition, effects of the bias flux compensation on the properties of the magnetic suspension are demonstrated using a fully operational machine – a 200kW power range turbocompressor equipped with a SBS combination bearing.
BibTeX:
@inproceedings{ISMB15_88,
  author = {Alexei Filatov and Larry Hawkins and Chinmay Ukidve},
  title = {Bias Flux Compensation in the 'Side-By-Side' Combination Radial/Axial Homopolar PM-Biased Active Magnetic Bearing},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_88.pdf}
}
2016 Osako, K. and Sakamoto, T. Duality parameter of Approximate Dual Control for Electromagnetic Suspension Proceedings of ISMB15  
Abstract: In dual control, the control input has a dual role so that the system with uncertain parameters should be controlled carefully while obtaining quality system information to identify. This paper deals with the effects of our approximate method of dual control on the performance of electromagnetic suspension system. This method compensates a weakness of model predictive control which requires an accuracy system model. The performance weight between the control and the identification is formulated by a single design parameter. We show simulations when varying the design parameter of magnitude of excitation in order to study the effects on the control and identification result.
BibTeX:
@inproceedings{ISMB15_89,
  author = {Kento Osako and Tetsuzo Sakamoto},
  title = {Duality parameter of Approximate Dual Control for Electromagnetic Suspension},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_89.pdf}
}
2016 Gruber, W. and Silber, S. 20 Years Bearingless Slice Motor - its Developments and Applications Proceedings of ISMB15  
Abstract: Bearingless slice motors are very compact and cost effective systems that allow full magnetic levitation in all degrees of freedom. Due to the disc shaped rotor, tilting and axial position are passively stabilized by the permanent magnetic biased air gap field, whereas the radial position and the rotor speed are actively controlled. This paper summarizes the continuous development in the field of bearingless slice motors ongoing for over 20 years. Different implemented topologies are outlined and basic characteristic values are compared. Such an extensive overview will help to show general trends, limits and capabilities of bearingless slice motors and their applicability in industry and academia.
BibTeX:
@inproceedings{ISMB15_9,
  author = {Wolfgang Gruber and Siegfried Silber},
  title = {20 Years Bearingless Slice Motor - its Developments and Applications},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_9.pdf}
}
2016 Basovich, S., Menaker, Y. and Arogeti, S. Precision Positioning Oriented Modeling of Electromagnetic Actuator Proceedings of ISMB15  
Abstract: This article presents a novel approach for accurate modeling of the relation between force, electric current and the actual air gap in the electromagnetic actuator used in active magnetic bearings (AMB) based precision positioning systems. The novelty of the presented modeling approach lies in a newly derived correlation for the relative permeability term in the electromagnetic actuator force model. This correlation, which can be easily obtained using the B-H curve for a given low-hysteresis actuator core material, describes the relative permeability term by means of electric current, actual air gap and a few parameters of the actuator. The resulting actuator model, which can be used either for more correct implementation of the well-known feedback-linearization technique or for obtaining more reliable results in simulations, was validated experimentally using a real single-degree-of-freedom (S-DoF) AMB plant.
BibTeX:
@inproceedings{ISMB15_90,
  author = {Sergei Basovich and Yonattan Menaker and Shai Arogeti},
  title = {Precision Positioning Oriented Modeling of Electromagnetic Actuator},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_90.pdf}
}
2016 Onuma, H., Masuzawa, T. and Murakami, M. Development of Radial Type Self-Bearing Motor for Small Centrifugal Blood Pump Proceedings of ISMB15  
Abstract: A small magnetic levitated centrifugal blood pump using a radial type self-bearing motor has been developed for use as an implantable artificial heart. In order to realize an implantable small centrifugal blood pump for a small adult patient, miniaturization and high efficiency of the device are necessary. In this study, a radial type self-bearing motor which is small-diameter and thin was developed, and magnetic suspension characteristics were measured. And, a magnetic levitated centrifugal blood pump using the self-bearing motor was developed, and pump performance and levitation performance were measured. In the self-bearing motor, the plus minus two-pole algorithm is adopted to levitate and rotate the rotor. The plus two-pole algorithm type and the minus two-pole algorithm type were developed to compare the magnetic suspension force in the radial direction. The minus two-pole algorithm type had very good control ability in the radial direction. The passive stability performance in the axial direction was enough ability to suspend the rotor-impeller. The restoring force was possible to be varied by the rotation magnetic field. At the operating condition with a flow rate of 5 L/min against a pressure of 100 mm Hg, the oscillation amplitude in x, y, z direction were 0.014 mm, 0.014 mm and 0.039 mm, respectively. And, the total power consumption was 7.1 W. The developed small magnetic levitated centrifugal blood pump has demonstrated sufficient levitation performance and low total power consumption. The average displacement in z direction of the rotor-impeller was possible to change by changing the phase angle of the rotational magnetic field.
BibTeX:
@inproceedings{ISMB15_91,
  author = {Hiroyuki Onuma and Toru Masuzawa and Michiko Murakami},
  title = {Development of Radial Type Self-Bearing Motor for Small Centrifugal Blood Pump},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_91.pdf}
}
2016 Takeda, R., Ueno, S. and Jiang, C. Development of a Centrifugal Cryogenic Fluid Pump using an Axial Self-bearing Motor Proceedings of ISMB15  
Abstract: This paper proposes a new centrifugal cryogenic fluid pump. It employs an axial self-bearing motor (ASBM), a superconducting magnetic bearing (SMB), and a passive magnetic bearing (PMB). As the device does not require seal material and bearing, it has the advantages of long life, no risk of leakage of cryogenic fluid, and no maintenance. The ASBM in this device can control the axial position and rotation torque of the rotor. In detail, PID controllers control axial position, and an open-loop torque control method generates rotation torque. The shaft is supported by PMB and SMB in the radial direction. Liquid nitrogen is injected into the device to cool the superconducting magnetic bearing. The impeller transports the LN2. A flying test, a rotation test in air or water, and a rotation test with SMB are carried out. When the rotation test is conducted without water, a rotation speed of up to 1300 rpm is observed. When the rotation test is conducted with water, a rotation speed of 600 rpm was observed.
BibTeX:
@inproceedings{ISMB15_92,
  author = {Ryo Takeda and Satoshi Ueno and Changan Jiang},
  title = {Development of a Centrifugal Cryogenic Fluid Pump using an Axial Self-bearing Motor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_92.pdf}
}
2016 Mitterhofer, H. and Jungmayr, G. Stability improvement of passively stabilized degrees of freedom in magnetically levitated systems Proceedings of ISMB15  
Abstract: The passive degrees of freedom of magnetically levitated devices are prone to external disturbance forces and torques as there is no possibility to adapt the bearing stiffness or to introduce damping actively. In the case of bearingless disk drives, this concerns the axial and tilt deflections. A novel stabilization coil presented in this work helps to stabilize the tilt deflections. After the introduction of the electrodynamic working principle, the measurement results conducted at a high speed bearingless disk drive prototype are presented. To the knowledge of the authors, this work represents the first publication on such a stabilization device.
BibTeX:
@inproceedings{ISMB15_93,
  author = {Hubert Mitterhofer and Gerald Jungmayr},
  title = {Stability improvement of passively stabilized degrees of freedom in magnetically levitated systems},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_93.pdf}
}
2016 Cui, Q., Impinna, F., Detoni, J.G., Amati, N., Tonoli, A. and Bleuler, H. Dynamic Characterization of Electrodynamic Bearings Combined with Active Magnetic Dampers Proceedings of ISMB15  
Abstract: Electrodynamic Bearings (EDBs) are a kind of passive magnetic bearings that exploits the interaction between the eddy currents in a rotating conductor and the stationary magnetic field to provide restoring forces. They have been regarded as an appealing alternative to Active Magnetic Bearings (AMBs), having the possibility to obtain stable levitation using standard conductive materials at room temperature without introducing negative stiffness in any direction. Compared to AMBs, EDBs present advantages such as lower cost, higher reliability due to simplicity of configurations. However, applications of EDBs are still limited due to instability issues. The rotating damping force arising in EDBs causes unstable behavior of the rotor, which requires a stabilizing solution. A hybrid solution is presented in the present paper, where Active Magnetic Dampers (AMDs) are applied to provide non-rotating damping to the rotor supported by EDBs to obtain stable operation. This solution is designed to exploit the high reliability of EDBs, overcoming the stability problem by means of controllable AMDs. Rather than using active electromagnetic actuators to provide stiffness (like in standard AMBs), the AMBs here are used as dampers only (thus called AMDs), resulting in downsized and more efficient AMBs. The effect of the EDB−AMD system has been studied both analytically and experimentally. A dedicated test rig has been built to validate the analytical model and to characterize the system. Dynamic characterization of the system is presented, demonstrating the effectiveness of this solution and dynamics of the system.
BibTeX:
@inproceedings{ISMB15_94,
  author = {Qingwen Cui and Fabrizio Impinna and Joaquim Girardello Detoni and Nicola Amati and Andrea Tonoli and Hannes Bleuler},
  title = {Dynamic Characterization of Electrodynamic Bearings Combined with Active Magnetic Dampers},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_94.pdf}
}
2016 Liu, S. An Axial flow blood pump with magnetic fluid mixed support Proceedings of ISMB15  
Abstract: In this paper, the axial flow blood pump with magnetic-fluid support is presented. With the goal that the implanted blood pump should have the advantages of small volume, light weight and low power consumption, we studied the blood pump structure with permanent radial magnetic bearings and axial fluid-film bearing, designed and calculated the relationship between impeller and blood flow, finally gave the analysis of power calculation. The axial flow blood pump with magnetic fluid mixed support is presented. The motor rotor is supported by 2 radial PM bearings. The assembly of the motor stator and the PM bearing stators is supported (or clamped in place) inside of the 4-blade diffuser. The motor wirings will go through the diffuser vanes. In this paper, two radial bearings are used in the Halbach structure design of the full permanent magnet, and the electromagnetic field simulation is carried out by using the finite element method. The results show that the permanent magnetic bearing of the structure increases the bearing capacity, and reduces the power consumption. In this paper, the total power loss of the blood pump is not more than 10W, and the weight is about 225 grams. The results show that the blood pump with magnetic fluid mixed support can achieve the purpose of reducing power loss and reducing the volume.
BibTeX:
@inproceedings{ISMB15_95,
  author = {Shuqin Liu},
  title = {An Axial flow blood pump with magnetic fluid mixed support},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_95.pdf}
}
2016 Fonseca, C.A., Santos, I. and Weber, H. Influence of Unbalance Levels on Nonlinear Dynamics of a Rotor-Backup Rolling Bearing System Proceedings of ISMB15  
Abstract: Rotor drops in magnetic bearing and unbalance in rotors have been objective of study for many years. The com- bination of these two well-known phenomena led to an interesting chaotic response, when the rotor touches the inner race of the back-up bearing. The present work explores the nonlinear rotor-backup-bearing dynamics both theoretically and experimentally using a fully instrumented test rig, where the position of shaft, its angular velocity and the contact forces between the shaft and the backup bearing are sampled at 25 kHz. The test rig is built by a removable passive magnetic bearing, which allows for simulation of magnetic bearing failure (loose of carrying capacity and rotor fall). A theoretical approach is given beforehand and supplies the basis of the study. Finally the presented results are commented on the point of view of nonlinear dynamics applied to the practical use. The theoretical and numerical analyzes are shown through Poincaré maps and double sided spectrum. The latter is important to characterize the condition at different levels of unbalance between forward of backwards whirl. Our preliminary results indicate that for small levels of unbalance the rotor oscillates at the bottom of the backup bear- ing. When the levels of unbalance increase, the dynamical behaviour of the rotor changes, leading to extremely harmful conditions, since the rotor can be lifted from the bottom of the bearing (contact state) and return, starting to impact on the backup inner race innumerable times without reaching a steady state.
BibTeX:
@inproceedings{ISMB15_96,
  author = {Cesar Augusto Fonseca and Ilmar Santos and Hans Weber},
  title = {Influence of Unbalance Levels on Nonlinear Dynamics of a Rotor-Backup Rolling Bearing System},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_96.pdf}
}
2016 Keogh, P.S. and Cole, M.O.T. Dynamic Conditions to Destabilize Persistent Rotor/Touchdown Bearing Contact in AMB Systems Proceedings of ISMB15  
Abstract: It is now common practice to supplement a magnetic bearing with a touchdown bearing to protect the rotor and stator components. Rotor/touchdown bearing contact may arise from rotor drop, caused by power loss or emergency shutdown. This paper considers the control options that are viable when the magnetic bearing is still functional should contact may arise from intermittent faults or overload conditions. The problem is that bi-stable rotor responses are possible, with and without contact. If rotor contact should become persistent, the desirable course of action is to destabilize the rotor response and induce a return to contact-free levitation. In order to achieve this, it is appropriate to gain an understanding of the rotor dynamic behavior. This is determined from analytical and simulated results to reveal suitable control actions. These may be applied through the magnetic bearing control system, or by activating the touchdown bearing through a separate control loop. The issue is that standard control action for a contact-free rotor state will not be appropriate for a rotor in persistent contact since the basic plants to be controlled are significantly different. The required control action must be activated only when contact is detected. The results demonstrate that appropriately phased synchronous forcing could destabilize synchronous forward rub responses. Alternatively, small whirl motions of a touchdown bearing could also be beneficial without disturbing the main magnetic bearing control loop.
BibTeX:
@inproceedings{ISMB15_97,
  author = {Patrick Sean Keogh and Matthew Owen Thomas Cole},
  title = {Dynamic Conditions to Destabilize Persistent Rotor/Touchdown Bearing Contact in AMB Systems},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_97.pdf}
}
2016 Hawkins, L., Wang, Z. and Wadhvani, V. Transient Simulation of Magnetic Bearing and Backup Bearing Interaction in a High Speed Rotary Atomizer Subjected to Impulsive Loads Proceedings of ISMB15  
Abstract: A high speed rotary atomizer supported by active magnetic bearings (AMB) has been in service in a pharmaceutical-processing plant for over three years. This process challenges the AMBs by imposing variable, quasi-periodic external impulses on the atomizer. The impulses are occasionally large enough to overload the AMBs, resulting in backup bearing contact during operation. Implementation of a novel impulse detection and Impulse Recovery Compensator (IRC) introduced to allow continuous operation has been previously reported. In this work, a transient, nonlinear rotordynamic simulation of the atomizer, together with field measured position and current time histories, is used to help characterize the impulsive loads, the magnetic bearing control response and backup bearing reaction loads. The simulation results provide a reasonable match to field measured position and current time histories when the impulse load is produced by a sudden large unbalance, temporary or permanent. The simulation correctly predicts that amplifier saturation is relieved and the rotor re-levitates when the control is switched to the IRC. Predicted backup bearing loads during whirl are reasonable and subsequently calculated stress levels are consistent with favorable inspections of backup bearings removed from service. Future work with the simulation will include further improvements to the amplifier and backup bearing modelling.
BibTeX:
@inproceedings{ISMB15_98,
  author = {Larry Hawkins and Zhiyang Wang and Vishal Wadhvani},
  title = {Transient Simulation of Magnetic Bearing and Backup Bearing Interaction in a High Speed Rotary Atomizer Subjected to Impulsive Loads},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_98.pdf}
}
2016 Gouws, J.M. and Rensburg, J.J.V. An Investigation into Backup Bearing Life using Quantified Rotor Delevitation Severity Indicators Proceedings of ISMB15  
Abstract: Safe and continuous operation of an active magnetic bearing (AMB) system relies heavily on its mechanical, electronic and software components. If one of these components fail, a rotor delevitation event (RDE) could be induced and possibly damage the backup bearing (BB) system. To improve BB reliability and safety, the usability of delevitation severity indicators (DVAL, VVAL and AVVAL) for predicting BB life is investigated. A small-scale active magnetic bearing system is used to generate BB degradation data by subjecting steel-caged rolling-element bearings to multiple RDEs. The RDEs are induced at specific initial conditions to analyze the statistical distribution of bearing failure. Delevitation severity indicators are subsequently used to compare a series of RDEs to find changes in BB performance characteristics. Using only shaft position and rotating speed data, this investigation showed that delevitation severity indicators change as the bearing degrades. A distinctive linear pattern of degradation is identified by calculating AVVAL for the duration when rotor whirl and bouncing occur. This linear degradation pattern is used to identify a failure zone wherein the probability of bearing failure is extremely high. A BB life prediction method based on this linear degradation pattern and AVVAL is developed and validated.
BibTeX:
@inproceedings{ISMB15_99,
  author = {Jacob Marthinus Gouws and Jan Janse Van Rensburg},
  title = {An Investigation into Backup Bearing Life using Quantified Rotor Delevitation Severity Indicators},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_99.pdf}
}
2015 Pilat, A.K. Study on electromagnetic force in conical axial magnetic bearing Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: This paper presents two models of a single coil cylindrical electromagnet with a conical shape. The point of interest is focussed on the electromagnetic force, features and limitations of a such models. The calculations were realised with the support of COMSOL Multiphysics software. The 3D models allowed to expand knowledgebase about the electromagnetic force components not visible in the 2D axisymmetry mode.
BibTeX:
@inproceedings{WMLT10_1,
  author = {A. K. Pilat},
  title = {Study on electromagnetic force in conical axial magnetic bearing},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_1.pdf}
}
2015 Rudolph, J. and Werner, R. Untersuchungen an einem streuflussbasierten Messsystem zur Bestimmung der Wellenposition Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: Dieser Beitrag beschreibt das Betriebsverhalten von Magnetfeldsensoren, mit denen die Position der Welle im Magnetlager durch Auswertung der magnetischen Streuflüsse bestimmt werden kann. Es werden Untersuchungen zum thermischen sowie zum frequenzabhängigen Übertragungsverhalten der Sensoren vorgestellt. Weiterhin wird eine Vorrichtung zur Kalibrierung der Sensoren beschrieben und abschließend ein verbessertes Verfahren zur Kompensation der durch Steuerströme verursachten Einflüsse vorgestellt.
BibTeX:
@inproceedings{WMLT10_10,
  author = {J. Rudolph and R. Werner},
  title = {Untersuchungen an einem streuflussbasierten Messsystem zur Bestimmung der Wellenposition},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_10.pdf}
}
2015 Li, L. Experimentelle Untersuchung des Konzeptes adaptiver Zustandsregelung anhand Parameteridentifikation Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: Magnetlager können nicht nur Verschleiß- und Lebensdauerprobleme, sondern auch Rauschprobleme, lösen. Die Störungen auf das System und die Variation der Systemeigenschaften beeinflussen die Funktionalität. Eine Zustandsregelung zeigt Vorteile in der Regelqualität. Die Nichtlinearitäten und die Parameterunsicherheiten der aktiven Magnetlager machen eine optimale Regelung schwer. Die Arbeit präsentiert eine Methode der adaptiven Zustandsregelung mit Nutzung des Softcomputing. Zuerst wird ein Kalmanfilter entwickelt, um Zustandsgrößen erfassen zu können. Danach wird ein Systemmodell auf Basis der Fuzzylogik erstellt. Ziel ist es, die Nichtlinearitäten und Parameterunsicherheiten im Modell zu berücksichtigen. Zuletzt wird eine adaptive Zustandregelung entwickelt, damit wird eine optimale Regelung für jeden aktuellen Arbeitspunkt ermöglicht. Weiterhin werden in einer experimentellen Untersuchung die Vorteile des neuen Konzeptes gegenüber dem traditionellem Zustandsregler nachgewiesen.
BibTeX:
@inproceedings{WMLT10_11,
  author = {L. Li},
  title = {Experimentelle Untersuchung des Konzeptes adaptiver Zustandsregelung anhand Parameteridentifikation},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_11.pdf}
}
2015 Seifert, R., Bahr, F. and Hofmann, W. Modellierung axialer Magnetlager aus Stahl- und SMC-Komponenten mit Wirbelstromeffekten Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: Die elektromagnetische Dynamik von axialen Magnetlagern ist im besonderen Maße von den eingesetzten Materialien abhängig. Axiale Flussverläufe machen eine Blechung von Stator und Rotor unwirksam und hohe induzierte Spannungen rufen im Magnetkreis wirbelstrombedingte Gegenfelder hervor. Zusätzliche kompensierende Magnetisierungsströme lassen den messbaren Strom der Steuerspule dem kraftbildenden Hauptfluss vorauseilen. Steigende Anforderungen an die Regeldynamik erfordern daher den Einsatz schwach elektrisch leitfähiger Kernmaterialien (Soft Magnetic Composites) oder eine Berücksichtigung der auftretenden Wirbelstromeffekte in der Regelstrecke unter Anwendung von Systemen gebrochenrationaler Ordnung. Beide Optionen werden in diesem Beitrag aus analytischer Sicht gegenübergestellt und ihre Anwendungsfälle diskutiert.
BibTeX:
@inproceedings{WMLT10_2,
  author = {R. Seifert and F. Bahr and W. Hofmann},
  title = {Modellierung axialer Magnetlager aus Stahl- und SMC-Komponenten mit Wirbelstromeffekten},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_2.pdf}
}
2015 Pilat, A.K. Study on radial active magnetic bearing for flexible shaft Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: This paper presents the results of selected analysis realised for the flexible shaft with a solid rotor and 8 pole heteropolar active magnetic bearing designed for a such configuration. The calculations were realised with the support of COMSOL Multiphysics software. The 3D models allowed to expand previous analysis with eigenfrequencies and electromagnetic force calculated for a complete bearing as well for deviated rotor (as simulated orientation for flexible mode).
BibTeX:
@inproceedings{WMLT10_3,
  author = {A. K. Pilat},
  title = {Study on radial active magnetic bearing for flexible shaft},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_3.pdf}
}
2015 Düsterhaupt, S. and Worlitz, F. Magnet- und Fanglagerprüfstand MFLP – Versuchsanlage zum Test von Magnet und Fanglagerungen unter extremen Bedingungen Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: Aktive Magnetlagerungen (AMB) stellen eine Schlüsseltechnologie in modernen Turbomaschinen dar. Der Einsatz von AMB in Turbomaschinen der Kraftwerkstechnik (Dampfturbinen, Kühlmittelpumpen und Verdichter) ist durch extreme Prozess- und Umgebungsbedingungen charakterisiert, wie hohe Temperaturen und korrosive Fluide/Gase. Insbesondere der Einsatz organischer Isolationsstoffe begrenzt derzeit den Einsatztemperaturbereich der elektromagnetischen Aktoren. Aktuell sind industrieübliche Isolationssysteme in Spulenwicklungen und Blechpaketen bis 180 °C dauerhaft temperaturstabil. Bekannte Isolationssysteme auf keramischer Basis erlauben Einsatztemperaturen bis zu 450 °C. Die Fertigung ist jedoch aufwendig und das Bauvolumen ist im Gegensatz zu konventionell isolierten Aktoren größer. Fortschritte in der Oberflächentechnik und in den Werkstoffwissenschaften ermöglichen die Entwicklung neuartiger Isolationssysteme. Diese eignen sich aufgrund ihrer Temperaturstabilität für den Einsatz in Hochtemperaturmagnetlagerungen (HTAMB). Beispielsweise erlaubt die Anwendung der PVDBeschichtungstechnologie (Physical Vapor Deposition) die Herstellung kostengünstiger Dünnschichten im einstelligen Mikrometerbereich. Weiterhin ist es ein erklärtes Ziel, Magnet- und Fanglagerungen (CB) in einer Baueinheit unterzubringen. Dies ermöglicht kompakte Maschinendesigns. Es ist geplant, diese Lagereinheiten nahe am oder direkt im Prozessraum unterzubringen. So müssen auch die Fanglagerungen ihre Funktionen unter extremen Umgebungsbedingungen zu erfüllen.
BibTeX:
@inproceedings{WMLT10_4,
  author = {S. Düsterhaupt and F. Worlitz},
  title = {Magnet- und Fanglagerprüfstand MFLP – Versuchsanlage zum Test von Magnet und Fanglagerungen unter extremen Bedingungen},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_4.pdf}
}
2015 Paditz, M., Nickel, A. and Hübner, N. Anwendungsbeispiele und Erfahrungen beim Einsatz magnetischer Lager Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: Seit mehr als 20 Jahren werden bei EAAT magnetische Lager und magnetgelagerte Antriebe, individuell angepasst an die Kundenanforderungen, entwickelt und gebaut. Zum Einsatz kamen diese Lager in zahlreichen Gebieten z. B. in der Kernforschung, der Medizintechnik, Textiltechnik und in Bearbeitungsmaschinen zum Fräsen und Bohren. Weiterhin finden Magnetlager Anwendung in der Prüftechnik z. B. zur Prüfung von Gleit- und Wälzlagern oder in der Materialprüftechnik. Auch für verschiedene Schwungrad- und Drallradanwendungen wurden bei EAAT schon Magnetlager entwickelt. In diesem Beitrag sollen einige Anwendungsbeispiele für magnetische Lager vorgestellt sowie auf Erkenntnisse und Erfahrungen beim Einsatz solcher Lager eingegangen werden.
BibTeX:
@inproceedings{WMLT10_5,
  author = {M. Paditz and A. Nickel and N. Hübner},
  title = {Anwendungsbeispiele und Erfahrungen beim Einsatz magnetischer Lager},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_5.pdf}
}
2015 Haje, D. Oelfreie Siemens Industriedampfturbine - Erste Betriebserfahrungen Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: Die erste ölfreie Siemens Industriedampfturbine wurde Anfang 2015 erfolgreich in Betrieb genommen und treibt seitdem eine Kesselspeisepumpe an. Dieser Beitrag berichtet über die ausgeführte Technik und erste Betriebserfahrungen.
BibTeX:
@inproceedings{WMLT10_6,
  author = {D. Haje},
  title = {Oelfreie Siemens Industriedampfturbine - Erste Betriebserfahrungen},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_6.pdf}
}
2015 Gouws, J., Rensburg, J.V. and Vanek, C. Backup-Bearing Lifetime Prediction using Quantified Delevitation Severity Indicators Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: In order to improve backup bearing reliability and safety, the applicability of using quantified delevitation severity indicators Dval, Vval (as described in [1]) and AVval for predicting backup bearing life is investigated. Degradation data is gathered using a small-scale experimental test bench to delevitate a rotor under specific initial conditions and simultaneously logging the Dval value for several repeated rotor delevitation events (RDEs). Three individual sets of backup bearing degradation data is shown indicating that delevitation severity indicators change as the bearing degrades. This change could enable condition monitoring of the backup bearings where the ultimate goal of this research is to induce repeatable backup bearing failures, and subsequently analyse the Dval, Vval and AVval data in order to predict future failures on a new set of backup bearings.
BibTeX:
@inproceedings{WMLT10_7,
  author = {J.M. Gouws and J.J. Van Rensburg and C. Vanek},
  title = {Backup-Bearing Lifetime Prediction using Quantified Delevitation Severity Indicators},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_7.pdf}
}
2015 Mitterhofer, H. Lagerloser Hochgeschwindigkeitsantrieb Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: Besonders bei Antrieben von generell kleiner Baugröße ist oft höchste Kompaktheit gefordert. Geht es dabei zusätzlich um ein magnetisch gelagertes System, so können lagerlose Motoren, die die magnetische Lagerung physisch mit dem elektrischen Motor vereinen, besonders interessant werden. Setzt die Anwendung außerdem auf einen scheibenförmigen Rotor, so kann aufgrund der magnetisch passiven Stabilisierung der axialen und Kippfreiheitsgrade (siehe Abbildung 2) ein Maximum an topologischer Kompaktheit realisiert werden.
BibTeX:
@inproceedings{WMLT10_8,
  author = {H. Mitterhofer},
  title = {Lagerloser Hochgeschwindigkeitsantrieb},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_8.pdf}
}
2015 Hoffmann, L. Wirbelstrommessketten speziell für Magnetlager Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: Die Anwendung von Magnetlagern sind vielfältig, so werden diese unter anderem im Werkzeugmaschinenbau eingesetzt. Anwendungsbeispiele sind dabei Fräsen, Schleifen, Bohren, Zentrifugen und Pumpen. Weiterhin eignen sich Magnetlager auch für Bearbeitungsspindeln für das Polieren von Oberflächen. Um eine sichere Regelung zu realisieren, werden hochauflösende und hochdynamische Messsysteme zur exakten Lagebestimmung eingesetzt. Hierfür werden oftmals Wirbelstrommesssysteme verwendet, da diese unempfindlich gegenüber Staub, Öl und weiteren Umgebungseinflüssen sind. Besondere Vorteile von Wirbelstromsensoren sind deren verhältnismäßig niedrige Preis und die Synchronisierbarkeit bei Wellendurchmessern unter 25 mm. Gegenwärtig werden in der EAAT u.a. Untersuchungen zur Herstellung eigener Wirbelstromsensoren durchgeführt. Hierzu werden neben den geeigneten Materialien für die Sensoren, deren notwendige Induktivität, der Einfluss verschiedener Sensorkopfdurchmesser etc. ermittelt. Grundlegende Schwerpunkte bilden geeignete Speisekabel und das Temperaturdriftverhalten, da Magnetlager auch für höhere Temperaturen einsetzbar sind. Die bevorzugten Baugrößen der Wirbelstromsensoren belaufen sich auf (6 und 8) mm Durchmesser. Das Fanglagerspiel und der kleinste Wellendurchmesser bestimmten dabei diese Baugrößen. Um Untersuchungen der Sensoren durchführen zu können, bedarf es einer geeigneten Auswerteelektronik. Die Anforderungen an diese Elektronik liegt in deren Universalität, d.h. es sollen nach Möglichkeit nicht nur eigens hergestellte Sensoren angeschlossen werden können, sondern ebenso auch Sensoren von Fremdherstellern. Dabei wird eine kostengünstige Auswerteelektronik angestrebt, welche zwischen Spannungs- und Stromcharakteristik umschaltbar ist. Bei Bedarf ist eine Linearisierung der Wirbelstrommesssignale möglich. Im Beitrag wird die Low-Cost Auswerteelektronik mit verschiedenen Linearisierungsvorschlägen der Sensorsignale als auch deren Universalität vorgestellt.
BibTeX:
@inproceedings{WMLT10_9,
  author = {L. Hoffmann},
  title = {Wirbelstrommessketten speziell für Magnetlager},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_9.pdf}
}
2014 Zhang, P., Wang, Z. and Xi, G. Novel Permanent-Magnet-Biased Axial Hybrid Magnetic Bearings Without a Thrust Disc Proceedings of ISMB14  
Abstract: The paper proposes a pair of novel permanent-magnet-biased axial hybrid magnetic bearings, which are assembled at ends of a compressor spindle. The outer diameter of rotor is minimized to reduce the wind loss, which is regarded as the main loss in a typical axial magnetic bearing for a compressor. The bias magnetic flux, provided by an axial polarized permanent magnet ring, diminishes the loss further. The paper firstly introduces the structure and the working principle of the new axial hybrid magnetic bearing system. The cooling holes are aimed to improving the cooling capability without degrading the load capacity. Then, the axial magnetic attraction forces of axial magnetic bearings in pairs, under the condition without the cooling holes, are calculated by 2-D Finite Element Method (FEM) and 3-D FEM respectively. Additionally, another 3-D model is set up to investigate the influence of the designed cooling holes on the axial force. The coupling of the magnetic force and the flux density limit of iron cores are analyzed. The numerical results indicate that the proposed structure of the axial magnetic bearing system is feasible.
BibTeX:
@inproceedings{ISMB14_1,
  author = {Pengfei Zhang and Zhiheng Wang and Guang Xi},
  title = {Novel Permanent-Magnet-Biased Axial Hybrid Magnetic Bearings Without a Thrust Disc},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_1.pdf}
}
2014 Garcia, J.D.G., Gomes, A.C.D.N. and Stephan, R.M. Performance Assessment of a Self-Bearing Motor: an Application of ISO 14839 Proceedings of ISMB14  
Abstract: Two different controllers have been applied for the stabilization of a self-bearing motor prototype existing at LASUP/UFRJ (Laboratory of Applied Superconductivity – Federal University of Rio de Janeiro): a PID controller and a LQR controller. This paper compares the performance of those controllers based on criteria described on the ISO 14839 standard, which establishes requirements for AMB (Active Magnetic Bearing) applied to turbo machinery.
BibTeX:
@inproceedings{ISMB14_10,
  author = {Jose Dalvio Ghirello Garcia and Afonso Celso Del Nero Gomes and Richard M. Stephan},
  title = {Performance Assessment of a Self-Bearing Motor: an Application of ISO 14839},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_10.pdf}
}
2014 Karban, P., Mach, F., Kus, P., Korous, L. and Dolezel, I. Code Agros2D and Possibilities of its Use for Modeling and Design of Magnetic Bearings Proceedings of ISMB14  
Abstract: A multi-platform software Agros2D is presented, whose purpose is to model complex 2D multiphysics problems in engineering practice. The code is intended for monolithic solving of systems of generally nonlinear and nonstationary partial differential equations describing particular physical fields. The numerical schemes implemented in the code are based on a fully adaptive higher-order finite element method. The paper discusses the unique features of the code and its internal structure. Its power is demonstrated on an example aimed at modeling of a passive axial magnetic bearing.
BibTeX:
@inproceedings{ISMB14_100,
  author = {Pavel Karban and Frantisek Mach and Pavel Kus and Lukas Korous and Ivo Dolezel},
  title = {Code Agros2D and Possibilities of its Use for Modeling and Design of Magnetic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_100.pdf}
}
2014 Imani-Nejad, M. and Trumper, D. Hysteresis Self-Bearing Motor Proceedings of ISMB14  
Abstract: This paper presents a hysteresis self-bearing motor along with its nonlinear analysis. In this work we introduced a new type of self-bearing motor with segmented stator. The major advantages of this stator are: easy and low cost manufacturing, higher filling factor and shorter magnetic path for the stator. We tested the self-bearing concept successfully with this new configuration. Hysteresis motors are suitable for high speed application since their rotor has neither permanent magnets nor any winding or mechanical features. We used FEA analysis to check the feasibility of proposed idea. Then we used Chua’s hysteresis model to simulate the nonlinear behavior of this system.
BibTeX:
@inproceedings{ISMB14_101,
  author = {Mohammad Imani-Nejad and David Trumper},
  title = {Hysteresis Self-Bearing Motor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_101.pdf}
}
2014 Murakami, M., Masuzawa, T., Onuma, H., Nishimura, T. and Kyo, S. The Thin Maglev Ventricular Assist Device with Radial Type Self-Bearing Motor Proceedings of ISMB14  
Abstract: A small, thin, maglev ventricular assist device, which can be implanted under the thorax muscle layer like a pacemaker, has been developed. A cascade pump, which has inlet and outlet ports in the same plane and a radial type self - bearing motor are adopted to reduce the axial thickness of the device. The radial self - bearing motor is using the passive stability to restrict the impeller movement in the axial direction and its inclination. We evaluated the fluid force acted on the levitated impeller by using the computational fluid dynamics analysis and restoring force and torque by using the magnetic field analysis. Also, an axial hydrodynamic bearing is developed to avoid the impeller contact on the casing when the levitated impeller received a large disturbance. Finally, a prototype pump is developed and evaluated its levitation and pump performance. The prototype pump was levitated and rotated up to a rotating speed of 2,600 rpm successfully. The target performance of a flow rate of 2 L /min against a head pressure of 100 mmHg is achieved with a rotating speed of 2,000 rpm. The maximum oscillation amplitude and the total power consumption with the target performance were 17 µm and 4.5 watts.
BibTeX:
@inproceedings{ISMB14_102,
  author = {Michiko Murakami and Toru Masuzawa and Hiroyuki Onuma and Takashi Nishimura and Syunei Kyo},
  title = {The Thin Maglev Ventricular Assist Device with Radial Type Self-Bearing Motor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_102.pdf}
}
2014 Asama, J., Fujii, Y., Fukuyo, M., Oiwa, T. and Chiba, A. Realization of Magnetic Suspension and Motor Operation with One Three-Phase Voltage Source Inverter Using a Zero-Phase Current Proceedings of ISMB14  
Abstract: This paper focuses on realization of both the single-axis active magnetic suspension and rotation of a three-phase permanent magnet motor using only one three-phase voltage source inverter. The suspension winding of the electromagnet for the single-axis magnetic suspension is connected between the neutral point of the Y-connected three-phase winding and the middle point of the voltage sources, and the resulting zero-phase current is utilized to control the suspension force. The control method of the zero-phase current is theoretically derived to avoid interference with the motor performance. Experimental apparatus was built and tested, which consists of an iron ball magnetic suspension system and a three-phase interior permanent magnet motor. The experimental results demonstrated stable magnetic suspension and motor rotation at 1200 rpm.
BibTeX:
@inproceedings{ISMB14_103,
  author = {Junichi Asama and Yusuke Fujii and Masato Fukuyo and Takaaki Oiwa and Akira Chiba},
  title = {Realization of Magnetic Suspension and Motor Operation with One Three-Phase Voltage Source Inverter Using a Zero-Phase Current},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_103.pdf}
}
2014 Ahn, H.J. and You, Y.H. An Eddy Current Damper for Reaction Force Compensation for a Linear Motor Motion Stage Proceedings of ISMB14  
Abstract: This paper presents an eddy current damper (ECD) for reaction force compensation for a linear motor motion stage. A reaction force compensation mechanism with a movable magnet track and an ECD (or conductor plate) is developed. Lumped model of the ECD is derived considering sinusoidal magnetic flux density distribution and effective width of the ECD. In addition, effects of both the location and width of the conductor plate are discussed. Multi-physical transient analysis of ECD is analyzed using commercial finite element software, which is compared with the lumped parameter analysis. Finally, the derived lumped model is validated with experiments.
BibTeX:
@inproceedings{ISMB14_104,
  author = {Hyeong Joon Ahn and Yo Han You},
  title = {An Eddy Current Damper for Reaction Force Compensation for a Linear Motor Motion Stage},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_104.pdf}
}
2014 Duesterhaupt, S., Neumann, H., Panescu, C., Rottenbach, T. and Worlitz, F. Test Field for Magnetic Bearing Applications Under Extreme Conditions Proceedings of ISMB14  
Abstract: Active magnetic bearings (AMB) are an essential key technology in modern power plant concepts. The application of AMBs in turbo machines (steam turbines, cooling pumps and compressors) is characterized by extreme process and environmental conditions like high temperatures, corrosive fluids and gases. Especially the use of organic materials limits the insulation level of electromagnetic actuators. Currently the allowed maximum continuous temperature of coils and laminated cores is 160C. Known solutions like ceramic insulation systems allow actuator temperatures up to 450C. But their production is complex and the specific actuator size increases compared to conventional insulated actuators. The development of new surface technologies and advances in material science allow new basic approaches for insulations and thereby for High Temperature Active Magnetic Bearings (HTAMBs). For instance the use of the physical vapor deposition technology (PVD) allows low cost coatings with thicknesses of only a few micrometers. Furthermore, the fusion of AMBs with catcher bearings (CB) to an integrated unit is advantageous for a compact machine design. It is one objective to place the bearing units close to the process section, if appropriate into the process section. So the CBs also have to fulfil their functions under extreme conditions.
BibTeX:
@inproceedings{ISMB14_105,
  author = {Stephan Duesterhaupt and Holger Neumann and Christian Panescu and Torsten Rottenbach and Frank Worlitz},
  title = {Test Field for Magnetic Bearing Applications Under Extreme Conditions},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_105.pdf}
}
2014 Tripodi, E., Musolino, A., Rizzo, R. and Casini, D. Stability Analysis of a New Passive PMs Bearing Proceedings of ISMB14  
Abstract: In this paper a new Permanent Magnets (PMs) bearing is presented. The device is composed of a rotor capable to levitate at a short distance from a dedicated stator. The magnetic suspension is achieved by proper configurations of PMs arranged on both the stator and the rotor. The device is characterized by intrinsic instability and passive stabilization is attempted exploiting eddy currents on a conducting sheet surrounding the stator magnets. The system has been simulated by means of a dedicated numerical tool capable to take into account the effects of the magneto-mechanical coupling. In particular, the coupled problem has been integrated by means of a prediction-correction nested scheme. The simulation activity has produced some interesting results, that are here extensively discussed. More specifically, it has been shown that the stability with respect to the center of mass translation can be passively obtained, if the rotations are actively prevented. An idea of an active stabilizing system for the rotations, exploiting the results of the simulation is finally briefly described.
BibTeX:
@inproceedings{ISMB14_106,
  author = {Ernesto Tripodi and Antonino Musolino and Rocco Rizzo and Dante Casini},
  title = {Stability Analysis of a New Passive PMs Bearing},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_106.pdf}
}
2014 Rudolph, J. and Werner, R. Effect of Eddy Currents on the Stray Flux Based Measurement System for Magnetic Bearing Proceedings of ISMB14  
Abstract: This paper concerns the behaviour and special characteristics of an alternative measurement system for magnetic bearing based on stray flux which depends on the rotor position. The impact of eddy currents on the dynamic properties will be analysed and methods for compensation will be presented. Furthermore the effect of electromagnetic disturbance will be a matter and how it can be reduced by special sensor design.
BibTeX:
@inproceedings{ISMB14_107,
  author = {Johannes Rudolph and Ralf Werner},
  title = {Effect of Eddy Currents on the Stray Flux Based Measurement System for Magnetic Bearing},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_107.pdf}
}
2014 Li, L., Kästner, W. and Worlitz, F. Adaptive Kalman Filter for Active Magnetic Bearings Using softcomputing Proceedings of ISMB14  
Abstract: Magnetic bearings can not only solve the bearing wear and life problems but also reduce the loss and noise of bearing. However, the strong disturbance and noise from the system affects the control behavior. Based on the Kalman filter the influence of noise will be reduced. But the strong nonlinear and uncertainty of parameter of the magnetic bearings make it difficult to establish the estimation / prediction equation in Kalman filter. This paper presents a design method of system estimation / prediction for Kalman filter with using soft computing. Firstly, linear local model for axial magnetic bearing overall system will be deduced. Then a few system parameters, which is relative with nonlinear and uncertainty, will be obtained by a intelligence function, which uses soft computing algorithm as system identification. Finally, the identified system parameters will be used in state equation in Kalman filter. It aims at better filter performance and state estimation than the conventional linear Kalman filter.
BibTeX:
@inproceedings{ISMB14_108,
  author = {Li Li and Wolfgang Kästner and Frank Worlitz},
  title = {Adaptive Kalman Filter for Active Magnetic Bearings Using softcomputing},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_108.pdf}
}
2014 Fohler, A. and Zulehner, W. Nitsche-Type Mortaring for Simulation of Electrical Machines Proceedings of ISMB14  
Abstract: We will present a finite element program implementing the idea of Nitsche-type mortaring in the framework of simulating electrical machines. Using this method it is possible to split the domain into subdomains only connected via a function on the interface. From this approach we gain the advantage that adjacent meshes (e.g. rotor and air gap) do not have to fit together nodewise. The mortaring will be used on the interface between rotor and air gap as well as on the symmetry edges of the motor, since only a part of the machine is considered in the simulation due to motor symmetry.
BibTeX:
@inproceedings{ISMB14_109,
  author = {Armin Fohler and Walter Zulehner},
  title = {Nitsche-Type Mortaring for Simulation of Electrical Machines},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_109.pdf}
}
2014 Sun, Z., Zhao, J. and Shi, Z. Identification of Magnetic Bearing System Using a Novel Subspace Identification Method Proceedings of ISMB14  
Abstract: Active magnetic bearings (AMBs) are widely applied to support high-speed rotating machineries, especially in special environment. Identification is a useful method to obtain the mathematical model of an AMB system. Frequency domain subspace identification method (FDSIM) is an attractive identification technique. However, in practice one usually expects that the identified model possesses some properties, for example stability. FDSIM cannot ensure these expected properties. This paper firstly proposes a novel subspace identification method, FDSIM-lamda. This method can guarantee that the resultant model possesses predefined poles. Moreover, an optimization procedure is introduced to obtain the optimal poles based on FDSIM-lamda, the initial estimation of system poles and constraints on the system poles. The proposed method is then applied to identify an AMB system and validated by the experiments on a real AMB system.
BibTeX:
@inproceedings{ISMB14_11,
  author = {Zhe Sun and Jingjing Zhao and Zhengang Shi},
  title = {Identification of Magnetic Bearing System Using a Novel Subspace Identification Method},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_11.pdf}
}
2014 Masuzawa, T. Magnetically Suspended Motor System for Artificial Hearts and Blood Pumps Proceedings of ISMB14  
Abstract: Magnetic levitation technology, for magnetic bearings and magnetically suspended motors, is a cutting edge technology to produce artificial hearts and higher performance blood pumps. A wider blood gap and eliminating the contacting parts in the device based on the maglev technology provide better blood compatibility and higher durability of the device. Novel inventions about the maglev mechanism are required to overcome the size and power limitation of artificial hearts. Specialization of the maglev system is also necessary due to different requirements with the spreading application of artificial hearts. The current research topics of the maglev system for artificial hearts and blood pumps will be presented in the mini-symposium.
BibTeX:
@inproceedings{ISMB14_110,
  author = {Toru Masuzawa},
  title = {Magnetically Suspended Motor System for Artificial Hearts and Blood Pumps},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_110.pdf}
}
2014 Marth, E., Jungmayr, G. and Amrhein, W. Realization of a Multi-Pole Permanent Magnetic Bearing with Rotating Magnetization Proceedings of ISMB14  
Abstract: The optimization of stiffness of a permanent magnetic single ring bearing is presented in this paper. This is achieved by only changing the magnetization pattern. More precisely, a homogeneous magnetization is replaced by a rotating magnetization with two magnetic poles, leading to a 3.7-fold improvement in stiffness. Usually, such a rotating magnetization is realized by stacking several homogeneously magnetized rings with different magnetization direction, which is referred to as Halbach stacking. Our approach was to realize a continuously rotating magnetization pattern in one ring. In order to achieve the maximum possible stiffness for the given bearing dimensions, the optimization of the magnetization process is crucial and also presented in the paper.
BibTeX:
@inproceedings{ISMB14_111,
  author = {Edmund Marth and Gerald Jungmayr and Wolfgang Amrhein},
  title = {Realization of a Multi-Pole Permanent Magnetic Bearing with Rotating Magnetization},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_111.pdf}
}
2014 Kurita, N., Timms, D., Greatrex, N., Kleinheyer, M. and Masuzawa, T. Optimization Design of Magnetically Suspended System for the BiVACOR Total Artificial Heart Proceedings of ISMB14  
Abstract: The BiVACORdevice is a third generation rotary total artificial heart under development to treat end stage cardiovascular disease. Non-contact suspension and rotation of the impeller of the blood pump was achieved by a combination of a permanent magnet hybrid type magnetic bearing and an axial flux brush-less DC motor. Moreover, according to a series of animal trials, functionality of the proposed magnetic system in the total artificial heart application was clarified.
BibTeX:
@inproceedings{ISMB14_112,
  author = {Nobuyuki Kurita and Daniel Timms and Nicholas Greatrex and Matthias Kleinheyer and Toru Masuzawa},
  title = {Optimization Design of Magnetically Suspended System for the BiVACOR Total Artificial Heart},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_112.pdf}
}
2014 Schneider, M., Schaede, H. and Rinderknecht, S. Multicriteria Design Process for Outer-Rotor Kinetic Energy Storage Systems Proceedings of ISMB14  
Abstract: Due to the global energy transition, energy storage capacities are necessary. Kinetic energy storage systems can be used to provide valuable grid services but have to be redesigned to fulfill this task. A structured process is necessary in order to cope with the complexity of those systems and to maximize performance and profitability. This multicriteria design process is described in detail for an outer-rotor kinetic energy storage system. The approach is based on a detailed system model consisting of the several sub-models. It incorporates the design of the drive system, the magnetic bearing system, as well as the composite rotor. This approach enables the use of optimization algorithms in order to find systems matching the application specific objectives such as minimal operational losses or a maximal energy density. The multicriteria design process is then applied to an exemplary application.
BibTeX:
@inproceedings{ISMB14_113,
  author = {Maximilian Schneider and Hendrik Schaede and Stephan Rinderknecht},
  title = {Multicriteria Design Process for Outer-Rotor Kinetic Energy Storage Systems},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_113.pdf}
}
2014 Mitterhofer, H. and Rakov, M. On the Direct Use of Electromagnetic Field Information for Rotor Position Control Proceedings of ISMB14  
Abstract: This article describes a simple principle for obtaining information about the radial rotor position and later on shows how this information can be used to stabilize the rotor deflection in a magnetically levitated system. It is important to notice that the considered demonstration system was designed in a way the discussed effects are clearly noticeable. It is not meant to be a design proposal for an actual motor.
BibTeX:
@inproceedings{ISMB14_114,
  author = {Hubert Mitterhofer and Mikhail Rakov},
  title = {On the Direct Use of Electromagnetic Field Information for Rotor Position Control},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_114.pdf}
}
2014 Hinterdorfer, T., Schulz, A., Sima, H., Hartl, S. and Wassermann, J. Compensation of Unbalance Forces of a Switched Reluctance Machine with Combined Current and Fluxlinkage Control Proceedings of ISMB14  
Abstract: The presented work handles the compensation of unbalance forces for a 6/4-Switched Reluctance Machine (SRM), which generate significant radial magnetic forces in an eccentric motor shaft position. When the rotor is operating e.g. in its principal axis of inertia, these forces must be compensated by the bearings. This is of major interest for long term storage Flyweels where bearing efficiency is a key factor for the overall system performance. Due to the back electromotive force (BEMF) in high speed operation, precise current control is a major challenge. Hence a combination of current and fluxlinkage control is used to minimize the generated radial forces. It can be used for low and high speed applications. For the observation of fluxlinkage two different methods are described. The functionallity is shown by means of simulations and measurement.
BibTeX:
@inproceedings{ISMB14_115,
  author = {Thomas Hinterdorfer and Alexander Schulz and Harald Sima and Stefan Hartl and Johann Wassermann},
  title = {Compensation of Unbalance Forces of a Switched Reluctance Machine with Combined Current and Fluxlinkage Control},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_115.pdf}
}
2014 Hinterdorfer, T., Schulz, A., Sima, H., Hartl, S. and Wassermann, J. Topology Optimization of a Flywheel Energy Storage Rotor Using a Genetic Algorithm Proceedings of ISMB14  
Abstract: This paper deals with topology optimization of the rotor of a flywheel energy storage system (FESS). For isotropic materials the constant stress disc (CSD) is the best choice to maximize energy density. Modern FESS are manufactured of fiber reinforced plastics (FRP), due to their high specific strength. Because of the transverse isotropic material description the optimal rotor topology changes. A genetic algorithm (GA) for nonlinear integer problems will be used to find the best rotor structure which can be manufactured within one filament winding process.
BibTeX:
@inproceedings{ISMB14_116,
  author = {Thomas Hinterdorfer and Alexander Schulz and Harald Sima and Stefan Hartl and Johann Wassermann},
  title = {Topology Optimization of a Flywheel Energy Storage Rotor Using a Genetic Algorithm},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_116.pdf}
}
2014 van Rensburg, J.J., Vanek, C. and Worlitz, F. Backup Bearing Modelling for Turbo Machines with High Axial and Radial Loads Proceedings of ISMB14  
Abstract: The use of active magnetic bearings (AMBs) in turbo machines is an active research topic and the implementation in industrial applications is becoming commonplace. This is especially true when investigating the backup bearings (BBs) for high speed rotors with high axial and radial loads. In AMB supported turbo machines there usually are high axial process forces present, and should the axial AMB (AAMB) fail, these forces need to be supported by the axial backup bearings (ABBs). In order to design appropriate BBs the movement of the rotor and the associated forces produced during a rotor delevitation event (RDE) is of critical importance. These forces should be determined using a rotor delevitation model that includes the forces on all the backup bearings and the effect that these forces have on the rotor stability. This paper presents a short overview of various types of ABBs in the literature and the associated models for these BBs. The second part of the paper presents a model for a novel BB currently under construction at the IPM, and how this model is integrated into the rotor delevitation model BBSim [1]. The third part of the paper presents some results obtained using the proposed ABB model. The results investigate the effect that the radial distance where contact occurs and the axial force present on the rotor has on the RDE severity based on the Vval values.
BibTeX:
@inproceedings{ISMB14_117,
  author = {Jan Janse van Rensburg and Christian Vanek and Frank Worlitz},
  title = {Backup Bearing Modelling for Turbo Machines with High Axial and Radial Loads},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_117.pdf}
}
2014 Siebke, P. and Golbach, H. A Novel Rolling Element Back-Up Bearing for a 9t Rotor Application Proceedings of ISMB14  
Abstract: The paper outlines the development of a novel backup bearing unit which complements Siemens’ new magnetic bearings for an electric motor with a 9 t rotor. The back-up bearing utilizes rolling bearing elements. Principles for the rotor supported by the back-up bearings are derived and used to design the novel, so-called “Smiley” design. Dynamic simulations are presented predicting that the system fulfils the requirements. This is proven by comparison with experimental data.
BibTeX:
@inproceedings{ISMB14_118,
  author = {Peter Siebke and Hermann Golbach},
  title = {A Novel Rolling Element Back-Up Bearing for a 9t Rotor Application},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_118.pdf}
}
2014 Jungmayr, G., Berroth, H.-J., Panholzer, M., Marth, E., Amrhein, W., Jeske, F. and Reisinger, M. Design of a Highly Reliable Fan with Magnetic Bearings Proceedings of ISMB14  
Abstract: Long term analysis at ebm-papst St. Georgen GmbH & Co. KG showed that bearing failures are responsible for 90% of compact fan breakdowns. A magnetically levitated impeller has no contact with the stator and therefore the life expectancy can be essentially increased. This paper presents the design of a magnetically levitated fan. To meet the low-cost requirement, passive magnetic bearings (PMBs) are used to stabilize the radial and tilt deflections of the rotor. By applying an optimized viscoelastic support to the stator, sufficient damping is introduced to the passively stabilized degrees of freedom. The optimization of the stiffness and damping is discussed and the design of the key components, namely the PMB, the active magnetic bearing (AMB) and the passive damping device, is described. Finally the built prototype and measurements are presented.
BibTeX:
@inproceedings{ISMB14_119,
  author = {Gerald Jungmayr and Hans-Jörg Berroth and Martin Panholzer and Edmund Marth and Wolfgang Amrhein and Frank Jeske and Martin Reisinger},
  title = {Design of a Highly Reliable Fan with Magnetic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_119.pdf}
}
2014 Tachibana, K. and Oka, K. Study on Bearingless Motor with Rectified Circuit Coil Proceedings of ISMB14  
Abstract: This paper represents the research finding of levitation and rotation control on bearingless motor with rectified circuit coil. Rectified circuit coil is functioned as transmitting and receiving coil of wireless electric power transmission, and supplies direct current to rotor coils. Rotor coils are used as rotor magnets not using permanent magnets. Even if magnetic force of magnet is strong, normal force will not be generated if magnets are horizontally configured on straight line. So as to generate vertical axial force, the tip form of rotor and stator is made to incline and levitation force (vertical axial force) is acquired using this inclination.
BibTeX:
@inproceedings{ISMB14_12,
  author = {Kunihiko Tachibana and Koichi Oka},
  title = {Study on Bearingless Motor with Rectified Circuit Coil},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_12.pdf}
}
2014 Schmied, J. Rotordynamic Simulations with MADYN 2000 Proceedings of ISMB14  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB14_120,
  author = {Joachim Schmied},
  title = {Rotordynamic Simulations with MADYN 2000},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_120.pdf}
}
2014 Bauer, W., Freudenthaler, P. and Amrhein, W. Experimental Characterization of a Bearingless Rotating Field Axial-Force/Torque Motor Proceedings of ISMB14  
Abstract: The Bearingless Axial-Force/Torque Motor is an air-core coil motor, that can generate axial forces and drive torques concurrently using a common stator winding system. The radial suspension and the tilting stabilization of the bearingless drive is realized by passive repulsive permanent magnetic ring bearings. The end-windings of the concentric, non-overlapping stator coils create axial directed levitation forces, provided that a non-vanishing common-mode current component is present. In contrast to the existing alternating field motor topology, the proposed redesign features a rotating field motor structure for constant, rotor-angle independent drive torque generation. The current investigation concentrates on the verification of the drive parameters via simple and robust measurements. A presentation of the functional prototype concludes the article.
BibTeX:
@inproceedings{ISMB14_121,
  author = {Walter Bauer and Paul Freudenthaler and Wolfgang Amrhein},
  title = {Experimental Characterization of a Bearingless Rotating Field Axial-Force/Torque Motor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_121.pdf}
}
2014 Silber, S., Koppelstätter, W., Weidenholzer, G. and Bramerdorfer, G. MagOpt - Optimization Tool for Mechatronic Components Proceedings of ISMB14  
Abstract: MagOpt is a modular software tool for the simulation and optimization of mechatronic components. It features a flexible structure for the storage of complex data and an open and modular interface to existing third party programs like CAD systems, finite element programs and other simulation software. Parametric design optimization can be carried out with various different optimization strategies like gradient-based methods or multi-objective evolutionary or genetic algorithms.
BibTeX:
@inproceedings{ISMB14_122,
  author = {Siegfried Silber and Werner Koppelstätter and Günther Weidenholzer and Gerd Bramerdorfer},
  title = {MagOpt - Optimization Tool for Mechatronic Components},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_122.pdf}
}
2014 Grund, C. and Haje, D. Qualification of Magnetic Bearings for Industrial Turbines Proceedings of ISMB14  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB14_123,
  author = {Christoph Grund and Detlef Haje},
  title = {Qualification of Magnetic Bearings for Industrial Turbines},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_123.pdf}
}
2014 Gruber, W., Bauer, W. and Radman, K. Comparison of Homopolar and Heteropolar Bearingless Reluctance Slice Motor Prototypes Proceedings of ISMB14  
Abstract: This paper focuses on the operational behavior of two bearingless reluctance slice motor prototypes. After a brief introduction of the two systems, experiences, obtained from both novel bearingless drives, are presented. On this basis, communalities and differences, in various areas, e. g. construction, geometric constraints, winding systems, force to torque ratio, power electronic utilization and efficiency, will be outlined. This will help to point out the applicability of the reluctance slice motor concepts for industrial utilization.
BibTeX:
@inproceedings{ISMB14_124,
  author = {Wolfgang Gruber and Walter Bauer and Karlo Radman},
  title = {Comparison of Homopolar and Heteropolar Bearingless Reluctance Slice Motor Prototypes},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_124.pdf}
}
2014 Radman, K., Bulic, N. and Gruber, W. Loss Analysis of a Bearingless Flux-Switching Slice Motor Proceedings of ISMB14  
Abstract: The bearingless flux-switching slice motor is a recently developed motor concept combining the magnetic rotor suspension of a bearingless slice drive and the topology of a flux-switching drive. In comparison to state of the art bearingless slice motors this concept introduces a magnet free rotor and relatively high torque generation. This offers advantages in industrial and medical applications which require regular rotor replacements and high temperature working conditions. This work will describe the working principles, prototype design, implemented control theory and measurement to determine the losses and evaluate the efficiency.
BibTeX:
@inproceedings{ISMB14_125,
  author = {Karlo Radman and Neven Bulic and Wolfgang Gruber},
  title = {Loss Analysis of a Bearingless Flux-Switching Slice Motor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_125.pdf}
}
2014 Schultz, L., de Haas, O., Berger, D., Kühn, L., Berger, A. and Espenhahn, T. Basics of Superconducting Levitation and its Use in the Transport System SupraTrans II Proceedings of ISMB14  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB14_126,
  author = {Ludwig Schultz and Oliver de Haas and Dietmar Berger and Lars Kühn and Anne Berger and Tilo Espenhahn},
  title = {Basics of Superconducting Levitation and its Use in the Transport System SupraTrans II},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_126.pdf}
}
2014 Weickhmann, M., Katter, M. and Schleede, B. Nd-Fe-B Permanent Magnets for Passive and Hybrid Magnetic Bearings with Extended Application Temperature Range Proceedings of ISMB14  
Abstract: Passive magnetic bearings or hybrid passive magnetic bearings are commonly built up with Sm-Co or with Nd-Fe-B magnets. One of the most important item of those magnets is it’s homogeneity in flux density distribution and the precise angularity. A miss-match would cause an undesired displacement. It may therefore be very important to measure these homogeneity’s and angular deviation very precisely. Some application call for a higher temperature, thus a need of higher remanence Br is inevitable and in some cases the temperature coefficient Tk of remanence Br is also of importance. This may be achieved by applying the Grain Boundary Diffusion GBD. In the following paper we will give an overview of the current development to ensure this future demand. A variation of parameter studies will give an overview of the main influencing factors which act on the bearing forces and stiffness.
BibTeX:
@inproceedings{ISMB14_127,
  author = {Michael Weickhmann and Matthias Katter and Bernd Schleede},
  title = {Nd-Fe-B Permanent Magnets for Passive and Hybrid Magnetic Bearings with Extended Application Temperature Range},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_127.pdf}
}
2014 Poltschak, F. Active Reduction of Bearing Forces of Short Stroke Linear Actuators Proceedings of ISMB14  
Abstract: Linear magnetic actuators are used in industry for a wide area of applications. In order to reach high values for the axial thrust force, the mover commonly features a permanent magnet excitation. Thus, in combination with a slotted stator layout, these actuators exhibit a high destabilizing stiffness in the direction perpendicular to the direction of motion which has to be compensated by the linear bearings. This paper introduces a linear short stroke actuator with an integrated active bearing force compensation to minimize the forces acting on the mechanical bearings. The potential and limits of a bearing force compensation is analyzed based on a short stroke linear actuators with an E-shaped stator layout. It is outlined how far bearing forces can be compensated even for simple actuator layouts. Especially for linear drives oscillating with a high speed this compensation can significantly reduce wear and thus improve lifetime and efficiency as well as reduce the size of the mechanical bearings.
BibTeX:
@inproceedings{ISMB14_128,
  author = {Florian Poltschak},
  title = {Active Reduction of Bearing Forces of Short Stroke Linear Actuators},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_128.pdf}
}
2014 de Haas, O. and Kuehn, L. Superconducting Magnetic Bearings for Industrial Applications Proceedings of ISMB14  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB14_129,
  author = {Oliver de Haas and Lars Kuehn},
  title = {Superconducting Magnetic Bearings for Industrial Applications},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_129.pdf}
}
2014 Fohr, F., Volbers, N. and Gerster, J. High Strength Iron-Cobalt Materials for Magnetic Bearings Proceedings of ISMB14  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB14_13,
  author = {Frederik Fohr and Niklas Volbers and Joachim Gerster},
  title = {High Strength Iron-Cobalt Materials for Magnetic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_13.pdf}
}
2014 Lembke, T. Review of Electrodynamic Bearings Proceedings of ISMB14  
Abstract: When Earnshaw stated his theorem in 1839, it did not seem possible to levitate objects in static magnetic fields. 100 years later Braunbeck 1939 was able to show mathematically that levitation is actually possible in unvarying magnetic fields for diamagnetic materials. Today levitating toys based on weakly diamagnetic graphite and permanent magnets are available on the market. Some other materials like superconductors or moving conductors have properties that to a much higher extent resemble those of diamagnets, and these may also levitate in a static magnetic field. Levitating experimental full scale trains based on both of these effects exist today. In this paper the most important technical achievements regarding electrodynamic levitation will be reviewed, dating from 1922 and on, with particular focus on rotating bearings and demonstrated levitating prototypes.
BibTeX:
@inproceedings{ISMB14_130,
  author = {Torbjörn Lembke},
  title = {Review of Electrodynamic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_130.pdf}
}
2014 Allaire, P., Jiang, W., Kailasan, A. and Dimond, T. Magnetic Bearing System for Left Ventricular Assist Artificial Heart Pump - Combined Active and Passive Configuration Proceedings of ISMB14  
Abstract: Magnetic bearings continue to contribute to the development of ventricular assist artificial heart pumps. This paper describes the magnetic suspension for a unique prototype axial flow pump designed for approximately 6 l/min at 100 mm Hg performance with an operating speed of approximately 7,000 rpm. The integrated magnetic suspension design provides a direct non-contact blood flow path through the pump with no obstructions which might create low flow areas and thrombosis (blood clots). The magnetic suspension is a combination of permanent magnets (PMs) and active magnetic bearings (AMBs). There are two radial AMBs which support the four degrees of freedom at the ends of the axial pump impeller and an axial PM thrust bearing. The axial PM bearing supports the direction of the largest fluid force on the impeller. A major objectives of artificial hearts is to have extremely low power consumption. Thus the integrated PM and AMB suspension system has an operating magnetic suspension power of approximately 2 watts. The design, numerical modeling, and testing of the magnetic suspension system to support the fluid loads and the g loads is described in the paper.
BibTeX:
@inproceedings{ISMB14_131,
  author = {Paul Allaire and Wei Jiang and Arunvel Kailasan and Tim Dimond},
  title = {Magnetic Bearing System for Left Ventricular Assist Artificial Heart Pump - Combined Active and Passive Configuration},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_131.pdf}
}
2014 Jiang, K. and Zhu, C. Identification of Stiffness and Damping via SPHS Excitation and Multi-DOF Active Magnetic Bearing-Rotor Model Proceedings of ISMB14  
Abstract: The equivalent stiffness and the equivalent damping are the important and commonly used parameters for representing the support characteristic of the Active Magnetic Bearing(AMB). A method for measuring the equivalent stiffness and the equivalent damping is proposed with parameter identification via the multi-frequency excitation. The parameter identification is based on the multi-degree of freedom(DOF) rotor model, not the single DOF model, which can not be suitably applied to the multi-DOF AMB-rotor system. Additionally, the Schroeder Phased Harmonic Sequences(SPHS) are applied to generate the signal for the multi-frequency excitation. SPHS can achieve the lowest peak value by means of appropriate selection for the relative phasing of each frequency component, so that the possibility of the rotor vibration exceeding clearances of AMB and the magnetic force reaching saturation is minimized. Finally, the experiments indicate that the proposed method can efficiently reduce the peak value for the superimposed multi-frequency excitation and correctly identify the equivalent stiffness and equivalent damping of the AMB-rotor system. Keywords: active magnetic bearing, multi-frequency excitation, Schroeder phased harmonic sequences, equivalent stiffness, equivalent damping
BibTeX:
@inproceedings{ISMB14_132,
  author = {KeJian Jiang and ChangSheng Zhu},
  title = {Identification of Stiffness and Damping via SPHS Excitation and Multi-DOF Active Magnetic Bearing-Rotor Model},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_132.pdf}
}
2014 Jeon, J.-W., Lee, C.-L., Oh, H.-S. and Kim, J.-M. Novel Cylindrical Magnetic Levitation Stage with High Precision Motion Proceedings of ISMB14  
Abstract: This paper proposed novel cylindrical magnetic levitation stage. This stage can move the cylinder to rotations and translations as well as levitations with high precision in vacuum. This advantage is useful to make a nano patterning on the surface of cylindrical specimen by using electron beam lithography. In this paper, a conceptual design and a detailed design of the novel cylindrical magnetic levitation stage are shown. Firstly, mathematical modeling and simulation results are shown and then experimental results are compared after manufactured.
BibTeX:
@inproceedings{ISMB14_14,
  author = {Jeong-Woo Jeon and Chang-Lin Lee and Hyeon-Seok Oh and Jong-Moon Kim},
  title = {Novel Cylindrical Magnetic Levitation Stage with High Precision Motion},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_14.pdf}
}
2014 Rao, J., Hijikata, W. and Shinshi, T. A Permanent Magnet Free Bearingless Motor for Disposable Centrifugal Blood Pump Proceedings of ISMB14  
Abstract: The disadvantages of disposable centrifugal blood pumps (DCBPs) are the high cost of the disposable pump head due to the use of rare earth magnets and the complex-shaped secondary flow channel due to the space allocated for the magnetic coupling. In order to overcome these problems a permanent magnet free bearingless motor for DCBPs with a smooth secondary flow channel has been developed. The radial position and rotational speed of the rotor are actively controlled, and the axial position and tilt angle of the rotor are passively stabilized by a magnetic reluctance force. Results of magnetic field FEM analysis showed that the proposed bearingless motor has an axial stiffness of 3.50 N/mm and a tilt stiffness of 0.87 Nm/rad. In an experiment, the power consumption of the prototype was less than 30 W without load at a rotational speed of 3000 rpm.
BibTeX:
@inproceedings{ISMB14_15,
  author = {Jun Rao and Wataru Hijikata and Tadahiko Shinshi},
  title = {A Permanent Magnet Free Bearingless Motor for Disposable Centrifugal Blood Pump},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_15.pdf}
}
2014 Mizuno, T., Takahashi, K., Ishino, Y. and Takasaki, M. Proposal of AC Magnetic Suspension Using Magnetic Resonant Coupling Proceedings of ISMB14  
Abstract: A novel AC magnetic suspension using magnetic resonant coupling is proposed and studied both theoretically and experimentally. The conventional AC magnetic suspension with energy transfer function has a problem that energy transfer efficiency is very low because it has a gap. In contrast, even if it has a gap, the energy transfer method using magnetic resonant coupling has high efficiency. In this paper, this method is combined with AC magnetic suspension. An experimental apparatus is fabricated for basic study. The floator was successfully suspended without control, and the self-stabilization characteristic is confirmed.
BibTeX:
@inproceedings{ISMB14_16,
  author = {Takeshi Mizuno and Kei Takahashi and Yuji Ishino and Masaya Takasaki},
  title = {Proposal of AC Magnetic Suspension Using Magnetic Resonant Coupling},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_16.pdf}
}
2014 Schaeffel, C., Katzschmann, M., Mohr, H.-U., Gloess, R., Rudolf, C., Mock, C. and Walenda, C. 6D Planar Magnetic Levitation System - Mag6D Proceedings of ISMB14  
Abstract: The paper describes the structure, the performance and a set of model based design steps of a novel 6 DOF planar magnetic drive system with nanometer positioning accuracy. The movable platform of the system is free of any wiring connection and the upper surface is freely accessible.
BibTeX:
@inproceedings{ISMB14_17,
  author = {Christoph Schaeffel and Michael Katzschmann and Hans-Ulrich Mohr and Rainer Gloess and Christian Rudolf and Christopher Mock and Carolin Walenda},
  title = {6D Planar Magnetic Levitation System - Mag6D},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_17.pdf}
}
2014 Hofer, M., Hutterer, M., Nenning, T. and Schrödl, M. Improved Sensorless Control of a Modular Three Phase Radial Active Magnetic Bearing Proceedings of ISMB14  
Abstract: This paper discusses new results and improvements on the sensorless control of a permanent magnet biased three phase radial active magnetic bearing (AMB), which are also known as hybrid magnetic bearings (HMB). Self-sensing methods offer cost potentials because of a more simple bearing system architecture, but show lower performance in accuracy and bandwidth compared to external position sensors. Thus, making selfsensing technologies competitive to systems with position sensors is a broad field of research and as well a goal of this paper. The proposed sensorless method is based on inductance measurement by voltage pulse injection. Applying an oversampling strategy for current slope measurement reduces the noise of the sensorless obtained rotor position significantly. Timing limitations and operational bandwidth can be improved by utilizing alternative voltage pulse sequences. Further, variations of the permanent magnet bias flux of the HMB prototype are investigated to show the influences on the sensorless rotor position detection method and limitations for applications.
BibTeX:
@inproceedings{ISMB14_18,
  author = {Matthias Hofer and Markus Hutterer and Thomas Nenning and Manfred Schrödl},
  title = {Improved Sensorless Control of a Modular Three Phase Radial Active Magnetic Bearing},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_18.pdf}
}
2014 Dumont, C., Kluyskens, V. and Dehez, B. Impact of the Yoke Material on the Performance of Wounded Electrodynamic Bearings Proceedings of ISMB14  
Abstract: This paper concerns null-flux, centering electrodynamic bearings with an internal rotor made of permanent magnets creating a multipole radial magnetic field and with an external airgap wounded conductor attached to a yoke. The inclusion of a ferromagnetic yoke in front of the permanent magnets has the two following effects. On the one hand, it increases the magnetic flux density in the airgap and the magnitude of the centering Lorentz forces between the rotor and the stator of the device. This is positive since the stiffness associated with the centering force of the bearing increases too. On the other hand, it also induces a negative stiffness due to the reluctant force between the yoke and the magnets usually referred to as the unbalanced magnetic force. The goal of this paper is to investigate about the gain in stiffness and performance associated with the presence of a ferromagnetic yoke in multipole electrodynamic bearings. To this purpose, a method is exposed to evaluate the stiffness and stability of the bearing objectively using a root-loci plot. The results are based on a 2-D analytical model of electrodynamic bearings which is briefly presented in the paper. It is shown that in some cases, the magnetic permeability of the yoke has a very low impact on the bearing performance.
BibTeX:
@inproceedings{ISMB14_19,
  author = {Corentin Dumont and Virginie Kluyskens and Bruno Dehez},
  title = {Impact of the Yoke Material on the Performance of Wounded Electrodynamic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_19.pdf}
}
2014 Genta, G. Kinetic Energy Storage: an Ideal Application for Magnetic Bearings Proceedings of ISMB14  
Abstract: Kinetic energy storage systems have a long history, but in the last half a century many studies and projects aimed to make this form of energy storage competitive with other systems were developed. One of the main problems related to flywheel energy storage is linked to the energy dissipations due to aerodynamic and bearing drag: Magnetic bearings, also due to their ability of working in vacuum, are thus intrinsically required for these applications.
BibTeX:
@inproceedings{ISMB14_2,
  author = {Giancarlo Genta},
  title = {Kinetic Energy Storage: an Ideal Application for Magnetic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_2.pdf}
}
2014 Ding, Q., Wu, G., Deng, Z. and Wang, X. Influence of Fault-Tolerant Stator Structure on Performance of Permanent Magnet Bearingless Slice Machines Proceedings of ISMB14  
Abstract: Fault-tolerant capability is a vital requirement for bearingless slice machine which is used in safety critical application field. This paper compares two bearingless slice machines, conventional permanent magnet bearingless slice machine and fault-tolerant permanent magnet bearingless slice machine, from fault-tolerant capability, suspension and drive performance points of view. Due to introduction of fault-tolerant stator structure, a optimization method for reduction of total harmonic distortion(THD) of back-EMF and electromagnetic coupling between different phases is proposed. Then, some relevant performance comparison, such as fault-tolerant performance, suspension performance as well as drive torque performance, is analyzed by finite element analysis. Finally, several design considerations are presented as guideline for design of bearingless slice machines with fault-tolerant stator structure.
BibTeX:
@inproceedings{ISMB14_20,
  author = {Qiang Ding and Guyu Wu and Zhiquan Deng and Xiaolin Wang},
  title = {Influence of Fault-Tolerant Stator Structure on Performance of Permanent Magnet Bearingless Slice Machines},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_20.pdf}
}
2014 Gerami, A., Allaire, P. and Fittro, R. Modeling and Control of Magnetic Bearings with Nonlinear Magnetization Proceedings of ISMB14  
Abstract: In this paper a nonlinear modeling approach is proposed to operate magnetic bearings above the linear range and near the material saturation point. The goal is to get higher load capacity from an existing AMB system by just changing the software. In order to do this, the system should be operated in the nonlinear region of the magnetization curve and therefore should be modeled nonlinearly. Simulation results show approximately twice the force capability. The controller designed using this approach has a much better transient response and domain of attraction.
BibTeX:
@inproceedings{ISMB14_21,
  author = {Ali Gerami and Paul Allaire and Roger Fittro},
  title = {Modeling and Control of Magnetic Bearings with Nonlinear Magnetization},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_21.pdf}
}
2014 Pennander, L.-O. Recent Development of Soft Magnetic Composite Materials and its Application Proceedings of ISMB14  
Abstract: This paper explores recent material development for Soft Magnetic Composites (SMC) which are based on pure iron metal powders combined with inorganic resistive coatings. SMC components are manufactured by compaction in a shaped tool followed by heat-treatment of the component for stress relaxation and to reach optimal magnetic and mechanical performance. The recently developed Somaloy(R) 5P SMC materials are presented and compared to former technology. The unique combination of material properties and manufacturing process is here concluded to enable possibilities to realize compact and efficient high-frequency electromagnets, a technique that can be an interesting opportunity for large volume, cost efficient magnetic bearings and bearingless applications.
BibTeX:
@inproceedings{ISMB14_22,
  author = {Lars-Olov Pennander},
  title = {Recent Development of Soft Magnetic Composite Materials and its Application},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_22.pdf}
}
2014 Lapotre, B., Takorabet, N., Tabar, F.M., Lateb, R. and Silva, J.D. Radial Force Modeling of bearingless Motors Based on, Spectral Analysis of Field Sources Proceedings of ISMB14  
Abstract: This paper proposes a global harmonic analysis of a multiphase bearingless PM-motor topology to determine the radial force by considering normal and tangential field components. This allows establishing the semi-analytical expressions of the radial force considering the location of field origin. The accuracy of the model is verified by full FEM model using a statistic approach. The semi-analytic model allows predicting the force waveforms according t the stator-rotor topology. The analysis of two specific topologies is performed and highlights the origin of force ripples. The fastness of this semi-analytical model makes it suitable to implement in a design optimization process.
BibTeX:
@inproceedings{ISMB14_23,
  author = {Blaise Lapotre and Nourddine Takorabet and Farid Meibody Tabar and Ramdane Lateb and Joaquim Da Silva},
  title = {Radial Force Modeling of bearingless Motors Based on, Spectral Analysis of Field Sources},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_23.pdf}
}
2014 Felscher, P., Baumann, K. and Alber, O. Active Magnetic Bearings As a Tool for Parameter Identification of Journal Bearings Proceedings of ISMB14  
Abstract: In this overview, it is presented how Active Magnetic Bearings (AMBs) can successfully be used for the measurement of equilibrium positions and the identification of stiffness and damping coefficients of journal bearings. Therefore, the theory of force measurements in AMBs by using either a theoretical or an experimentally derived relation is provided. Different operation modes of AMBs are considered, including the operation as a magnetic actuator. The successful parameter identification of journal bearing properties using AMBs is demonstrated by measurements.
BibTeX:
@inproceedings{ISMB14_24,
  author = {Patrick Felscher and Katrin Baumann and Oliver Alber},
  title = {Active Magnetic Bearings As a Tool for Parameter Identification of Journal Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_24.pdf}
}
2014 Zhou, L., Nejad, M.I. and Trumper, D. Magnetically Suspended Reaction Sphere with One-Axis Hysteresis Drive Proceedings of ISMB14  
Abstract: We have designed, built and tested a magnetically suspended reaction sphere with one-axis hysteresis drive (1DMSRS) in the Precision Motion Control Lab at MIT. This project is aiming at two goals: (a) exploring the possible design of a magnetically suspended reaction sphere for small spacecraft’s attitude control; and (b) evaluating the performance of a hysteresis motor for the reaction wheel/sphere application. The 1D-MSRS is a motor with spherical rotor, which is magnetically suspended in all translational directions, and is driven by hysteresis motor about vertical axis. For the suspension of the sphere, single dimensional magnetic levitation in vertical direction and bearingless motor around the rotor are combined. An equivalent circuit model of the hysteresis motor is used to analyze the motor’s dynamic behavior. Good agreements between computed and measured motor performance validates the model, which provides a useful simulation tool for further MSRS modeling and control. Test results of the 1D-MSRS show that a starting torque of 8.15 mNm is achieved at 0.7 A zero-peak excitation current, and with this excitation the sphere can run up to 12,000 rpm synchronously in lab with the existence of air drag.
BibTeX:
@inproceedings{ISMB14_25,
  author = {Lei Zhou and Mohammad Imani Nejad and David Trumper},
  title = {Magnetically Suspended Reaction Sphere with One-Axis Hysteresis Drive},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_25.pdf}
}
2014 Lopes, M., Sotelo, G.G., Rodriguez, E. and Stephan, R.M. Experimental Tests and Simulations to the Design of an Electrodynamic Bearing Proceedings of ISMB14  
Abstract: This paper describes an electrodynamic suspension system built with permanent magnets and aluminum plates. Initially, a simple case was studied to demonstrate the behavior of the levitation and drag forces for different conditions, such as air gap, angular velocity and thickness of the aluminum target. In the second part, numerical and experimental tests were performed to design an homopolar electrodynamic bearing (EDB). Forces obtained with eccentric operation as well as different rotor radial velocities are presented.
BibTeX:
@inproceedings{ISMB14_26,
  author = {Marcelo Lopes and Guilherme G. Sotelo and Elkin Rodriguez and Richard M. Stephan},
  title = {Experimental Tests and Simulations to the Design of an Electrodynamic Bearing},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_26.pdf}
}
2014 Filatov, A. and Hawkins, L. Comparative Study of Axial/Radial Magnetic Bearing Arrangements for Turbocompressor Applications Proceedings of ISMB14  
Abstract: This article presents results of a comparative study of different radial/axial actuator solutions for an Active Magnetic Bearing (AMB) system in a real-life turbocompressor application.
BibTeX:
@inproceedings{ISMB14_27,
  author = {Alexei Filatov and Larry Hawkins},
  title = {Comparative Study of Axial/Radial Magnetic Bearing Arrangements for Turbocompressor Applications},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_27.pdf}
}
2014 Yang, G., Shi, Z., Liu, X. and Zhao, J. Research and Experiment of Auxiliary Bearings with No Lubrication for Helium Blower of HTR-10 Proceedings of ISMB14  
Abstract: The auxiliary bearing is one of the important parts for the active magnetic bearing (AMB). A new auxiliary bearing design with no lubrication is proposed in this paper. This auxiliary bearing is composed of angular contact ceramic ball bearing. Two pairs of bearing will be distributed on both ends of the rotor. Each pair of bearing arrangement is face to face. Oil or grease will not be applied in this auxiliary bearing. But dry lubrication with MoS2 will be used in this bearing. This auxiliary bearing will be applied in the helium blower of 10MW high-temperature gas-cooled reactor (HTR-10). Oil or grease can’t be used in the primary loop of the HTR-10. The auxiliary bearing is used to support the blower rotor when the AMB fails to work. It must support the dropping rotor and bear the great impact force and friction heat. It is difficult to analyze the falling course of the rotor. There are two difficult problems to solve for the design of auxiliary bearing, including great impact force and friction heat. The preliminary analysis of the rotor was done. The impact force of the auxiliary bearing was computed for the axial and radial impact load by the finite element method. The temperature field will be analyzed and studied also in this paper. The auxiliary bearing’s life will be evaluated. The scheme of auxiliary bearing and the simulation results offer the important theoretical base for this new auxiliary bearing style, and offer the protector design of the helium blower with AMB for HTR-10.
BibTeX:
@inproceedings{ISMB14_28,
  author = {Guojun Yang and Zhengang Shi and Xingnan Liu and Jingjing Zhao},
  title = {Research and Experiment of Auxiliary Bearings with No Lubrication for Helium Blower of HTR-10},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_28.pdf}
}
2014 Hutterer, M., Hofer, M., Nenning, T. and Schrödl, M. LQG Control of an Active Magnetic Bearing with a Special Method to Consider the Gyroscopic Effect Proceedings of ISMB14  
Abstract: It could be very difficult to find an acceptable feedback path for coupled differential equations like a FIVE degree of freedom (DOF) AMB system. This paper describes a linear quadratic Gaussian (LQG) approach on this problem. Due to the time variant gyroscopic part of the AMB system equation the controller could only be optimized for a specific angular velocity. For this reason a time variant state feedback is developed and added to the LQG controller in a way that the system is nearly equal for all angular velocities. The feedback matrix which is the result of the LQG problem uses all feedback terms. Compared to a decentralized controller which only uses the diagonal terms, the LQG method also uses the cross feedback terms which are able to provide instability. After developing the LQG method was compared to a decentralized PID controller.
BibTeX:
@inproceedings{ISMB14_29,
  author = {Markus Hutterer and Matthias Hofer and Thomas Nenning and Manfred Schrödl},
  title = {LQG Control of an Active Magnetic Bearing with a Special Method to Consider the Gyroscopic Effect},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_29.pdf}
}
2014 Zhang, K., Dai, X. and Dong, J. An Energy Storage Flywheel Supported by Hybrid Bearings Proceedings of ISMB14  
Abstract: Energy storage flywheels are important for energy recycling applications such as cranes, subway trains. In a petroleum field, a drilling platform runs with big load variation. A vertical flywheel energy storage system had been tested to stabilize the load fluctuation and proved its effectiveness. To improve bearing life and reliability, a new flywheel bearing system was designed. The key was the use of hybrid bearings including an axial permanent magnetic bearing (PMB), a lower end ball bearing and an upper end active magnetic bearing (AMB). The design effectively combined advantages of the different bearings. The original upper ball bearing was replaced with the AMB to avoid the use of a lubrication system for it and improve the damping ability for the rotor vibration modes. The vibration mode and the harmonic response were provided in the rotor dynamic analysis for the new flywheel rotor. The analysis results proved that the new rotor structure and the AMB design were appropriate.
BibTeX:
@inproceedings{ISMB14_3,
  author = {Kai Zhang and Xingjian Dai and Jinping Dong},
  title = {An Energy Storage Flywheel Supported by Hybrid Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_3.pdf}
}
2014 Pilat, A. Active Magnetic Bearing Interdisciplinary Design Modelling and Control Tool Proceedings of ISMB14  
Abstract: This elaboration presents a modern approach in the field of active magnetic bearing design based on computations supported by partial differential equations (PDEs) and ordinary differential equations (ODEs). The magnetic field problems are solved using the finite element method (FEM), while the levitating rotor motion is calculated using ODEs. The novel Active Magnetic Bearing Interdisciplinary Design Modelling and Control (AMBIDMC) study tool was developed customising COMSOL Multiphysics and MATLAB software. This paper summarises the author’s recent work in the field of integrated active magnetic levitation (AML) systems design and modelling including control and motion dynamics. A discussion of the features and limitations of the field of control systems is provided in this paper, showing how the developed model can be useful for controller studies. The discussion is illustrated by simulation data collected from working virtual prototypes.
BibTeX:
@inproceedings{ISMB14_30,
  author = {Adam Pilat},
  title = {Active Magnetic Bearing Interdisciplinary Design Modelling and Control Tool},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_30.pdf}
}
2014 Liu, S., Bian, Z., Fan, Y. and Zhang, Y. Zero-Power Control for Magnetic Bearings in Artificial Heart Pumps Proceedings of ISMB14  
Abstract: Artificial heart pump is a new approach to the treatment of heart failure, and the main representative of the third generation of pump is the application of the magnetic suspension or other suspension technology. Energy saving operation of artificial heart pump is very important. This paper studies the application of zero power control in the artificial heart pump. The model of zero power controller and operation theory is presented, and the stiffness characteristic of rotor under zero power control is analyzed. The control method to change equivalent stiffness of rotor system is given according to suspension position, verifying the results.
BibTeX:
@inproceedings{ISMB14_32,
  author = {Shuqin Liu and Zhongguo Bian and Youpeng Fan and Yunpeng Zhang},
  title = {Zero-Power Control for Magnetic Bearings in Artificial Heart Pumps},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_32.pdf}
}
2014 Li, D. and Liu, S. Magnetic Bearing Rotor Vibration Analysis Based on Harmonic Wavelet Transform Proceedings of ISMB14  
Abstract: Analysis of the magnetic bearing rotor vibration is the base of the optimizing design, supervise and diagnosis of the magnetic bearing. Harmonic wavelet package was used for the analysis of the vibration signal, the 1 dimension time domain signal was mapped to 2 dimension time-frequency plane, and the 3 dimension time frequency domain energy graph was constructed, then the analysis of the rotor vibration became intuitionistic and convenient. Via analysis of the time-frequency graph, the vibration in each time and each frequency was obtained. After the feature extraction from the time-frequency graph, the supervise and the diagnosis of the magnetic bearing can be realized.
BibTeX:
@inproceedings{ISMB14_33,
  author = {Deguang Li and Shuqin Liu},
  title = {Magnetic Bearing Rotor Vibration Analysis Based on Harmonic Wavelet Transform},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_33.pdf}
}
2014 He, Y., Sun, Z., Zhao, J., Shi, Z. and Shi, L. Comparison of a Model-Based and a Model-Free Unbalance Control Methods in Magnetic Bearing System Proceedings of ISMB14  
Abstract: Synchronous vibration caused by rotor imbalance is an obvious vibration problem in rotating machinery. Since active magnetic bearing has been proved to be an effective approach to solve this problem, many researchers have proposed various methods to reduce synchronous vibration and those methods can be classified into two categories: model-based method and mode-lfree method. In the paper, we use a model-free method, iterative learning control (ILC) and a model-based adaptive forced balancing methods (MBAFB) to attenuate synchronous vibration respectively and then compare their performances in several aspects. The results of this paper can provide references for the users to choose an appropriate unbalance control algorithm.
BibTeX:
@inproceedings{ISMB14_34,
  author = {Ying He and Zhe Sun and Jingjing Zhao and Zhengang Shi and Lei Shi},
  title = {Comparison of a Model-Based and a Model-Free Unbalance Control Methods in Magnetic Bearing System},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_34.pdf}
}
2014 Jayawant, R. and Davies, N. Field Experience with Automated Commissioning Tools in Both Remote and Local Commissioning of Active Magnetic Bearing Systems Proceedings of ISMB14  
Abstract: This paper describes field experience with 3rd generation AMB automated commissioning tools. This covers experience on “first of class” machinery on sites where both AMB specialists were present using the automated commissioning tools and other installations where no AMB specialist was present and all commissioning was conducted by remote guidance of local non-specialist staff and remote use of automated commissioning tools.
BibTeX:
@inproceedings{ISMB14_35,
  author = {Richard Jayawant and Nigel Davies},
  title = {Field Experience with Automated Commissioning Tools in Both Remote and Local Commissioning of Active Magnetic Bearing Systems},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_35.pdf}
}
2014 Kumar, P. and Jayawant, R. Design Synthesis and Experimental Validation of an AMB Controller with a Power Dense Amplifier for Retrofit Applications Proceedings of ISMB14  
Abstract: This paper describes the design, development and validation of a high power amplifier used to up-rate the axial power amplifiers of a standard AMB controller. The VA rating of the amplifiers was doubled whilst maintaining the original footprint of the amplifier. The thermal management and other constructional challenges presented by such up-rating and high power density are discussed, together with some of the techniques used to overcome them. This up-rated system is suitable for retrofit applications where the controller is coupled to pre-existing AMB hardware. Preliminary results from such an installation are presented.
BibTeX:
@inproceedings{ISMB14_36,
  author = {Praveen Kumar and Richard Jayawant},
  title = {Design Synthesis and Experimental Validation of an AMB Controller with a Power Dense Amplifier for Retrofit Applications},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_36.pdf}
}
2014 Nenning, T., Hofer, M., Hutterer, M. and Schrödl, M. Statistic Errors of Different Inform Evaluation Methods Applied to Magnetic Bearings Proceedings of ISMB14  
Abstract: Active magnetic bearings offer many advantages compared to conventional bearings. But due to economic reasons their field of application is relatively small. Self-sensing magnetic bearings can contribute to a significant decrease of the system costs, of course at limited accuracy in position detection compared to systems with sensors. The later on described INFORM method is one approach to self-sensing magnetic bearings. The position depending reluctance is measured through high frequent voltage injections and the resulting current slope. This paper discusses how different evaluation methods capable of calculating the current slope from the raw measurement data, differ in sensitivity and noise rejection. Therefore first the theoretical background of the used self-sensing method is explained. Next the error propagation of different evaluation methods is analysed and finally compared to measurements.
BibTeX:
@inproceedings{ISMB14_37,
  author = {Thomas Nenning and Matthias Hofer and Markus Hutterer and Manfred Schrödl},
  title = {Statistic Errors of Different Inform Evaluation Methods Applied to Magnetic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_37.pdf}
}
2014 Nenning, T., Hofer, M., Hutterer, M. and Schrödl, M. Setup with Two Self-Sensing Magnetic Bearings Using Differential 3-Active Inform Proceedings of ISMB14  
Abstract: This paper describes how a rotor with two radial self-sensing Hybrid Magnetic Bearings (HMB) with a novel self-sensing method is set up. Replacing position sensors with low cost alternatives currently is a broad field of research as it allows to decrease costs significantly. First the adapted version of the INFORM method in use is described in detail, explaining the advantages compared to the classic INFORM. Next the results of a 3D electro-magnetic finite element simulation are shown. The simulation was used to find an optimal geometry concerning the mutually exclusive goals of maximising bearing force and sensitivity / linearity of the INFORM method. Finally the simulation results are compared to measurements on the prototype.
BibTeX:
@inproceedings{ISMB14_38,
  author = {Thomas Nenning and Matthias Hofer and Markus Hutterer and Manfred Schrödl},
  title = {Setup with Two Self-Sensing Magnetic Bearings Using Differential 3-Active Inform},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_38.pdf}
}
2014 Komori, M., Takase, S., Nemoto, K., Sakai, N. and Asami, K.-I. Innovative Magnetic Levitation System by Using Persistent Current in Superconducting Coil Proceedings of ISMB14  
Abstract: Superconducting technique is applied to the levitation system. Persistent current in superconducting coil and control current in copper coil are used for levitating object and controlling object, respectively. The system is composed of a superconducting coil, a copper coil, a levitated object, a photo sensor, a PD controller, and power amplifiers. In this paper, basic study on superconducting coil and solenoid coil, and the dynamic characteristics of levitated object are performed. This may be the first trial that superconducting coil is used for magnetic levitation.
BibTeX:
@inproceedings{ISMB14_39,
  author = {Mochimitsu Komori and Shingo Takase and Kaoru Nemoto and Nobuo Sakai and Ken-Ichi Asami},
  title = {Innovative Magnetic Levitation System by Using Persistent Current in Superconducting Coil},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_39.pdf}
}
2014 Defoy, B., Alban, T. and Mahfoud, J. Energy Cost Assessment of the Active Control of a the Flexible Rotor Supported by AMB Proceedings of ISMB14  
Abstract: From a designer point of view, optimizing the energy necessary for the control is an important element that could lead to downsize the control cabinet and to an increase of margins according to power amplifier capabilities. Also, reducing the energy used, generates a less significant environmental impact. Two fuzzy logic based controllers were developed and assessed. First, the “Mechanical” performances are compared with respect to an augmented PID controller. Then, the energy necessary for the control is compared.
BibTeX:
@inproceedings{ISMB14_4,
  author = {Benjamin Defoy and Thomas Alban and Jarir Mahfoud},
  title = {Energy Cost Assessment of the Active Control of a the Flexible Rotor Supported by AMB},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_4.pdf}
}
2014 Smirnov, A., Pesch, A., Wroblewski, A., Pyrhönen, O. and Sawicki, J.T. Feedback Compensation of Tool Deflection in a High Speed AMB Machining Spindle Proceedings of ISMB14  
Abstract: This paper describes a method for compensation of tool tip deflection in a high-speed, magnetically levitated, machining spindle. The proposed method utilizes measurements from the AMB sensors to estimate forces and calculate the resulting tool deflections. The deflections are then compensated online with a feedback signal that changes the loaded tool tip’s position. The modeled results show significant performance improvements, which are experimentally validated.
BibTeX:
@inproceedings{ISMB14_40,
  author = {Alexander Smirnov and Alexander Pesch and Adam Wroblewski and Olli Pyrhönen and Jerzy T. Sawicki},
  title = {Feedback Compensation of Tool Deflection in a High Speed AMB Machining Spindle},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_40.pdf}
}
2014 Han, C., Xu, L. and Lin, Y. Researches on Substrates of High Temperature Eddy Current Sensor Proceedings of ISMB14  
Abstract: In this paper, substrates of eddy current sensor were composed by silver films and glass ceramic disks, all of these can resist high temperature . The thin silver films were deposited by radio frequency magnetron sputtering on machinable glass ceramic at room temperature. Variations of sputtering power, bios voltage and power density were carried out for each deposition, then parts of as-deposited samples were subjected to annealing at 600 ? within a vacuum chamber. Structural properties were studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). It was shown that structural properties had a strong dependency on sputtering power and annealing temperature. Electrical contact resistance measured by a four point probe instrument was directly affected by the thickness of films. It was also found that the film conductivity, especially in thinner films, was improved by the increasing grain size. Further more, the film adhesion was observed by scratch tests experiment. Finally, the subsequent processes of high temperature eddy current sensor were introduced.
BibTeX:
@inproceedings{ISMB14_41,
  author = {Chao Han and Longxiang Xu and Yingzhe Lin},
  title = {Researches on Substrates of High Temperature Eddy Current Sensor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_41.pdf}
}
2014 Zhang, Y., Fang, J., Jiang, Y., Zhou, J. and Chen, Q. Analysis of Nonlinear Behavior in Power Amplifier of AMB System Proceedings of ISMB14  
Abstract: In order to make the AMB system satisfied the high energy-efficiency demands, the nonlinear behavior of H-bridge inverter, which is a power amplifier for AMB system, is studied in this paper. The discrete mapping model of the H-bridge inverter is established with some improvement using stroboscopic method. Based on this model, the dynamic evolution process of the inverter from stable state to chaos is directly exhibited, and the stable variation ranges of feedback gain and coil inductances are determined. Furthermore, a new simulation nonlinear model for an AMB system based on nonlinear H-Bridge inverter amplifier is set up, the influence of H-bridge inverter’s nonlinear behavior on the entire AMB system with two alternate change parameters is investigated. The simulation and experimental results demonstrate the existence of chaos phenomenon in AMB system and provide a stable range for AMB coil and control system design. The new AMB system model may have some benefits to the study of chaos control method for avoiding bifurcation and chaos phenomenon in AMB system.
BibTeX:
@inproceedings{ISMB14_42,
  author = {Yin Zhang and Jiancheng Fang and Yinxiao Jiang and Jinxiang Zhou and Qi Chen},
  title = {Analysis of Nonlinear Behavior in Power Amplifier of AMB System},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_42.pdf}
}
2014 Lee, K.-C., Baek, J.-Y., Kim, J.-W., Ahn, M.-H., Jung, T.-U. and Lee, M.-C. Design of Electromagnetic Levitation Linear Bearing for FPD Glass Delivery Applications Proceedings of ISMB14  
Abstract: In flat panel display (FPD) manufacturing, especially in next-generation organic light-emitting diode (OLED) display manufacturing, a high-weighted glass carrying tray is required to be position servo-controlled precisely in long range of vacuum process line without mechanical contact. So special contactless linear bearing, which is called a electromagnetic levitation linear bearing (ELLB) is suggested in this paper. It can expend its operating distance by adding series of electro-magnets and shifting the electromagnets by section switching algorithms suggested in reference [12]. In order to prove the feasibility of the ELLB, a test setup with specially designed ELLB is made-up and the performance of it is observed. With the proposed ELLBs and proper linear propulsion system, the glass-carrier system in vacuum FPD manufacturing process line is expected to be constructed easily in the near future.
BibTeX:
@inproceedings{ISMB14_43,
  author = {Ki-Chang Lee and Jun-Young Baek and Ji-Won Kim and Min-Hyuk Ahn and Tae-Uk Jung and Min-Cheol Lee},
  title = {Design of Electromagnetic Levitation Linear Bearing for FPD Glass Delivery Applications},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_43.pdf}
}
2014 Liu, X., Mo, N. and Zhou, Y. The Comparison of excitation source for sensors of the AMB system in HTGR Proceedings of ISMB14  
Abstract: Nowadays the High Temperature Gas-Cooled Reactor (HTGR) is developed widely over the world. A helium turbine of a 10 MW HTGR test module reactor with the core made of spherical fuel elements is under research at the Institute of Nuclear and New Energy Technology of Tsinghua University in China. In HTGR, the magnetic bearings are widely applied, where the rotating machineries are running under highly pure helium environment. Compared with conventional bearings, Active Magnetic Bearings (AMBs) possess several attractive advantages, such as contact-free, no-lubricating and active damping vibration. The sensors are the key components of the AMBs system and are responsible for measuring the position and movement of the rotor, the operating temperature and so on. In order to operate the sensors successfully, a stable and efficient excitation source is needed. The paper will present the design, simulation and test of Class AB and Class D type power amplifier excitation sources for the sensors of the AMBs system.
BibTeX:
@inproceedings{ISMB14_44,
  author = {Xiaohan Liu and Ni Mo and Yan Zhou},
  title = {The Comparison of excitation source for sensors of the AMB system in HTGR},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_44.pdf}
}
2014 Kailasan, A., Dimond, T. and Allaire, P. Energy Storage Flywheel Magnetic Bearing System - Magnetic Linear Circuit Vs. 3-D Finite Element Model Plus Electrical and Thermal Modeling Proceedings of ISMB14  
Abstract: A 1 kW-hr (3.6 MJ) energy storage flywheel with a design operating speed of 40,000 rpm and an inside-out flywheel has been designed and optimized. It is supported in two thrust and two radial active magnetic bearings. The purpose of this paper is to present the active magnetic bearing system modeling including the magnetic analysis. At the design stage, there are two ways to evaluate the magnetic bearing properties: linear circuit model or finite element model. The linear circuit models are simple lumped mass models. The finite element model discretizes the bearing geometry and the surrounding space and requires a great deal more work. There are not many full 3-D finite element magnetic bearing systems that have been fully compared to the equivalent linear circuit model. There are legitimate questions about accuracy of magnetic bearing modeling results. This paper considers these two approaches to compare the results for a realistic energy storage flywheel design. If the differences are large, it is expected that the 3-D finite element model is more likely to be accurate. This paper documents the differences for the flywheel magnetic bearing designs. The linear circuit model prediction of axial force capacity was 17% lower and the prediction of coil inductance was 8% lower than the predictions from 3-D finite element model. The linear circuit model of the radial bearing underestimated the force capacity by 14% and underestimated the inductance by 8.5% when compared to the 3D finite element model. Values were also compared for the open loop stiffness, current gain and force slew rate for both bearing designs. These relatively large differences in magnetic bearing performance parameters obtained between the linear circuit model and the 3-D finite element model, shows that the linear circuit model is not very accurate. Thus, the concern is that designing and optimizing a complex magnetic bearing supported device requires 3-D finite element modeling at the design stage. The flywheel has not been constructed and the magnetic bearings are thus not available for testing. It is hoped that this can be future work.
BibTeX:
@inproceedings{ISMB14_45,
  author = {Arunvel Kailasan and Tim Dimond and Paul Allaire},
  title = {Energy Storage Flywheel Magnetic Bearing System - Magnetic Linear Circuit Vs. 3-D Finite Element Model Plus Electrical and Thermal Modeling},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_45.pdf}
}
2014 Mendes, R.U., Daniel, G.B., de Castro, H.F. and Cavalca, K.L. Application of a Magnetic Actuator As an External Excitation Source in Fault Detection Proceedings of ISMB14  
Abstract: Rotating machinery covers a broad range of industrial applications. Consequently, unexpected failures may lead to suddenly manufacturing break-off involving high maintenance costs. The most common faults in such machines introduce anisotropy to the system causing changes in its modal parameters and increasing the response backward component. Modal analysis methods can be used to identify changes in the machine behavior and foresee incipient faults. This paper presents the time domain Multiple Output Backward Autoregression (MOBAR) method and discusses its advantages over frequency domain methods on field tests in industry. For the MOBAR method, a tuned non-synchronous excitation called blocking test is applied to the shaft using a magnetic actuator, and when the excitation is turned off, the decay response is used to estimate natural frequencies of the system and the corresponding modal damping. The changing of these parameters can be used to predict system failures. To demonstrate the usability of electromagnetic actuators to apply this method for fault diagnosis and identification, a case study is presented in which the directional coordinates modal parameters are identified for a rotor supported by journal bearings using the MOBAR technique.
BibTeX:
@inproceedings{ISMB14_46,
  author = {Ricardo Ugliara Mendes and Gregory Bregion Daniel and Helio Fiori de Castro and Katia Lucchesi Cavalca},
  title = {Application of a Magnetic Actuator As an External Excitation Source in Fault Detection},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_46.pdf}
}
2014 David, D., Santisteban, J. and Gomes, A.C.D.N. Interconnected Four Poles Magnetic Bearings Simulations and Testing Proceedings of ISMB14  
Abstract: This article proposes and analyses a new idea to be used in magnetic bearings. It is an adaptation of a structure that has already worked successfully in split-winding self-bearing motors. Preliminary theoretical results predict that a greater equivalent stiffness could be achieved when compared with the values associated with the traditional active magnetic bearing conception in the literature.
BibTeX:
@inproceedings{ISMB14_47,
  author = {Domingos David and Jose Santisteban and Afonso Celso Del Nero Gomes},
  title = {Interconnected Four Poles Magnetic Bearings Simulations and Testing},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_47.pdf}
}
2014 Tian, Y., Sun, Y. and Yu, L. Advanced Controller of a Hybrid Foil-Magnetic Bearing Proceedings of ISMB14  
Abstract: A hybrid foil-magnetic bearing (HFMB) is combination of a gas foil bearing (GFB) and a active magnetic bearing (AMB), which takes advantages of both bearings while compensating each other’s weaknesses. It is a solution of friction and wear of the GFBs at low speeds and limited load capacity of the AMBs. Furthermore, load sharing and control of dynamics can be achieved in a hybrid foilmagnetic bearing. However, in order to achieve the ideal performances of the HFMBs, an advanced controller must be designed based on the static and dynamic performances of the HFMBs. Since the AMBs are ‘smart’ devices that the working condition can be measured and actively controlled, it is quite natural to design an advanced controller for the HFMBs to use the AMBs to identify the characteristics of the GFBs and with the function of load sharing between the GFBs and the AMBs. In this paper, a 4-DOF model of bearing-rotor system supported by two HFMBs was established firstly, and then an advanced controller with the function of identification and load sharing was presented. Finally, experiments were done on a test rig whose rotor is supported by two journal HFMBs and a thrust AMB. The test results show that when change the load shared by the GFBs and the AMBs, advanced controller can find the new proper working position of the HFMBs rapidly and smoothly. More importantly, HFMBs with advanced controller based on the identified characteristics of GFBs can work steadily at the speed range of 0 2,2000r/min.
BibTeX:
@inproceedings{ISMB14_48,
  author = {Ye Tian and Yanhua Sun and Lie Yu},
  title = {Advanced Controller of a Hybrid Foil-Magnetic Bearing},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_48.pdf}
}
2014 Liu, P., Zhao, L., He, Y. and Zhang, K. Force Free Control in Active Magnetic Bearing Systems for the Magnetically Suspended Compound Molecule Pump Proceedings of ISMB14  
Abstract: A force free control method is studied based on the active magnetic bearings (AMBs) system of the magnetically suspended compound molecule pump. This method uses the feedforward strategy. The output signals generated with the least mean square (LMS) algorithm are the same as synchronous disturbances, which are caused by unbalance forces. So through this approaches, the controller need not respond to synchronous disturbances. This method can let the rotor rotate around its inertia axis and eliminate the synchronous disturbances of the currents in the electromagnet windings to significantly attenuate the mechanical vibration of the shell. The experimental results verify that the proposed approach is significantly minimized the amplitude of the shell vibration of the magnetically suspended compound molecule pump, which will provide good experience and design references for the future application of the AMBs in the molecule pump.
BibTeX:
@inproceedings{ISMB14_49,
  author = {Pingfan Liu and Lei Zhao and Ying He and Kai Zhang},
  title = {Force Free Control in Active Magnetic Bearing Systems for the Magnetically Suspended Compound Molecule Pump},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_49.pdf}
}
2014 Liu, B., Sjöberg, J. and Laiho, A. Optimization Based AMB Controller Design and Verification for Flexible Rotors Proceedings of ISMB14  
Abstract: Engineering costs especially for controller design are substantial and obstruct active magnetic bearings (AMBs) for broader industrial applications. An optimization based AMB controller design method is developed to solve this problem. The optimization criteria are selected to describe AMB practical performance. Controller components are chosen considering that parameters can be manually interpreted and modified onsite for commissioning. A multi-objective genetic algorithm (MOGA) toolbox is used to tune these controller component parameters to minimize the design criteria automatically. The method has been verified in a controller design process for an AMB levitated machine. With this method, the engineering cost for controller design can be reduced significantly.
BibTeX:
@inproceedings{ISMB14_5,
  author = {Bin Liu and Johan Sjöberg and Antti Laiho},
  title = {Optimization Based AMB Controller Design and Verification for Flexible Rotors},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_5.pdf}
}
2014 Rodriguez, E., de Santiago, J., Perez-Loya, J., Costa, F., Sotelo, G.G., Oliveira, J.G. and Stephan, R.M. Analysis of Passive Magnetic Bearings for Kinetic Energy Storage Systems Proceedings of ISMB14  
Abstract: This paper describes a passive magnetic bearing system intended to be used in a flywheel. The upper bearing consists of two rings of permanent magnets operating as a radial bearing. The lower bearing consists of high temperature superconductors in the stator and a permanent magnet cylindrical disk in the rotor, which contributes to the radial and axial stability of the system. Those bearings have been tested in an experimental rig specially designed for it. Measurements of the radial and axial forces, both static and dynamic, for different gaps are presented in this paper
BibTeX:
@inproceedings{ISMB14_50,
  author = {Elkin Rodriguez and Juan de Santiago and Jose Perez-Loya and Felipe Costa and Guilherme G. Sotelo and Janaina G. Oliveira and Richard M. Stephan},
  title = {Analysis of Passive Magnetic Bearings for Kinetic Energy Storage Systems},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_50.pdf}
}
2014 Hearn, C., Pratap, S., Chen, D. and Longoria, R. Superconducting Bearing Design for Outer Rotor Flywheel Using Lumped Parameter Techniques Proceedings of ISMB14  
Abstract: This paper describes the application of lumped parameter modeling techniques to designing high temperature superconducting bearings for outer-rotor flywheel energy storage systems. The lumped parameter models decrease computational time by 99% compared to Finite Element Analysis (FEM) without compromising fidelity needed to capture the non-linear and hysteretic force-displacement behavior between a levitated permanent magnet and bulk superconductor. The techniques formulated can be used to quickly evaluate lifting capacity and translational stiffness for a superconducting bearing design. The validity of the modeling approach has been verified by comparing results from FEM studies and experimental tests.
BibTeX:
@inproceedings{ISMB14_51,
  author = {Clay Hearn and Siddharth Pratap and Dongmei Chen and Raul Longoria},
  title = {Superconducting Bearing Design for Outer Rotor Flywheel Using Lumped Parameter Techniques},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_51.pdf}
}
2014 Ishino, Y., Takasaki, M. and Mizuno, T. Fablication of Non-Contact Carrier System Using Solar Magnetic Suspension Proceedings of ISMB14  
Abstract: A solar-powered magnetic suspension carrier system is fabricated which achieves noncontact power supply to the carrier. There are two conventional methods of supplying power to a carrier. One is through wires or contacts such as pantograph and the other is a battery in the carrier. However, the noncontact characteristics are lost in the former, and stations for charging the battery are necessary in the latter. These problems are overcome by the proposed carrier system using solar magnetic suspension that can achieve continuous levitation. In rooms like in factory, the generation of power by solar cells is low so that the magnetic suspension needs power saving. A zero power control system is applied to the suspension of the floator. In addition, low-power peripheral devices are also fabricated.
BibTeX:
@inproceedings{ISMB14_52,
  author = {Yuji Ishino and Masaya Takasaki and Takeshi Mizuno},
  title = {Fablication of Non-Contact Carrier System Using Solar Magnetic Suspension},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_52.pdf}
}
2014 Zhou, J., Fang, J., Zhang, Y. and Jiang, Y. Anti-Windup Control of Active Magnetic Bearings Subject to Voltage Saturation Proceedings of ISMB14  
Abstract: Active magnetic bearings (AMBs) have been widely applied in industrial rotating machinery. Power amplifier as an essential actuator of the AMB faces the limitation of DC bus voltage. A simple approach is to increase the voltage to a high value, but it has to deal with large current ripples and a low resolution. Other than the ordinary method, this paper addresses to the anti-windup control of AMB that aims to eliminate the adverse effect of the voltage saturation. The antiwindup algorithm is an addition to the nominal linear controller. And only when the saturation occurs is it activated. The stability is guaranteed by the procedure of calculating the linear matrix inequality (LMI) form of the regional Lyapunov stability. Simulation test is done to verify the proposed controller. Finally in the motor drive experiment, the axial AMB equipped in the prototype supports the thrust force. With the load changes, the performance of the anti-windup controller is demonstrated.
BibTeX:
@inproceedings{ISMB14_53,
  author = {Jinxiang Zhou and Jiancheng Fang and Yin Zhang and Yinxiao Jiang},
  title = {Anti-Windup Control of Active Magnetic Bearings Subject to Voltage Saturation},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_53.pdf}
}
2014 Toh, C.-S. and Chen, S.-L. Modeling and Control of a Hybrid Magnetic Bearing in a Ring-Type Flywheel System Proceedings of ISMB14  
Abstract: In this study, a hybrid magnetic bearing (HMB) is proposed for a ring-type flywheel system. The HMB is composed of passive and active units. The rotor weight will be fully supported by the lateral forces of the passive units. The other 4 DOFs will be levitated and controlled by the active units. We will first establish the magnetic force model of the passive and active units of the proposed HMB. With the magnetic force models in hand, a stabilizing levitation controller for the HMB is designed. Moreover, numerical simulation results verify the effectiveness of the controller.
BibTeX:
@inproceedings{ISMB14_54,
  author = {Chow-Shing Toh and Shyh-Leh Chen},
  title = {Modeling and Control of a Hybrid Magnetic Bearing in a Ring-Type Flywheel System},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_54.pdf}
}
2014 Stimac, G., Braut, S., Zigulic, R. and Skoblar, A. Robust Control and Loop Shaping Design with the Application to Flexible Rotor Levitated with AMBs Proceedings of ISMB14  
Abstract: The aim of this research is to ensure stable operation at a nominal rotation speed (above the first critical speed) of a flexible rotor levitated with active magnetic bearings (AMBs) and to guarantee good performance of the rotor/AMB system. Initially, minimizing the ITAE performance index, PID control system is designed to stabilize the rotor. The obtained transfer function is adopted as a compensator to shape the singular values of the nominal plant. By applying the Glover-McFarlane control method, a robust controller which includes coprime factor uncertainties is designed. The results show that the AMB system satisfies Zone A specifications defined by the ISO 14839 standard for newly commissioned machines with magnetic bearings.
BibTeX:
@inproceedings{ISMB14_55,
  author = {Goranka Stimac and Sanjin Braut and Roberto Zigulic and Ante Skoblar},
  title = {Robust Control and Loop Shaping Design with the Application to Flexible Rotor Levitated with AMBs},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_55.pdf}
}
2014 Zheng, S. and Feng, R. A Notch Filter for Magnetically Suspended Rotors Based on Rotating Coordinate Transformation Proceedings of ISMB14  
Abstract: Synchronous vibration are obstacles to the performance improvement of a rotating shaft supported by active magnetic bearings (AMBs). Based on the synchronous rotating coordinate transformation, this paper proposed a novel notch filter for the autobalancing of magnetically suspended rotors. After the analysis of the frequency characteristics of the novel notch filters, the calculating method of the convergence rate and comparison with the traditional notch filter are further investigated. Finally, the corresponding simulations and experiments are conducted. The results demonstrate that the novel notch filter has a good significant effect on the synchronous vibration of weakly gyroscopic rotors.
BibTeX:
@inproceedings{ISMB14_56,
  author = {Shiqiang Zheng and Rui Feng},
  title = {A Notch Filter for Magnetically Suspended Rotors Based on Rotating Coordinate Transformation},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_56.pdf}
}
2014 Lyu, X., Di, L., Yoon, S.Y., Lin, Z. and Hu, Y. Emulation of Energy Storage Flywheels on a Rotor-AMB Test Rig Proceedings of ISMB14  
Abstract: Because of their many appealing features, such as high specific energy, high specific power, ultra-compactness, short charging time (in minutes), long life span and no pollution, energy storage flywheels suspended on active magnetic bearings (AMBs) have drawn worldwide attention. In this paper, we use an existing rotor-AMB test rig to emulate the operation of energy storage flywheels suspended on AMBs. The test rig contains four active magnetic bearings, two located at the two ends of the rotor, one located at the rotor mid-span and the last located at the rotor quarter span. We will use the two magnetic bearings in the mid and quarter spans to emulate the negative stiffness of the generator and the gyroscopic effect of the flywheel disk. Simulation and experimental results are presented.
BibTeX:
@inproceedings{ISMB14_57,
  author = {Xujun Lyu and Long Di and Se Young Yoon and Zongli Lin and Yefa Hu},
  title = {Emulation of Energy Storage Flywheels on a Rotor-AMB Test Rig},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_57.pdf}
}
2014 Kasten, H. and Redemann, C. Influence on Unbalanced Magnetic Pull Proceedings of ISMB14  
Abstract: This article describes the effects of the unbalanced magnetic pull and the opportunities to suppress asymmetries of the air gap field.
BibTeX:
@inproceedings{ISMB14_58,
  author = {Henning Kasten and Christian Redemann},
  title = {Influence on Unbalanced Magnetic Pull},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_58.pdf}
}
2014 Basovich, S., Moha, T.B., Peretz, M., Arogeti, S. and Brand, Z. Switch-Mode Current Amplifier for Active Magnetic Bearings Proceedings of ISMB14  
Abstract: This paper presents the concept and the practical implementation of a switch-mode current amplifier for the use in Active Magnetic Bearings (AMB). The switch-mode amplifier consists of a full-bridge capable of operating in 2-level, 3- level or phase-shifted PWM mode. An optimal digital currentprogrammed mode controller lays out the foundations to a proximate-optimal, robust, large-signal dynamic response of the system under extreme cases of loading and parameters variations. In particular, the current amplifier developed is capable of following the desired reference for large inductance variations (due to displacement). The power stage combines a newly developed, efficient, passive-based current sensor that is capable of sensing bi-directional and near-zero currents, while being robust to external disturbances and maintaining simple and efficient structure. The presented current amplifier concept has been verified experimentally on a single-axis AMB platform using a dual channel amplifier prototype, controlled by a single 16 bit low-cost microcontroller.
BibTeX:
@inproceedings{ISMB14_59,
  author = {Sergei Basovich and Tomer Ben Moha and Mor Peretz and Shai Arogeti and Ziv Brand},
  title = {Switch-Mode Current Amplifier for Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_59.pdf}
}
2014 Xu, Y., Zhou, J., Di, L. and Xu, L. Active Magnetic Bearings for Rolling Element Bearings Outer Race Incipient Defect Diagnosis Proceedings of ISMB14  
Abstract: The active health monitoring of rotordynamic systems in the presence of bearing outer race defect is considered in this paper. The shaft is assumed to be supported by conventional mechanical bearings and an active magnetic bearing (AMB) is used in the mid of the shaft or outboard location as an actuator to apply constant force to the system. We present a nonlinear bearing-pedestal system model with the outer race defect under the AMB force. The nonlinear differential equations are integrated using the fourth-order Runge—Kutta algorithm in MATLAB and the simulation result is obtained. The simulation results show that the characteristic outer race defect signal is significantly amplified under the AMB force, which is helpful to improve the diagnosis accuracy of outer race defect.
BibTeX:
@inproceedings{ISMB14_6,
  author = {Yuanping Xu and Jin Zhou and Long Di and Longxiang Xu},
  title = {Active Magnetic Bearings for Rolling Element Bearings Outer Race Incipient Defect Diagnosis},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_6.pdf}
}
2014 Di, L., Zhou, J., Chen, C. and Lin, Z. Experimental Verification of a Rotor Unbalance Response Based Approach to the Identification of Magnetic Bearing Support Parameters Proceedings of ISMB14  
Abstract: The support parameters, the stiffness and damping coefficients, of active magnetic bearings (AMBs) have direct influence on the dynamic response and stability of a rotor bearing system. The unbalance response method is a simple but effective way to identify the AMB support parameters. In this paper, we present experimental verification of this identification method. We first briefly introduce the unbalance response method and the error response surface approach to rectifying the identification error induced by the rotor flexibility. The final AMB stiffness and damping coefficients are determined as the sum of the nominal values identified by the unbalance response method and the identification errors derived from the error response surfaces. We will then present the experimental verification of this combined unbalance response and error response surface identification method on a rotor AMB test rig. In order to verify the identification method, the parameters thus identified based on the experimental data are integrated with the rotor finite element model to form the rotor-AMB model. The model unbalance response is obtained through simulation and compared with experimentally measured unbalance response. The close agreement between the model unbalance response and the experimentally measured response demonstrates that the proposed method is effective in identifying the AMB support parameters.
BibTeX:
@inproceedings{ISMB14_60,
  author = {Long Di and Jin Zhou and Changli Chen and Zongli Lin},
  title = {Experimental Verification of a Rotor Unbalance Response Based Approach to the Identification of Magnetic Bearing Support Parameters},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_60.pdf}
}
2014 Ariga, Y., Saitoh, Y. and Watanabe, K. Controller Structure for Magnetic Bearing for Achieving Both Unbalance Suppression and Stabilization Proceedings of ISMB14  
Abstract: This study proposes a control system in which the controller structure is divided in consideration of the unstable zeros of the controller. This controller can both inhibit a sine wave disturbance intended to produce unbalanced vibrations and stabilize the system with desired bearing stiffness. The effectiveness of the proposed method is verified through a simulation.
BibTeX:
@inproceedings{ISMB14_61,
  author = {Yuichi Ariga and Yohei Saitoh and Keiji Watanabe},
  title = {Controller Structure for Magnetic Bearing for Achieving Both Unbalance Suppression and Stabilization},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_61.pdf}
}
2014 Sugimoto, H., Tanaka, S. and Chiba, A. Reduction of Rotor Vibration in Passively Stabilized Direction in Single-Drive Bearingless Motor Proceedings of ISMB14  
Abstract: In this paper, an improvement of the rotor vibration in one-axis actively positioned single-drive bearingless motor (SDBM) with repulsive passive magnetic bearings is presented. The SDBM has only one set of three-phase windings. It generates both torque and active axial force independently driven by only one three-phase inverter and one displacement sensor. Therefore, the single-drive bearingless motors have the advantages of low cost and small size. Only axial z-axis is actively positioned. The other axes, radial movements x and y, and tilting movements ? x and ? y, are passively stable. Therefore, in the one degree-of-freedom (1DOF) bearingless motor, vibrations in the radial and tilting directions are serious problem. In this paper, an improvement method of the radial vibration in the 1DOF SDBM is presented. The principle of the radial vibration generation is shown. In the experiment, it is found that a correction of the rotor rotational angular position is effective for the radial vibration reduction.
BibTeX:
@inproceedings{ISMB14_62,
  author = {Hiroya Sugimoto and Seiyu Tanaka and Akira Chiba},
  title = {Reduction of Rotor Vibration in Passively Stabilized Direction in Single-Drive Bearingless Motor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_62.pdf}
}
2014 Ueno, S., Fukuura, T. and Toan, T.V. A 5-DOF Active Controlled Disk Type PM Motor with Cylindrical Flux Paths Proceedings of ISMB14  
Abstract: This paper proposes a novel disk type permanent magnet motor, which actively controls 5 degrees of freedom of a flat rotor without any contact. The proposed motor consists of an Axial Self-bearing Motor (ASBM) and additional cylindrical flux paths. The axial force and motor torque are controlled by the rotating flux with the same number of poles of the rotor, and the tilt control torque is produced by the rotating flux with the two plus or two minus poles of the rotor. The radial force is produced by supplying direct current to the stator windings. The direct current produces the flux through the stator and the cylindrical flux path, then the radial force can be generated by the interaction of the rotor poles and the edge of the cylindrical flux path. This paper introduces the structure and principle of the proposed motor, and shows the results of the magnetic forces calculated by the numerical electromagnet analysis.
BibTeX:
@inproceedings{ISMB14_63,
  author = {Satoshi Ueno and Takuya Fukuura and Tran Van Toan},
  title = {A 5-DOF Active Controlled Disk Type PM Motor with Cylindrical Flux Paths},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_63.pdf}
}
2014 Uemura, Y., Nakahata, T. and Chiba, A. Vibration Suppression of A Middle-Point Current-Injection Type Bearingless Motor at 50000r/min Proceedings of ISMB14  
Abstract: With the developments of power electronics technology and increments of rotational speed of motors, a critical speed is one of the problems. Vibration of rotational shaft has been reported to be suppressed by magnetic force of bearingless motors. In general bearingless motors, motor windings and suspension windings are separately enclosed in the stator slot. For only vibration suppression at a critical speed, however, suspension windings are not used except the critical speed. In this paper, vibration suppression of a rotor shaft by a middle-point current-injection type bearingless motor at 50000 r/min is presented. This motor can generate the torque and the magnetic force by only one set of three-phase windings. The test results of the vibration suppression are presented.
BibTeX:
@inproceedings{ISMB14_64,
  author = {Yusuke Uemura and Takayuki Nakahata and Akira Chiba},
  title = {Vibration Suppression of A Middle-Point Current-Injection Type Bearingless Motor at 50000r/min},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_64.pdf}
}
2014 Impinna, F., Detoni, J.G., Tonoli, A. and Amati, N. Test and Theory of Electrodynamic Bearings Coupled to Active Magnetic Dampers Proceedings of ISMB14  
Abstract: Electrodynamic bearings (EDBs) are passive magnetic bearings that exploit the interaction between eddy currents developed in a rotating conductor and a static magnetic field to generate forces. Similar to other types of magnetic suspensions, EDBs provide contactless support, thus avoiding problems with lubrication, friction and wear. Electrodynamic bearings have also drawbacks such as the difficulty in insuring a stable levitation in a wide speed range. The paper presents a solution where the EDBs are coupled with active magnetic dampers (AMDs) to guarantee a stable levitation.
BibTeX:
@inproceedings{ISMB14_65,
  author = {Fabrizio Impinna and Joaquim Girardello Detoni and Andrea Tonoli and Nicola Amati},
  title = {Test and Theory of Electrodynamic Bearings Coupled to Active Magnetic Dampers},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_65.pdf}
}
2014 Mönch, I., Melzer, M., Bahr, F., Makarov, D., Hofmann, W. and Schmidt, O.G. Ultra-Thin and Flexible Hall Effect Sensorics Proceedings of ISMB14  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB14_66,
  author = {Ingolf Mönch and Michael Melzer and Falk Bahr and Denys Makarov and Wilfried Hofmann and Oliver G. Schmidt},
  title = {Ultra-Thin and Flexible Hall Effect Sensorics},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_66.pdf}
}
2014 Liu, J., Ding, G., Gao, B. and Zhang, B. Giant Magnetostrictive Material-Fiber Bragg Grating Magnetic Field Sensors Used in Magnetic Bearings Proceedings of ISMB14  
Abstract: A novel FBG-GMM sensor was proposed to measure magnetic flux density, in which the FBG was stuck perpendicular to the GMM’s principal magnetostriction orientation to make a thin-slice sensor. The FBG-GMM magnetic field sensor’s properties were tested on a U-shape electromagnet test setup, the measured data were consistent with the theoretical prediction and the sensor’ linear range is from 0.2T to 0.6T. The FBG-GMM magnetic field sensor was introduced to measure a radial magnetic bearing’s air-gap flux density. Static flux density measurement was performed through two FBG-GMM sensors and one temperature compensation FBG, and the measured data were consistent with the sensor properties obtained from the U-shape electromagnet test, which validate the FBG-GMM magnetic field sensor’s feasibility.
BibTeX:
@inproceedings{ISMB14_67,
  author = {Jiayi Liu and Guoping Ding and Bin Gao and Biyun Zhang},
  title = {Giant Magnetostrictive Material-Fiber Bragg Grating Magnetic Field Sensors Used in Magnetic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_67.pdf}
}
2014 Ni, T., Wang, X., Ding, Q. and Wu, G. Two Mathematical Models of Five-Phase High Speed Permanent Magnet bearingless Slice Motor Proceedings of ISMB14  
Abstract: Most bearingless motors run at a relatively low speed because of the high iron loss problem. Considering that a slotless structure is beneficial to high speed, this paper deduces two mathematical models based on this existent structure. The first model is for traditional control and the second one is for fault-tolerant control. In the process of derivation, the concept of superposition is introduced to calculate the flux density in the air gap. At last, finite element analysis is done to verify the model.
BibTeX:
@inproceedings{ISMB14_68,
  author = {Tuocheng Ni and Xiaolin Wang and Qiang Ding and Guyu Wu},
  title = {Two Mathematical Models of Five-Phase High Speed Permanent Magnet bearingless Slice Motor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_68.pdf}
}
2014 Siegl, G., Tzianetopoulou, T. and Denk, J. Simulation and Experimental Validation of a 9t AMB Rotor Landing in Rolling Element Back-Up Bearings Proceedings of ISMB14  
Abstract: Backup Bearings (BuB) must be designed to withstand the shock loads which occur during impacts with heavy and/or high-speed rotors. Both experimental testing and transient dynamic simulation are necessary for the study of BuB performance. This paper presents the transient dynamic simulation methodology developed within SIEMENS for the study of full-scale rotor landings in rolling element BuBs. The developed models were validated with a substantial landing program led and performed by SIEMENS, whose objective was to qualify the safe operation of hybrid rolling element BuBs for an industrial application utilizing an AMB-levitated 9t supercritical motor. The paper describes the BuB model, summarizes the simulation results and offers a comparison with experimental measurements from the aforementioned successful landing tests program.
BibTeX:
@inproceedings{ISMB14_69,
  author = {Guenther Siegl and Theodora Tzianetopoulou and Joachim Denk},
  title = {Simulation and Experimental Validation of a 9t AMB Rotor Landing in Rolling Element Back-Up Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_69.pdf}
}
2014 Stusak, M. Eddy Current Sensors for Magnetic Bearings of the Textile Spinning Machines Proceedings of ISMB14  
Abstract: The position sensors for magnetic bearings are very important parts of such a system. It is possible to say they are one of the most exacting part there because lot of conflicting demands are posed on them. This presentation describes the sensors for textile spinning machines which must have not only usual technical features but, in addition, they should fulfill the specific requirements of this industry, especially functionality in very dusty environment, resistance against foreign magnetic fields and last not least also potential for economical mass production without individual hardware setting and without selecting of specific components. Simply told, the prices at this market segment are forced down but the quality and reliability must be kept high.
BibTeX:
@inproceedings{ISMB14_7,
  author = {Miroslav Stusak},
  title = {Eddy Current Sensors for Magnetic Bearings of the Textile Spinning Machines},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_7.pdf}
}
2014 Lusty, C., Sahinkaya, N. and Keogh, P. A Novel Twin-Shaft Rotor with Active Magnetic Couplings for Vibration Control Proceedings of ISMB14  
Abstract: A novel rotor topology is proposed with the goal of reducing vibration in high speed rotor systems. Primarily, reduction in synchronous vibration at critical speeds is targeted. In essence, the novel topology consists of a hollow tube rotor coupled to a secondary non-rotating shaft through a number of actively managed magnetic couplings. An outline of the new topology is provided, along with a finite element analysis comparing the out-of-balance vibration response of the proposed rotor to a comparable simple rotor. Designs for a test rig based on this topology are presented, together with an outline of anticipated testing and potential future development of the idea.
BibTeX:
@inproceedings{ISMB14_70,
  author = {Chris Lusty and Necip Sahinkaya and Patrick Keogh},
  title = {A Novel Twin-Shaft Rotor with Active Magnetic Couplings for Vibration Control},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_70.pdf}
}
2014 Kamijo, Y., Ito, H. and Maruyama, Y. Structures and Characteristics of Magnetic Bearing with Zero Power Controlled Electromagnetic Suspension Proceedings of ISMB14  
Abstract: This paper proposes a new magnetic bearing in order to decrease rotor eccentricity and power consumption. The proposed bearing system consists of moving frames, suspensions, permanent magnets, electromagnets and Zero Power controller. The system enables to avoid rotor touchdowns. A clearance between a rotor and our proposed bearing may be increased compared to conventional electromagnetic bearings. The paper shows the experimental results to verify testing system.
BibTeX:
@inproceedings{ISMB14_71,
  author = {Yoshitake Kamijo and Hiroaki Ito and Yutaka Maruyama},
  title = {Structures and Characteristics of Magnetic Bearing with Zero Power Controlled Electromagnetic Suspension},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_71.pdf}
}
2014 Reischl, D., Dorninger, A., Fohler, A., Gerstmayr, J., Koppelstätter, W., Silber, S. and Weitzhofer, S. Coupled Mechanical and Electromagnetic Optimization of High Speed Rotors Proceedings of ISMB14  
Abstract: Optimizing mechatronic systems is of increasing importance, for example, to minimize the consumption of resources and energy during operation and production. The optimization objectives for rotordynamic systems are, for instance, critical resonances, durability and costs. In order to meet such objectives, good optimization algorithms as well as simulation tools for each physically relevant effect for the problem are required. In this paper, we present the coupling of the optimization software MagOpt and the mechatronic simulation tool HOTINT and an application of the system.
BibTeX:
@inproceedings{ISMB14_72,
  author = {Daniel Reischl and Alexander Dorninger and Armin Fohler and Johannes Gerstmayr and Werner Koppelstätter and Siegfried Silber and Simon Weitzhofer},
  title = {Coupled Mechanical and Electromagnetic Optimization of High Speed Rotors},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_72.pdf}
}
2014 Detoni, J.G., Impinna, F., Amati, N., Tonoli, A., Piccolo, M.P. and Genta, G. Stability of a 4 degree of freedom rotor on electrodynamic passive magnetic bearings Proceedings of ISMB14  
Abstract: Electrodynamic bearings exploit repulsive forces due to eddy currents to produce positive stiffness by passive means without violating the Earnshaw stability criterion. This remarkable characteristic makes this type of bearing a suitable alternative to active magnetic bearings in fields such as kinetic energy storage flywheels, turbo pumps, high speed compressors, among others. However, the suspension can become unstable due to rotating damping. To obtain deeper understanding of this instability phenomenon this paper presents the analysis of stability of a four degree of freedom (4dof) rotor supported by electrodynamic bearings. The 4dof rotor model is coupled to the dynamic model of the eddy current forces generated by the electrodynamic bearing and the stability of the complete system is analyzed. This model is used to study the stability of both cylindrical and conical whirling motion of the rotor. In addition to the well known cylindrical whirl instability the possible occurrence of conical instability is demonstrated. Finally the effects of two stabilization strategies are analyzed.
BibTeX:
@inproceedings{ISMB14_73,
  author = {Joaquim Girardello Detoni and Fabrizio Impinna and Nicola Amati and Andrea Tonoli and Maria Pina Piccolo and Giancarlo Genta},
  title = {Stability of a 4 degree of freedom rotor on electrodynamic passive magnetic bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_73.pdf}
}
2014 Ooshima, M. and Gomi, Y. Characteristics of Torque and Suspension Force in a d-q Axis Current Control Bearingless Motor Proceedings of ISMB14  
Abstract: This paper presents the characteristic of torque and suspension force in a d-q axis current control bearingless motor. It is derived based on Finite Element (FE) analysis using a simulation software, and furthermore compared with the computed results of the conventional bearingless motors, which two kinds of windings for motor drive and magnetic suspension are wound in a stator core. Three types of the conventional bearingless motor with n-pole motor winding and (n +- 2)-pole suspension winding are taken up and their computed results of the torque and suspension force are discussed in detail. As a result, the superiority of the proposed d-q axis current control bearingless motor is found.
BibTeX:
@inproceedings{ISMB14_74,
  author = {Masahide Ooshima and Yuto Gomi},
  title = {Characteristics of Torque and Suspension Force in a d-q Axis Current Control Bearingless Motor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_74.pdf}
}
2014 Mikota, G., Proell, A. and Silber, S. Experimental Modal Analysis of a Gyroscopic Rotor in Active Magnetic Bearings Proceedings of ISMB14  
Abstract: For a gyroscopic rotor in active magnetic bearings, the rigid body natural frequencies and mode shapes are investigated. An impulsive excitation force is generated by two rectangular pulses in the current control reference signal. With vibration measurements available in two perpendicular directions for each bearing, experimental modal analyses are performed at rotational speeds up to 100000 rpm. Identification results demonstrate the gyroscopic split of natural frequencies.
BibTeX:
@inproceedings{ISMB14_75,
  author = {Gudrun Mikota and Andreas Proell and Siegfried Silber},
  title = {Experimental Modal Analysis of a Gyroscopic Rotor in Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_75.pdf}
}
2014 Denk, J., Koehler, B.-U., Siegl, G. and Siebke, P. Landing Tests with a 6300rpm, 9t AMB Rotor in Rolling Element Back-Up Bearings Proceedings of ISMB14  
Abstract: This article describes a systematic approach to qualify backup bearings for very large rotors levitated by active magnetic bearings (AMB). The approach comprises dynamic simulations of the landing events prior to the testing with good prediction quality as part of the safety concept. The approach was applied for the backup bearing qualification of a 9t rotor with a rotational speed up to 6420rpm. The results of the landing tests are shown and compared with the simulation results.
BibTeX:
@inproceedings{ISMB14_76,
  author = {Joachim Denk and Bert-Uwe Koehler and Guenther Siegl and Peter Siebke},
  title = {Landing Tests with a 6300rpm, 9t AMB Rotor in Rolling Element Back-Up Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_76.pdf}
}
2014 Lopes, J.S.B., dos Santos, L.P., de Paiva, J.A., Victor, V.F., Maitelli, A.L. and Salazar, A.O. Rotor Flux Observer Based Neuro-Fuzzy Techniques to Speed Vector Control of a Bearingless AC Motor Proceedings of ISMB14  
Abstract: This study presents the problem of rotor flux orientation control of bearingless induction motor. The key of this solution is the estimation of rotor flux. This work applied an inference system using fuzzy logic and the neural networks with the MATLAB(R). The Adaptive Neuro-Fuzzy Inference System (ANFIS) is based in an input-output model. ANFIS is used to tune the membership functions in fuzzy system and utilize the backpropagation learning algorithm. This system was applied to estimate the rotor flux and the magnetization current of the purpose of identifying bearingless induction motor angular speed. The hybrid estimator aims at compensating possible parametric variations of the machine caused by agents such as temperature or nucleus saturation. The simulated results showed good performance. The results demonstrated the feasibility of the proposed technique. The ANFIS estimator proposed will be embedded in the DSP TMS 3208F28335 in future works.
BibTeX:
@inproceedings{ISMB14_77,
  author = {Jose Soares Batista Lopes and Luciano Pereira dos Santos and Jose Alvaro de Paiva and Valci F. Victor and Andre L. Maitelli and Andres O. Salazar},
  title = {Rotor Flux Observer Based Neuro-Fuzzy Techniques to Speed Vector Control of a Bearingless AC Motor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_77.pdf}
}
2014 Xu, Z. and Ahn, J.-W. Eccentricity Analysis and Efficiency Estimation of 12/14 Hybrid Stator Pole Bearingless SRM Proceedings of ISMB14  
Abstract: The radial force to suspend the rotor in a constant air-gap for bearingless switched reluctance motor (BLSRM) is dependent on air-gap and force current. Due to the non-linear characteristic of inductance, the radial force is much affected by the rotor eccentricity. In order to keep constant air-gap of rotor, the nonlinear characteristics of eccentricity should be analyzed. Further, the auxiliary bearing is always used to restrict the maximum eccentricity of the rotor in industry. In this paper, the rotor eccentricity effect in the proposed 12/14 BLSRM is analyzed. Meanwhile, the efficiency of the 8/10 and proposed BLSRMs is estimated. The analysis results further verify the validity of the proposed BLSRM.
BibTeX:
@inproceedings{ISMB14_78,
  author = {Zhenyao Xu and Jin-Woo Ahn},
  title = {Eccentricity Analysis and Efficiency Estimation of 12/14 Hybrid Stator Pole Bearingless SRM},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_78.pdf}
}
2014 Shinshi, T., Hijikata, W., Mamiya, T. and Takatani, S. Development of Extracorporeal Maglev Blood Pumps Proceedings of ISMB14  
Abstract: In centrifugal blood pumps, contactless support of the impeller and a sufficient fluid gap in the pump head have been identified as features that have the potential to keep blood damage to a minimum and enhance the durability of the blood pump. We have developed three types of cost-effective magnetic bearings and contactless torque transmission mechanisms for disposable centrifugal blood pumps which can be used for extracorporeal circulation. In this paper, we introduce prototype maglev centrifugal blood pumps that utilize these mechanisms and we present both the experimental results and the results of simulations carried out on them.
BibTeX:
@inproceedings{ISMB14_79,
  author = {Tadahiko Shinshi and Wataru Hijikata and Taichi Mamiya and Setsuo Takatani},
  title = {Development of Extracorporeal Maglev Blood Pumps},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_79.pdf}
}
2014 Okada, Y., Suzuki, H., Matsuda, K.-I., Kondo, R. and Enokizono, M. Development of Highly Efficient Magnetic Bearing and Application to Ultra-Low Temperature Fluid Pump Proceedings of ISMB14  
Abstract: Highly efficient hybrid type magnetic bearing is proposed in this paper. It is intended to apply the proposed magnetic bearing to ultra low temperature fluid pump. Traditional low temperature pump is supported by a ceramic ball bearing which is damaged by the low temperature liquid. Non-contact support is highly requested. However, the standard electro-magnetic bearing consumes high electric power causing heat to the liquid. This paper proposes highly efficient hybrid type radial magnetic bearing which can operate with very low power consumption. Also the pump is canned by the FRP pipe which has thick wall to separate the stator from the liquid. The designed magnetic bearing has 3 [mm] wide air gap with high force factor.
BibTeX:
@inproceedings{ISMB14_8,
  author = {Yohji Okada and Hironari Suzuki and Ken-Ichi Matsuda and Ryou Kondo and Masato Enokizono},
  title = {Development of Highly Efficient Magnetic Bearing and Application to Ultra-Low Temperature Fluid Pump},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_8.pdf}
}
2014 Osa, M., Masuzawa, T., Omori, N. and Tatsumi, E. Radial Position Active Control of Double Stator Axial Gap Self-Bearing Motor for Paediatric VAD Proceedings of ISMB14  
Abstract: A novel axial gap double stator self-bearing motor which can control five-degrees of freedom (5-DOF) of rotor postures have been developed for paediatric ventricular assist device (VAD). The motor has a top stator, a bottom stator and a levitated rotor driven as a synchronous permanent magnet motor. The rotor is axially suspended between the stators which have an identical structure. A double stator mechanism enhances a higher torque production and realizes radial position active control. This paper proposes a concept of radial position active control and magnetic suspension ability of developed selfbearing motor. The rotor is successfully levitated and rotated up to 6400 rpm without any physical contact with 5-DOF active control in air. The radial oscillation amplitudes are actively suppressed with the proposed radial position control concept. The developed 5-DOF controlled self-bearing motor which is suitably miniature as an actuator for paediatric VAD indicates sufficient capability of the magnetic levitation and non-contact rotation.
BibTeX:
@inproceedings{ISMB14_80,
  author = {Masahiro Osa and Toru Masuzawa and Naoki Omori and Eisuke Tatsumi},
  title = {Radial Position Active Control of Double Stator Axial Gap Self-Bearing Motor for Paediatric VAD},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_80.pdf}
}
2014 dos Santos, L.P., Lopes, J., Victor, V., Maitelli, A. and Salazar, A. Robust Speed Controller of a Bearingless AC Motor Type Divided Winding, Based on a Conventional Squirrel Cage Induction Motor Proceedings of ISMB14  
Abstract: This paper shows a new approach to control the speed of rotor field oriented for a bearingless AC Motor type divided winding for a conventional squirrel cage Induction Motor of 3.75 kW, 380V, 4-poles, 60Hz, 1.04 Nm. To implement the control strategies, was chosen the rotor flux referential (R-FOC). This referential is based on decomposition of the stator current into two components done in a decoupled manner: flux controlled by stator direct-axis current and torque controlled by quadrature-axis current. To implement the control algorithm, was chosen the rotor flux referential, which is being estimated through the stator winding currents and the rotor speed. The vectorial speed controller operates in synchronism with the radial positioning controller, but these controllers should work with low mutual influence.
BibTeX:
@inproceedings{ISMB14_81,
  author = {Luciano Pereira dos Santos and Jose Lopes and Valci Victor and Andre Maitelli and Andres Salazar},
  title = {Robust Speed Controller of a Bearingless AC Motor Type Divided Winding, Based on a Conventional Squirrel Cage Induction Motor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_81.pdf}
}
2014 He, Y., Nonami, K. and Shimizu, F. A Method of Simple Adaptive Control for MIMO Nonlinear AMB-Flywheel Levitation System Proceedings of ISMB14  
Abstract: In this paper, AMB-flywheel is desirable to minimize the energy required for its stabilization control. We propose a design method for performing SAC control for a MIMO AMB-flywheel system with five degrees of freedom; The SAC controller was proposed for application to an AMB-flywheel system and control performance was improved by combining SAC with PID controller. The PID based SAC controller is evaluated via experiments. We present the analysis results of the influence of external disturbances from the EV driving on the road and high-speed rotation experimental results about the AMB-flywheel system. The results demonstrate that the SAC controller is feasible and effective.
BibTeX:
@inproceedings{ISMB14_82,
  author = {Yong He and Kenzo Nonami and Fumiya Shimizu},
  title = {A Method of Simple Adaptive Control for MIMO Nonlinear AMB-Flywheel Levitation System},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_82.pdf}
}
2014 Kluyskens, V. and Dehez, B. Optimization of a New Radial Electrodynamic Damper Proceedings of ISMB14  
Abstract: The study of electrodynamic dampers is an important point when working with electrodynamic bearings. These dampers may also be used in combination with reluctant passive magnetic bearings. This paper proposes a new design of a robust and inherently stable radial electrodynamic damper with a homopolar axial magnetic flux. An optimization, based on finite element models, of this new bearing topology is made. For this to be possible, a 2-D representation of the damper is developed equivalent to the 3-D damper. The results of the optimizations are presented and a discussion of the influence of some of the parameters is done.
BibTeX:
@inproceedings{ISMB14_83,
  author = {Virginie Kluyskens and Bruno Dehez},
  title = {Optimization of a New Radial Electrodynamic Damper},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_83.pdf}
}
2014 Shimizu, F. and Nonami, K. Benchmark and Verification of Control Algorithm for Flywheel with Active Magnetic Bearing on Electric Vehicle and Proposal of New SAC Algorithm (ε1 modification and bias variable Γp approach) Proceedings of ISMB14  
Abstract: This paper presents the requirements which a good rotor controller of flywheel energy storage system (FESS) with Active Magnetic Bearing (AMB) on Electric Vehicle (EV) should satisfy. AMB-FESS is used for energy regeneration. The dynamics of the flywheel rotor on EV is very complex and to compare various features a benchmark is necessary. Controllers are evaluated according to certain criteria as used by many motor companies. Controllers are selected to satisfy the design requirements prescribed by many motor companies. Thus the robust adaptive controllers were chosen and benchmarked using simulations and experiments. The investigation revealed that a controller with high rigidity gain and a reference model can not only suppress disturbance effects but also lower power consumption. Therefore Simple Adaptive Control with epsilon1 modification and bias variable gamma P approach is proposed. The utility of the new controller experimentally was proven.
BibTeX:
@inproceedings{ISMB14_84,
  author = {Fumiya Shimizu and Kenzo Nonami},
  title = {Benchmark and Verification of Control Algorithm for Flywheel with Active Magnetic Bearing on Electric Vehicle and Proposal of New SAC Algorithm (ε1 modification and bias variable Γp approach)},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_84.pdf}
}
2014 Quurck, L., Schaede, H., Richter, M. and Rinderknecht, S. High Speed Backup Bearings for Outer-Rotor-Type Flywheels - Proposed Testrig Design Proceedings of ISMB14  
Abstract: Magnetic levitated rotors for high speed applications need backup bearing (BB) for safe spin down or relevitation after magnetic bearing failure or overload situations. Especially in flywheel energy storage systems long spin down times due to the high kinetic energy content and the vacuum environment complicate the use of conventional bearings as BBs. Depending on the geometric dimension, the rotational speed of the rotor and associated rotordynamic effects today’s available bearings (usually rolling element bearings) cannot fulfill their task with the desired lifetime. This paper shows mechanical and thermal problems as well as approaches to mitigate them. For a built and tested Outer-Rotor-Type flywheel its BB system is discussed. For an increase of the surface velocity limit and the extension of the BB lifetime several design improvements are suggested. Properties of a test rig and its special rotor design for BB testing are described and proposed for further experimental investigation. A design of the test-BB is proposed and the data acquisition as well as the dynamic behavior of the rotor is described.
BibTeX:
@inproceedings{ISMB14_85,
  author = {Lukas Quurck and Hendrik Schaede and Michael Richter and Stephan Rinderknecht},
  title = {High Speed Backup Bearings for Outer-Rotor-Type Flywheels - Proposed Testrig Design},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_85.pdf}
}
2014 Cole, M., Jimenez, S. and Keogh, P. Feedback Control of a Magnetic Bearing Using Fusion of Rotor Acceleration and Position Measurements Proceedings of ISMB14  
Abstract: This paper considers controlling a magnetic bearing using combined feedback of rotor acceleration and position measurements. A controller design based on sensor fusion via complementary filtering is described. The control method can maintain stability while allowing the cross-over frequency for the acceleration and position feedback loops to be set arbitrarily. In this way, position measurements can be utilized primarily for disturbance cancellation over a low frequency band while acceleration feedback maintains bearing stability and disturbance rejection over a higher frequency band. The approach has the advantage that it gives enhanced robustness to poor quality position measurements. For flexible rotors, stabilization with large axial separation of position sensors and bearing locations can be easily achieved by utilizing collocated rotor-embedded accelerometers. The approach also offers improved robustness to measurement noise, position sensor run-out error and other forms of physical contamination or damage. Through analysis and simulation, important physical effects on vibration control performance are identified and further considered within the design methodology.
BibTeX:
@inproceedings{ISMB14_86,
  author = {Matthew Cole and Samuel Jimenez and Patrick Keogh},
  title = {Feedback Control of a Magnetic Bearing Using Fusion of Rotor Acceleration and Position Measurements},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_86.pdf}
}
2014 Onuma, H. and Masuzawa, T. Evaluation of Magnetic Suspension Characteristics and Levitation Performance of a Centrifugal Blood Pump Using Radial Type Self-Bearing Motor Proceedings of ISMB14  
Abstract: Magnetic levitation technology is applied for durability enhancement of artificial hearts. A centrifugal blood pump using a self-bearing motor was previously developed for use as an implantable artificial heart. Rotors of three types which are different of magnetic suspension characteristics were fabricated. The magnetic suspension characteristics, the levitation and the pump performances of the Maglev pump were examined. If the negative spring force in the radial direction was weak, the restoring force in the axial direction and the restoring torque of the inclination were not always weak. It is possible to improve the motor performance by increasing the flux density of permanent magnet, even if the air gap is increased. It revealed that the levitation performance does not influence the pump performance. And then, it is possible to improve the levitation performance by reducing the negative spring force and improving the passive stability ability.
BibTeX:
@inproceedings{ISMB14_87,
  author = {Hiroyuki Onuma and Toru Masuzawa},
  title = {Evaluation of Magnetic Suspension Characteristics and Levitation Performance of a Centrifugal Blood Pump Using Radial Type Self-Bearing Motor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_87.pdf}
}
2014 Fleischer, E. and Hofmann, W. Linear and Nonlinear Control of a Three Pole Combined Active Magnetic Bearing - a Comparison Proceedings of ISMB14  
Abstract: This paper analyses a linear and a nonlinear control strategy for a 5-axis magnetic suspension system built with two three pole combined bearings. In these soft magnetic composites (SMC) are used as iron core material to carry the required threedimensional flux distribution. While the linear approach is designed around the CLARKE-Transformation to stabilize the bearing, the nonlinear one is based on feedback linearization to achieve a stable system even in the case of minimal bias flux. The paper outlines the control strategies and the controller design. Both schemes are compared regarding tracking behavior, decoupling performance and stability margin based on experimental results in the time and frequency domain.
BibTeX:
@inproceedings{ISMB14_88,
  author = {Erik Fleischer and Wilfried Hofmann},
  title = {Linear and Nonlinear Control of a Three Pole Combined Active Magnetic Bearing - a Comparison},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_88.pdf}
}
2014 Wang, X., Liu, Q., Hu, Y., Chen, H. and Geng, Q. Research on Redundancy of Weak Coupling Radial Magnetic Bearing Proceedings of ISMB14  
Abstract: The weak coupling radial magnetic bearing structure and force balance compensation has been proposed in this paper. The force balance compensation of weak coupling radial magnetic bearing is simulated and comparison with bias current linearization. The research shows the force balance compensation can provide bigger electromagnetic force, the process of solving compensation matrix is simple, and the compensation current is more uniform. Meanwhile, The experimental results verify the feasibility of weak coupling radial magnetic bearing with redundant structure and force balance compensation.
BibTeX:
@inproceedings{ISMB14_89,
  author = {Xiaoguang Wang and Qian Liu and Yefa Hu and Haohui Chen and Qingling Geng},
  title = {Research on Redundancy of Weak Coupling Radial Magnetic Bearing},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_89.pdf}
}
2014 Wang, J. and Binder, A. Position Estimation for Self-Sensing Magnetic Bearings Based on Double Detection of Current Slopes Proceedings of ISMB14  
Abstract: This paper introduces a new approach to estimate the rotor position of self-sensing magnetic bearings, which works on detecting the current slopes during both positive and negative voltage switching of PWM amplifiers. The position is estimated using the current slopes straightforward. The consideration of double current slopes shows advantages concerning the reduction of the influences of the coil resistance and the induced voltage due to the rotor movement. The current slope is calculated by multiple current sampling, therefore, no additional hardware is needed for the current slope measurement. Experimental results verified the proposed approach.
BibTeX:
@inproceedings{ISMB14_9,
  author = {Jinou Wang and Andreas Binder},
  title = {Position Estimation for Self-Sensing Magnetic Bearings Based on Double Detection of Current Slopes},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_9.pdf}
}
2014 Richter, M., Schaede, H. and Rinderknecht, S. Investigations on the "Direct Digital Inductance Estimation" - Concept for Self-Sensing AMBs Under Influence of Eddy Currents Proceedings of ISMB14  
Abstract: This article states the challenges connected with eddy-currents by use of the direct digital inductance estimation (DDIE) concept for self-sensing active magnetic bearings. Starting with a short introduction to the estimation algorithm, the negative influences of eddy currents on the position estimation are described step by step. Such influences are an increasing position noise as well as an interval and duty cycle dependent position error. The article closes with an outlook on additional investigations to further separate, quantify, and reduce the associated position error in order to extend the performance of the DDIE-concept.
BibTeX:
@inproceedings{ISMB14_90,
  author = {Michael Richter and Hendrik Schaede and Stephan Rinderknecht},
  title = {Investigations on the "Direct Digital Inductance Estimation" - Concept for Self-Sensing AMBs Under Influence of Eddy Currents},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_90.pdf}
}
2014 Lundin, J., Kamf, T., Abrahamsson, J., de Santiago, J., Hedlund, M. and Bernhoff, H. High Speed Flywheels for Vehicular Applications Proceedings of ISMB14  
Abstract: This article analyzes two business cases using flywheels in vehicles. Firstly, a diesel based car ferry, in Gothenburg, performing 102 5 minute long journeys per day. Secondly, a diesel based city bus. A theoretical analysis of the benefits, technical and economical, of electrifying these vehicles using flywheels is performed. As basis for the analysis is a constructed high-speed flywheel, designed to store up to 870Wh at a rotational speed of 30 000 rpm. The rotor of the flywheel is constructed from a permanent magnet machine surrounded by a shell of composite material. The flywheel is optimized for low loss as well as low cost. The economical analysis of the two business cases show great potential for cost reduction by either utilizing a flywheel as temporary energy storage for capturing regenerative braking energy or replacing the diesel generator completely as main energy storage. The main material cost of the constructed flywheel pertains to the position sensors and the permanent magnet material used in the magnetic bearing.
BibTeX:
@inproceedings{ISMB14_91,
  author = {Johan Lundin and Tobias Kamf and Johan Abrahamsson and Juan de Santiago and Magnus Hedlund and Hans Bernhoff},
  title = {High Speed Flywheels for Vehicular Applications},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_91.pdf}
}
2014 Mach, F., Karban, P. and Dolezel, I. Design of Novel Bearing-Less Electromagnetic Actuator in Valve Operation Proceedings of ISMB14  
Abstract: A new bistable electromagnetic actuator is designed and modelled. The actuator with a magnetically moved plunger represents the main part of a valve intended for control of flow of electrically non-conductive liquids. Presented is the basic concept of the valve together with its mathematical model that is solved numerically by the code Agros2D developed by the authors. The aim of the work is to verify the functionality of the device and find its basic operation characteristics.
BibTeX:
@inproceedings{ISMB14_92,
  author = {Frantisek Mach and Pavel Karban and Ivo Dolezel},
  title = {Design of Novel Bearing-Less Electromagnetic Actuator in Valve Operation},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_92.pdf}
}
2014 Bonfitto, A., Cabrera, L.D.S. and Tonoli, A. Active Magnetic Bearings with Position and Flux Observer Proceedings of ISMB14  
Abstract: Standard Active Magnetic Bearings are controlled using a current reference and the measured or observed current as state variable in the state space controller. Nevertheless since this approach selects the current as the state expressing the behavior of the magnetic bearing, several disadvantages occur. Indeed it is well known that this method leads to an inherent nonlinear relation between the generated force, the current and the air gap. This paper presents the modeling approach, the control design and the experimental validation of a strategy based on the combined observation of position and flux. The technique is designed and tested on a one-degree of freedom mechanical oscillator actuated by a couple of opposite electromagnets.
BibTeX:
@inproceedings{ISMB14_93,
  author = {Angelo Bonfitto and Lester Daniel Suarez Cabrera and Andrea Tonoli},
  title = {Active Magnetic Bearings with Position and Flux Observer},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_93.pdf}
}
2014 Schaede, H., Richter, M., Quurck, L. and Rinderknecht, S. Losses in an Outer-Rotor-Type Kinetic-Energy-Storage-System in Active Magnetic Bearings Proceedings of ISMB14  
Abstract: This paper starts with a general description of the losses and the classification of the loss components in kinetic energy storage systems. Based on the design of an outer-rotor-type kinetic energy storage system an analytical loss model is presented. It considers the conversion losses and the drag losses of the electric drive, the drag losses of the homopolar active magnetic bearings and the gas friction losses, as well as the constant losses such as caused by the bias magnetization of the active magnetic bearings. In detail a new approach for the analytical calculation of the drag losses of the homopolar active magnetic bearings is presented, taking the eddy current and hysteresis losses as well as the penetration depth of the magnetic field into the rotor in account. The paper ends with the presentation of a developed measurement method for the experimental determination of the loss map of kinetic energy storage systems. It enables for the isolation of the drag loss components of the drive system, the magnetic bearings and the gas friction losses.
BibTeX:
@inproceedings{ISMB14_94,
  author = {Hendrik Schaede and Michael Richter and Lukas Quurck and Stephan Rinderknecht},
  title = {Losses in an Outer-Rotor-Type Kinetic-Energy-Storage-System in Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_94.pdf}
}
2014 Whitlow, Z., Fittro, R. and Knospe, C. Segmented Magnetic Thrust Bearings: Analytic Models and Predictions of Significant Improvement in Dynamic Performance Proceedings of ISMB14  
Abstract: Non-laminated magnetic thrust bearings typically exhibit reduced dynamic performance due to eddy currents compared to laminated bearings. Segmented stators have been introduced to increase actuator performance by disrupting eddy current paths in the same manner as laminations in radial magnetic bearings. However, due to manufacturing limitations thrust bearing stators cannot be easily segmented to the extent that they would be considered fully laminated. Therefore, eddy currents continue to affect the dynamic performance significantly. Since analytic models of segmented stators do not presently exist the bearing design process requires the use of finite element analysis (FEA) and experimentation. Here we show, using finite element analysis, that a small number of cuts dramatically improves bandwidth of non-laminated magnetic actuators, validating the segmented design strategy. In addition, existing analytic models of non-laminated magnetic bearings are adapted to a segmented geometry and validated via FEA. Close agreement shows that the analytic model, rather than time consuming FEA, may be used in the design process.
BibTeX:
@inproceedings{ISMB14_95,
  author = {Zackary Whitlow and Roger Fittro and Carl Knospe},
  title = {Segmented Magnetic Thrust Bearings: Analytic Models and Predictions of Significant Improvement in Dynamic Performance},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_95.pdf}
}
2014 Li, P., Sahinkaya, N. and Keogh, P. Active Touchdown Bearing Control for Recovery of Contact-Free Rotor Levitation in AMB Systems Proceedings of ISMB14  
Abstract: Control strategies for rotor displacements and transmitted forces in active magnetic bearing (AMB) systems are generally well-developed when the rotor is in contact-free levitation. In such a condition, the rotor/AMB system, the plant to be controlled, is well-defined to use for controller design. However, transient overload conditions or large scale disturbances may cause the rotor to make contact with one or more touchdown bearings (TDBs). The ensuing dynamic response is an effective change to the contact-free plant, which may cause an AMB controller to apply inappropriate forces, causing persistent contact, or even inducing system instability. It is therefore beneficial to restore contact-free levitation as quickly as possible in order that normal operation may resume. This would minimise outage time and also minimise high levels of potentially damaging contact that may be experienced by the TDBs. In this paper, the use of an active TDB is considered for the restoration of contact-free levitation. The contact problem is demonstrated in simulation and also through appropriate control applied in an experimental system. In this system, TDB motion is activated by piezoelectric stack actuators.
BibTeX:
@inproceedings{ISMB14_96,
  author = {Peichao Li and Necip Sahinkaya and Patrick Keogh},
  title = {Active Touchdown Bearing Control for Recovery of Contact-Free Rotor Levitation in AMB Systems},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_96.pdf}
}
2014 Cui, Q., Sandtner, J. and Bleuler, H. Whirl Imposer --- Proposal for a Novel Passive Magnetic Rotor Bearing System Proceedings of ISMB14  
Abstract: Passive magnetic bearing systems are enticing in applications where low stiffness is acceptable, but where cost, life-time, power consumption and reliability are critical. This article investigates a new proposal for stabilization of permanent magnet (i.e. passive) bearing systems based on rotor precession. There will be a minimal and a maximal rotational speed for stable contact-free levitation. The feasibility of this new stabilization scheme is investigated with the help of realistic numerical data, a demonstration system is currently in planning.
BibTeX:
@inproceedings{ISMB14_97,
  author = {Qingwen Cui and Jan Sandtner and Hannes Bleuler},
  title = {Whirl Imposer --- Proposal for a Novel Passive Magnetic Rotor Bearing System},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_97.pdf}
}
2014 Collins, T., Masala, A., Shultz, R. and Guo, Z. Numerical and Experimental Results of Auxiliary Bearings Testing on a High Speed Test Rig Proceedings of ISMB14  
Abstract: A test stand including a rotor and active magnetic bearing system, located at Waukesha Magnetic Bearing premises was utilized in 2013 to validate a new auxiliary bearing design. This paper provides an overview of the preparatory activities and an insight on the numerical and experimental results obtained during the testing campaign.
BibTeX:
@inproceedings{ISMB14_98,
  author = {Tim Collins and Andrea Masala and Richard Shultz and Zenglin Guo},
  title = {Numerical and Experimental Results of Auxiliary Bearings Testing on a High Speed Test Rig},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_98.pdf}
}
2014 Recheis, M. Increasing Bearing Life-Time of Mobile Flywheels by Using Bearing-Less Drive Methods Proceedings of ISMB14  
Abstract: Fully electric and hybrid electric power trains enable reuse of braking energy. This decreases the amount of lost energy dramatically, especially for discontinuous operation. Good examples are urban traffic, public transportation or delivery services. Mobile flywheels provide an excellent potential for the emerging market of electrified power trains, but they are currently only used in a few applications such as motor sports (Formula 1, Le Mans, GT3 car racing). To enable a wider use in personal or public transportation, the life-span of the flywheel’s bearings have to be increased significantly. This paper presents an alternative approach to extend the life-span of the rolling element bearings by using bearing-less drive methods.
BibTeX:
@inproceedings{ISMB14_99,
  author = {Manes Recheis},
  title = {Increasing Bearing Life-Time of Mobile Flywheels by Using Bearing-Less Drive Methods},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_99.pdf}
}
2014 Mushi, S. and Allaire, P. Control of a Flexible Rotor AMB Compressor Test Rig with Aerodynamic Cross Coupling Proceedings of ISMB14  
Abstract: Many industrial companies are adopting magnetic bearings for high speed compressors at this time. A flexible rotor test rig of approximately 1.2 m in length was developed with four active magnetic radial bearings. It was employed to evaluate the control of destabilizing aerodynamic cross coupling stiffness Q in the center of the machine. The two end AMBs were used for support and one center AMB used to apply the cross coupled stiffness corresponding to a typical location of gas seal cross coupled stiffness sources. The fourth AMB was employed as a system exciter. Unfortunately for the compressor manufacturer and the end user, often the magnitude of the cross coupled stiffness changes with various compressor operating conditions. The test rig shaft operated up to about 18,000 rpm, through the first bending critical speed which was at approximately 14,000 rpm. m-synthesis control was used to achieve highly effective control and low vibration response with the selection of an averaged value of cross coupled stiffness Q and a set of useful system uncertainty weighting functions when the controller does not have exact advance notice of the cross coupling stiffness amplitude. Details of the application of the mu synthesis controller implementation are presented. A physical approach to modeling the Q uncertainty involved selecting an expected nominal value of the real part of the first rotor system eigenvalue for the rotor first bending mode with an expected range of uncertainly above and below that value. Then suitable weighting functions were developed for the mu synthesis controller design. The measured sensitivity function was below 3 at 7,000 rpm when the rotor was subjected to high cross coupled stiffness at the center.
BibTeX:
@inproceedings{ISMB14_key01,
  author = {Simon Mushi and Paul Allaire},
  title = {Control of a Flexible Rotor AMB Compressor Test Rig with Aerodynamic Cross Coupling},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_key01.pdf}
}
2014 Bleuler, H. Overview on Various Types of AMBs & their Respective Potential for Applications Proceedings of ISMB14  
Abstract: Many different types of magnetic bearings are known since a long time: “Active” and “passive”, “electrodynamic”, “electromagnetic”, “hybrid” etc. Certain types have found many applications and others none. A recent successful realization of a complex system (a momentum reaction sphere) based on a Lorentz-force type of bearing will be presented in more detail and the potential of as yet unexploited types of magnetic bearings will be briefly discussed.
BibTeX:
@inproceedings{ISMB14_key02,
  author = {Hannes Bleuler},
  title = {Overview on Various Types of AMBs & their Respective Potential for Applications},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_key02.pdf}
}
2014 Kroll, M. Electrical drive systems with active magnetic bearings in industrial applications - possibilities and challenges Proceedings of ISMB14  
Abstract: This article describes the use of active magnetic bearings in an electrical drive system and how performance, reliability and availability can be increased significantly based on an application example. It is important to know about the strong interaction between the different system components to get the best technical results, as well as considering production related aspects.
BibTeX:
@inproceedings{ISMB14_key03,
  author = {Matthias Kroll},
  title = {Electrical drive systems with active magnetic bearings in industrial applications - possibilities and challenges},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_key03.pdf}
}
2014 Sloupensky, J. Magnetic Bearings: Application to High Speed Textile Processing Proceedings of ISMB14  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB14_key04,
  author = {Jiri Sloupensky},
  title = {Magnetic Bearings: Application to High Speed Textile Processing},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_key04.pdf}
}
2014 Swann, M. Industrialisation Trends for Active Magnetic Bearings in the Turbomachinery Industry Proceedings of ISMB14  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB14_key05,
  author = {Mike Swann},
  title = {Industrialisation Trends for Active Magnetic Bearings in the Turbomachinery Industry},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_key05.pdf}
}
2013 Bulic, N., Dirnberger, P. and Silber, S. New Sensor Design for Rotor Displacement Measurement Based on the Coupled Oscillators Theory Proceedings of BWMB2013  
Abstract: Measurement of rotor position in bearingless motors and bearingless systems is of essence for proper operation. Insufficient resolution, sensor insensitivity and low sampling rate in measurement process leads unstable levitation and in worst case to the collision of rotor and stator which could end with motor destruction. Paper presents new concept for rotor position measurement based on Eddy current principle and Coupled oscillators theory in order to get accurate rotor position information. New concept is based on injection locking phenomena between coupled oscillators. Opposite pair of sensing oscillators are electrically coupled via resistor. In injection locking conditions phase shift between coupled oscillators is proportional to rotor movement. Phase shift was measured with Time to Digital Converter (TDC) and information is passed to Digital Signal Processor DSP over SPI communication link. DSP calculates the rotor position which is passed to power electronic circuit for rotor position control.
BibTeX:
@inproceedings{BWMB2013_1,
  author = {Neven Bulic and Peter Dirnberger and Sigfried Silber},
  title = {New Sensor Design for Rotor Displacement Measurement Based on the Coupled Oscillators Theory},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_1.pdf}
}
2013 Filatov, A.V. and Hawkins, L.A. Novel Combination Radial/Axial Homopolar Active Magnetic Bearing Proceedings of BWMB2013  
Abstract: A novel combination radial/axial homopolar permanent-magnet-biased electromagnetic actuator for application in active magnetic bearings is proposed. The design combines the best features of the earlier solutions: shorter axial length, lower part count, lower aerodynamic drag, lower negative stiffness and lower cost typical for combination bearings along with better axial bandwidth typically demonstrated in arrangements of separate radial and axial bearings. Furthermore, for most machines, the actuator topology leads to rotor construction that results in a higher first bending mode frequency than previous designs.
BibTeX:
@inproceedings{BWMB2013_12,
  author = {Alexei V. Filatov and Lawrence A. Hawkins},
  title = {Novel Combination Radial/Axial Homopolar Active Magnetic Bearing},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_12.pdf}
}
2013 de Paiva, J.A., Salazar, A.O. and Maitelli, A.L. Review of Control Strategies and Model Estimation Techniques applied to Bearingless Induction Machine with Divided Winding Proceedings of BWMB2013  
Abstract: The bearingless induction machines exhibit significant nonlinearities, creating the need for implementation of control systems that combine the classic control techniques with modern model observers. Aiming to contribute to the development of new systems, this paper presents an overview of the main control and estimation strategies implemented in laboratory using the induction bearingless machines with divided winding, highlighting the advances and difficulties arising from these type of systems.
BibTeX:
@inproceedings{BWMB2013_14,
  author = {Jose A. de Paiva and Andres O. Salazar and Andre L. Maitelli},
  title = {Review of Control Strategies and Model Estimation Techniques applied to Bearingless Induction Machine with Divided Winding},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_14.pdf}
}
2013 Rudolph, J., Werner, R. and Maximow, I. Measurement of the Rotor Position of an Active Magnetic Bearing Using Interpolar Stray Flux Proceedings of BWMB2013  
Abstract: The very most active magnetic bearings need somehow natured shaft measurement systems. To reduce the significant cost which are caused by the measurement systems a HALL-principle based system is proposed where low budget industrial standard sensors are applied. Contrary to other approaches the HALL-sensors are integrated between the bearing poles instead the air gap. Thus the use of low budget sensors is enabled.
BibTeX:
@inproceedings{BWMB2013_15,
  author = {Johannes Rudolph and Ralf Werner and Ivo Maximow},
  title = {Measurement of the Rotor Position of an Active Magnetic Bearing Using Interpolar Stray Flux},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_15.pdf}
}
2013 Lopes, J.S.B., dos S. Junior, L.P., de Paiva, J.A., Salazar, A.O. and Maitelli, A.L. Adaptative Neuro-Fuzzy Inference System for Estimation of Rotor Flux of a Bearingless Induction Motor applied to Speed Control Proceedings of BWMB2013  
Abstract: This study presents the problem of rotor flux orientation control of bearingless induction motor. The key of this solution is the estimation of rotor flux. This work applied an inference system using fuzzy logic and the neural networks with the MATLAB®. The Adaptive Neuro-Fuzzy Inference System (ANFIS) which is based in an input-output model is used to tune the membership functions in fuzzy system. ANFIS along with the back propagation learning algorithm was applied to estimate the rotor flux and the magnetization current for the purpose of identifying bearingless induction motor angular speed. ANFIS aims at compensating possible parametric variations of the machine caused by agents such as temperature or nucleus saturation. The simulated results showed good performance. The inference proposed system will be implemented in DSP’s.
BibTeX:
@inproceedings{BWMB2013_21,
  author = {Jose S. B. Lopes and Luciano P. dos S. Junior and Jose A. de Paiva and Andres O. Salazar and Andre L. Maitelli},
  title = {Adaptative Neuro-Fuzzy Inference System for Estimation of Rotor Flux of a Bearingless Induction Motor applied to Speed Control},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_21.pdf}
}
2013 Rodriguez, E. and Stephan, R. Radial and axial forces of a passive magnetic bearing Proceedings of BWMB2013  
Abstract: Active magnetic bearings require sensors, actuators and controllers, guaranteeing a specified dynamic behavior. Passive Magnetic Bearings, on the other hand, use simpler hardware, but do not have any dynamic control, therefore demanding improvements in the design and optimization process. This paper presents a contribution to the optimization process and dynamic behavior of PMB with permanent magnets. A single layer and two double layer configurations will be analyzed. Simulation and experimental results of static forces will be compared. Finally, experimental dynamic tests will be carried out.
BibTeX:
@inproceedings{BWMB2013_22,
  author = {Elkin Rodriguez and Richard Stephan},
  title = {Radial and axial forces of a passive magnetic bearing},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_22.pdf}
}
2013 Lorenz, F. and Werner, R. Comparison of magnetic bearings and hybrid roller bearings in a mobile flywheel energy storage Proceedings of BWMB2013  
Abstract: The comparison of active magnetic bearings and hybrid ceramic roller bearings regarding their application in a mobile flywheel energy storage is discussed in this paper. The consequences of using the two mentioned bearing types are presented concerning dynamic behavior, load capabilities, constructive parameters and reliability. To achieve a design guidance which bearing type to use two flywheel designs with the same power and capacity but different bearing concepts were simulated in a simplified drive cycle to show their different characteristics.
BibTeX:
@inproceedings{BWMB2013_23,
  author = {Fabian Lorenz and Ralf Werner},
  title = {Comparison of magnetic bearings and hybrid roller bearings in a mobile flywheel energy storage},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_23.pdf}
}
2013 Gruber, W., Bauer, W., Radman, K., Amrhein, W. and Schoeb, R.T. Considerations Regarding Bearingless Flux-Switching Slice Motors Proceedings of BWMB2013  
Abstract: The bearingless flux-switching slice motor is a compact magnetically levitated drive featuring no permanent magnets in the rotor. In this article the working principle of this novel bearingless motor topology is studied and its operational behavior is evaluated using performance factors for bearing and torque generation. Three dimensional finite element simulations are performed to optimize a promising motor variant, showing encouraging results, that will be verified in the future with the help of a prototype.
BibTeX:
@inproceedings{BWMB2013_27,
  author = {W. Gruber and W. Bauer and K. Radman and W. Amrhein and R. T. Schoeb},
  title = {Considerations Regarding Bearingless Flux-Switching Slice Motors},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_27.pdf}
}
2013 Hedlund, M., Abrahamsson, J., Perez-Loya, J.J., Lundin, J. and Bernhoff, H. Passive Axial Thrust Bearing for a Flywheel Energy Storage System Proceedings of BWMB2013  
Abstract: Two types of passive magnetic lift bearings are evaluated in terms of lift force and eddy current losses. Two sources of eddy currents are analyzed with help of the finite element method, firstly losses due to non-radial magnetization of magnets, and secondly losses due to variations in remanence. Magnets placed are placed in a Halbach array on the rotor and ring-magnets are placed on the stator. Denoted semi-segmented bearings, these produce low losses in the rotor, thus limiting the need of heat transport during vacuum operation. Experimental results of lift force are presented, together with simulations results. The losses were found to be in the order of 9 W at a rotational speed of 30 000 rpm while producing 900 N of thrust. The FEM-problem is solved with time-dependent terms, and is compared with a stationary approximation.
BibTeX:
@inproceedings{BWMB2013_3,
  author = {Magnus Hedlund and Johan Abrahamsson and Jesus Jose Perez-Loya and Johan Lundin and Hans Bernhoff},
  title = {Passive Axial Thrust Bearing for a Flywheel Energy Storage System},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_3.pdf}
}
2013 Ferreira, H.P., de M. Endalecio, A.D. and Stephan, R.M. Development of Levitation Experiments for Teaching Purposes Proceedings of BWMB2013  
Abstract: The objective of this paper is to present two magnetic levitation experiments, which give a first didactic approach to the concepts necessary to understand magnetic bearings. On the first experiment, an electrodynamic levitation system with alternating current, capable of levitating metallic rings will be presented. On the second experiment, an electromagnetic levitation system, using a Hall effect sensor to measure the levitated object position – a ferromagnetic sphere combined with permanent magnets – will be described. These laboratory rigs demonstrate the importance of simulation tools and experimental work on the verification of theoretical concepts learned in Electrical/Electronic Engineering classes.
BibTeX:
@inproceedings{BWMB2013_31,
  author = {H. P. Ferreira and A. D. de M. Endalecio and R. M. Stephan},
  title = {Development of Levitation Experiments for Teaching Purposes},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_31.pdf}
}
2013 Pesch, A.H. and Sawicki, J.T. Experimentally Based Prediction of Machining Chatter Characteristics for AMB Spindle Proceedings of BWMB2013  
Abstract: In a previous work, a high-speed spindle was made to attenuate machining chatter through application of robust control to AMB supports. In the present work, tooltip compliance of the levitated system is experimentally measured by impulse testing. Using the compliance measurement, the stability lobe diagram and critical chatter frequency diagram are calculated by means of Nyquist stability theory applied to the cutting force feedback loop. This experimentally based stability lobe diagram quantifies the improvement of machining stability when using the chatter avoiding AMB controller. The chatter frequency diagram is helpful in identifying the onset of chatter and posteriori AMB controller tuning. Also from the compliance data, critical phase shift between the inner and outer cut modulus is calculated for a range of machining speeds. The critical phase shift shows the amount of regenerative effect needed to cause machining chatter at each speed and confirms the advantageous machining speeds found in the stability lobe diagram.
BibTeX:
@inproceedings{BWMB2013_34,
  author = {Alexander H. Pesch and Jerzy T. Sawicki},
  title = {Experimentally Based Prediction of Machining Chatter Characteristics for AMB Spindle},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_34.pdf}
}
2013 David, D., Santisteban, J. and Gomes, A.D.N. Interconnected Four Poles Magnetic Bearing Proceedings of BWMB2013  
Abstract: This article analyses the adaptation of the split-wind bearingless motors structure for magnetic bearings. Preliminary theoretical results predict that a greater equivalent stiffness could be achieved when compared to the values associated with the active magnetic bearing conception traditionally described in the literature.
BibTeX:
@inproceedings{BWMB2013_36,
  author = {D.F.B. David and J.A. Santisteban and A.C. Del Nero Gomes},
  title = {Interconnected Four Poles Magnetic Bearing},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_36.pdf}
}
2013 Mizuno, T., Yoneno, Y., Ishino, Y. and Takasaki, M. Proposal of Flux-Path Control Magnetic Suspension using Flux Concentration Proceedings of BWMB2013  
Abstract: The concept of flux concentration was applied to the flux-path control magnetic suspension to increase suspension force. In the proposed system, control plates made of permanent magnet were used instead of ferromagnetic control plates in the conventional flux-interrupted type. The magnets were arranged to concentrate the flux from the magnetic source to the floator. Such effects were confirmed by magnetic field analysis. An experimental study shows that the suspension force achieved by the fluxconcentrated type was approximately 2.5 times that achieved by the flux-interrupted type with the same size. In addition, contactless suspension was achieved by applying PD control in the flux-concentrated type suspension system.
BibTeX:
@inproceedings{BWMB2013_4,
  author = {Takeshi Mizuno and Yuuki Yoneno and Yuji Ishino and Masaya Takasaki},
  title = {Proposal of Flux-Path Control Magnetic Suspension using Flux Concentration},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_4.pdf}
}
2013 Horikawa, O., Yamamoto, R.I. and da Silva, I. Development of Single Axis Controlled Attraction Type Magnetic Bearing and its Application in Ventricular Assist Device Proceedings of BWMB2013  
Abstract: Aiming the development of an implantable Ventricular Assist Device – VAD, or an artificial heart, a joint project was started in 2007, involving the Escola Politécnica of São Paulo University (EPUSP) and the Dante Pazzanese of Cardiology (IDPC). One of objectives of the project is the development of a VAD with a rotor levitated by a magnetic bearing. Here, a magnetic bearing proposed by authors, called as EPUSP bearing, is elected mainly because of its simplicity. This work presents the entire development work. One of most important work is related with the mitigation of a topology of the EPUSP bearing that enables a robust levitation, enough for supporting the rotor of a VAD. Moreover some complementary studies are developed so as to execute the Zero Power control in the EPUSP bearing, identify the best way of driving the rotor supported by the EPUSP bearing and finally, use the Hall sensor in the measurement of the rotor position in the EPUSP bearing.
BibTeX:
@inproceedings{BWMB2013_5,
  author = {Oswaldo Horikawa and Rogerio I. Yamamoto and Isaias da Silva},
  title = {Development of Single Axis Controlled Attraction Type Magnetic Bearing and its Application in Ventricular Assist Device},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_5.pdf}
}
2013 Jayawant, R. and Davies, N. Integration of Signal Processing Capability in an AMB Controller to Support Remote and Automated Commissioning Proceedings of BWMB2013  
Abstract: One major limitation to the wide adoption of active magnetic bearings (AMBs) in industry is the time required for commissioning and tuning. In this paper we will report how integration of signal processing capability (especially multi-channel transfer function measurements) within the AMB controller can reduce total commissioning time and especially, the time required on site by a highly skilled AMB specialist. We also show how PC based automatic commissioning tools make it possible for OEM and end user engineers to commission, tune and maintain AMB machines with only occasional remote support from the AMB vendor and without specialist rotor-dynamic test equipment. Secondary benefits from this approach include increased traceability and repeatability of the tuning process. The automated commissioning is based on MATLAB scripts and data analysis capabilities. This runs on a separate PC which (via the controller network interface) configures the measurements to be made by the AMB controller. Analysis of the resulting measurements allows automatic modification of controller parameters. These scripts cover several control loops and estimators within the AMB controller including current, flux and position servo control. The robustness and vibration performance are used to assess the resulting control loop. This is based around a concept of dynamic templates which correlate to acceptance criteria according to ISO 14839-2 and ISO 14839-3. Results from running the automated commissioning process on a high speed test rig are presented. The results show that the dynamic template model provides good control performance with rapid tuning time. This technology has the potential for the development of sophisticated diagnostic routines which could be activated in the event of anomalous readings, and this further future work is briefly described.
BibTeX:
@inproceedings{BWMB2013_6,
  author = {Richard Jayawant and Nigel Davies},
  title = {Integration of Signal Processing Capability in an AMB Controller to Support Remote and Automated Commissioning},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_6.pdf}
}
2013 Jayawant, R. and Dabbs, S. A Novel Digital Circuit for Position Sensor De-modulation Using Advanced FPGA, Including Field Experience with a 1.45MW Motor Driven Compressor Proceedings of BWMB2013  
Abstract: This paper describes a novel demodulation circuit which has been developed for use with inductive position sensors for Active Magnetic Bearing applications. The circuit is designed to operate with conventional bridge type inductive position sensors. This circuit is novel in that the implementation is fully digital and uses a mixture of FPGA and DSP to ensure noise immune phase sensitive de-modulation. We present the architecture and implementation of the new circuit. The techniques to perform the phase sensitive de-modulation are described, including the techniques necessary to handle the phase shifts due to cable capacitance. In conventional analogue based systems these phase shifts are compensated by field changes to component values. The experience of using this sensor on a 1.5MW motor driven hydrogen compressor is described. We present the results and experiences of commissioning the machine. The noise levels recorded during testing, and the overall response of the machine both whilst levitated (non-rotating) and during operation are included. We finish with a comparison of the two methodologies; the precision analogue circuitry versus the digital along with our conclusions.
BibTeX:
@inproceedings{BWMB2013_7,
  author = {Richard Jayawant and Steve Dabbs},
  title = {A Novel Digital Circuit for Position Sensor De-modulation Using Advanced FPGA, Including Field Experience with a 1.45MW Motor Driven Compressor},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_7.pdf}
}
2013 Kumar, P. and Jayawant, R. Commissioning Experience with Dynamic Termination of Transmission Line Effects in an Extended Magnet Cable Application Proceedings of BWMB2013  
Abstract: Active magnetic bearing controllers generate current and voltage commands in response to axial and radial forces acting on rotating shaft. The subsystems that respond to these commands are known as power amplifiers. Due to advancements in power electronics and rapid industrial trend towards higher efficiency, compactness and lower cost, recent AMB’s utilize switched mode PWM power amplifiers which regulate current in magnets by varying the ratio of on duration of switching device to switching period. With increasing no of AMB installations in hazardous areas for e.g. volatile gas compressors, it is imperative to provide a safe separation distance between the bearing and the control system itself. Transmission line effects can result in power cables connecting the PWM power amplifier to the bearing in such installations. These effects give rise to voltage and current reflections due to a mismatch of source, line and load impedance at high switching frequencies. They can cause insulation failures, overvoltage, ringing and improper operation of parts subjected to these voltages and currents. A dynamic termination circuit was developed at Waukesha Magnetic Bearings to terminate these reflections on a strategic basis according to instantaneous PWM pulse amplitude and return most of the reflected energy to the DC link power supply. This paper discusses actual results seen during commissioning on site in which an AMB system was successfully employed to suspend a volatile gas compressor rotor shaft by mitigating transmission line effects in the power cables. It is also shown that this circuit can improve dynamic performance of PWM power amplifier and meet requirements of industrial AMB’s in hazardous area applications.
BibTeX:
@inproceedings{BWMB2013_8,
  author = {Praveen Kumar and Richard Jayawant},
  title = {Commissioning Experience with Dynamic Termination of Transmission Line Effects in an Extended Magnet Cable Application},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_8.pdf}
}
2013 Schmied, J. and Kosenkov, A. Practical Controller Design for Rotors on Magnetic Bearings by Means of an Efficient Simulation Tool Proceedings of SIRM2013  
Abstract: This paper describes in detail by means of a realistic example and an efficient simulation tool the whole procedure of the magnetic bearing controller design. In a first step the suitability of the rotor is assessed. The objectives for the actual controller design to ensure a robust system, which is suited for the application, are then explained. In a first step of the design a controller structure, which is a series of proven filters with stable poles, is defined. The strategy to select the filters is determined by the rotor properties and the hardware characteristics of the bearing. The parameters of the controller are then optimized to fulfil the objectives. The optimization can be automated by the definition of suited goals, which are closely related to the objectives. Finally the performance of the resulting rotor bearing system is assessed.
BibTeX:
@inproceedings{SIRM2013_1,
  author = {Joachim Schmied and Alexander Kosenkov},
  title = {Practical Controller Design for Rotors on Magnetic Bearings by Means of an Efficient Simulation Tool},
  booktitle = {Proceedings of SIRM2013},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/sirm2013/sirm2013_submission_1.pdf}
}
2013 Grund, C. and Rotenbach, T. Untersuchungen zu einer magnetgelagerten Industriedampfurbine Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Der Einsatz aktiver Magnetlager an Turboma-schinen in Kraftwerken reduziert die Brandmasse durch den Wegfall des Ölkreislaufes zur Lagerschmierung gegenüber konventionell gelagerten Turbomaschinen erheblich und ver-ringert folglich das Gefährdungspotential. Die magnetlagerspezifisch geringe Lagerreibung führt zudem zu einer Erhöhung des Wirkungsgrades und zu einer Senkung des Wartungs- und Instandhaltungsaufwandes. Die Auswertung der inhärenten Signale der Magnetlagerung – Wellenlagen und Lagerströme – bietet zusätzliche Möglichkeiten der Überwachung und Diagnose der Magnetlager als auch des Gesamtsystems.Zur Qualifizierung des Einsatzes aktiver Magnetlager an einer Speisepumpenantriebsturbine (SPAT) im Kraftwerk wurde in einem gemeinsamen Projekt zwischen der Siemens AG, der EAAT GmbH Chemnitz und dem IPM der Hochschule Zittau/Görlitz ein Großversuchsstand konzipiert und aufgebaut. Nach der Inbetriebnahme der komplexen Anlage wurden Versuche unter praxisrelevanten Bedingungen durchgeführt. Der Beitrag gibt einen Überblick über die Ver-suchsanlage und stellt die Möglichkeiten der experimentellen Untersuchungen und erste Ergebnisse vor.
BibTeX:
@inproceedings{WMLT9_1,
  author = {C. Grund and T. Rotenbach},
  title = {Untersuchungen zu einer magnetgelagerten Industriedampfurbine },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_1.pdf}
}
2013 Düsterhaupt, S. and Worlitz, F. Komplexe und integrierte Methoden zur Zuverlässigkeitsbewertung berührungsfreier Lager Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Für den Einsatz aktiver Magnetlager in der Energietechnik muss die Zuverlässigkeit des Gesamtsystems nachgewiesen werden. Der Einsatz von Magnetlagerungen in Turbomaschinen, wie sie bspw. Turbinen, Pumpen und Verdichter darstellen, ist durch extreme Prozess- und Umgebungsbedingungen charakterisiert. Fertigungstoleranzen in den Lagerkomponenten und die Beeinflussung durch spezifische Betriebs- und Störszenarien führen zu Parameterdriften, die um die Erwartungswerte einer Nennwertauslegung streuen. Die Folge ist eine arbeitspunkt- und lastabhängige Zuverlässigkeit der Lagerkomponenten. Ein unter Nominalbedingungen funktionsfähiges aktives Magnetlager versagt ggf. aufgrund mechanischer, elektrischer oder magnetischer Parameterdriften. Die Auslegung aktiver Magnetlager soll um die Zuverlässigkeitsanalyse unter Berücksichtigung von Nichtlinearitäten erweitert werden. Dabei werden mit Hilfe geeigneter Methoden im Gegensatz zur diskreten Herangehensweise die spezifischen Lagerparameter unscharf betrachtet. Mit Hilfe der Monte- Carlo-Simulation werden im Rahmen von Simulationen Teilversagenswahrscheinlichkeiten der Komponenten ermittelt und mit Hilfe der Fehlerbaumanalyse zu einer Versagenswahrscheinlichkeit des Gesamtsystems zusammengefasst. Es wird im Auslegungsprozess ermittelt, welche Komponenten des Regelkreises redundant/diversitär ausgeführt werden müssen.
BibTeX:
@inproceedings{WMLT9_10,
  author = {S. Düsterhaupt and F. Worlitz},
  title = {Komplexe und integrierte Methoden zur Zuverlässigkeitsbewertung berührungsfreier Lager },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_10.pdf}
}
2013 Fleischer, E. and Hofmann, W. Elektromechanische Modellierung eines dreipoligen Kombilagers mittels des Lagrange-Formalismus Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Entwickelt wurde ein neuartiges dreipoliges Kombilager und erstmals Pulververbundwerkstoffe (SMC, Soft Magnetic Composite) eingesetzt. Vorgestellt wird ein elektromechanisches Simulationsmodell, das zur Verifikation des Regelsystems dient. Die angewendete Methodik auf Basis des Lagrangeschen Formalismus erlaubt eine systematische Modellierung aktiver Magnetlager als elektromechanischer Energiewandler und ber¨ucksichtigt die R¨uckwirkung der Rotorbewegung auf die Wicklungsstr¨ome, Kreiseleffekte und die magnetische Kopplung der Lagerachsen und Wicklungen. Nach einer Einf¨uhrung in den Lagrangeschen Formalismus wird seine Anwendung auf die neue Lagerstruktur gezeigt und im Experiment nachgewiesen.
BibTeX:
@inproceedings{WMLT9_11,
  author = {E. Fleischer and W. Hofmann},
  title = {Elektromechanische Modellierung eines dreipoligen Kombilagers mittels des Lagrange-Formalismus},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_11.pdf}
}
2013 Gronek, M. Qalitätsplanung in der Entwurfsphase magnetgelagerter Systeme Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Die Markteinführung neuer Technologien und Produkte bedarf einer umfangreichen Vorarbeit. Diese beinhaltet einerseits die Entwicklung des Produktes selbst, aber gleichsam bedeutend sind die Maßnahmen zur Absicherung der Produkteigenschaften hinsichtlich der Anforderungen, die es zu erfüllen gilt. Sonder- und Einzelfertigung machen den wesentlichen Anteil in der Magnetlagertechnik aus, was dem Entwicklungsaufwand und den erforderlichen Komponenten geschuldet ist. Erreicht eine Magnetlagerentwicklung die Serienreife, so muss in den überwiegenden Fällen von einer anwendungsspezifischen Kleinserie gesprochen werden. Eine tatsächliche Standardisierung, die mit konventionellen Lagerungsarten vergleichbar wäre, gibt es nicht. Der Beitrag widmet sich dem Thema der Anforderungsanalyse einerseits aus systemtechnischer Sicht und weiter gefasst auf Anforderungen vom Anwender an das Produkt Magnetlager. Es werden die Aspekte der Qualitätsplanung und Risikominimierung für sicherheitsrelevante Maschinenbaugruppen erörtert.
BibTeX:
@inproceedings{WMLT9_12,
  author = {M. Gronek},
  title = {Qalitätsplanung in der Entwurfsphase magnetgelagerter Systeme },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_12.pdf}
}
2013 Gruber, W., Bauer, W., Amrhein, W. and Schöb, R. Betrachtungen zum lagerlosen Flux-switching Scheibenläufer Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Der lagerlose Flux-Switching Scheibenläufermotor ist ein sehr kompakt aufgebauter magnetisch gelagerter Antrieb, der gänzlich ohne Permanentmagnete im Rotor auskommt. Die Funktionsweise dieser neuartigen lagerlosen Motortopologie wird in diesem Aufsatz untersucht und die Eignung für einen Betrieb als lagerloser Motor mittels Gütefunktionalen bewertet. Dreidimensionale Finite-Elemente-Simulationen für eine vielversprechende Motorvariante liefern gute Ergebnisse, die in Zukunft auch mit einem Prototyp verifiziert werden sollen.
BibTeX:
@inproceedings{WMLT9_13,
  author = {W. Gruber and W. Bauer and W. Amrhein and R. Schöb},
  title = {Betrachtungen zum lagerlosen Flux-switching Scheibenläufer },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_13.pdf}
}
2013 Lehmann, R. Alternative Abstandserfassung mit Wirbelstromsensoren Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Wirbelstromsensoren finden, neben anderen Einsatzgebieten, häufig ihre Anwendung in aktiv magnetisch gelagerten Systemen. Sie gelten als besonders robust gegenüber ihren Umgebungseinflüssen, wie zum Beispiel Staub, Luftfeuchte oder elektromagnetischen Feldern. Die unterschiedlichen Preise dieser Abstandserfassungs-Systeme spiegeln sich in ihren Möglichkeiten der Parametrierung, Synchronisierung und in der Qualität ihrer Ausgangssignale wider. Beispielsweise sind einfach gehaltene Sensorsysteme relativ preisgünstig jedoch untereinander nicht synchronisierbar wobei hingegen synchronisierbare sehr teuer sind. Ebenfalls gibt es Unterschiede im Durchmesser der Sensoren, dem Erfassungsbereich und dem Zielmaterial. Eine besonders wichtige Eigenschaft ist zusätzlich die Grenzfrequenz. Am häufigsten verbreitet sind immer noch rein analoge Sensorsysteme. In dem in diesem Beitrag beschriebenen Projekt bestand die Zielstellung darin, eine eigene Elektronik für die Positionserfassung des Rotors im Magnetlager zu entwickeln. Das Komplettgerät sollte sich insbesondere durch eine hohe Grenzfrequenz auszeichnen, preisgünstiger, synchronisierbar, kalibrierbar sowie auch für eigens entwickelte unterschiedliche Sensortypen einsetzbar sein.
BibTeX:
@inproceedings{WMLT9_2,
  author = {R. Lehmann},
  title = {Alternative Abstandserfassung mit Wirbelstromsensoren},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_2.pdf}
}
2013 Neumann, H. and Panescu, C. MFLP – Magnet- und Fanglagerprüfstand des Zitauer Krafwerkslabors Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Der Einsatz von Magnetlagern in Kraftwerksmaschinen ist oftmals durch hohe Umgebungstemperaturen und zum Teil aggressive Medien begrenzt. Gründe dafür sind der Isolationsgrad der Wicklung und der Blechung bzw. die üblicherweise eingesetzten Materialien. Für die Wicklungen liegen die max. beherrschbaren Temperaturen bei 160 °C. Bekannte Lösungen, wie zum Beispiel keramische Drahtisolierungen, die Temperaturen bis 450 °C zulassen, sind sehr aufwendig und mit einer Reihe von Nachteilen behaftet. Neueste Entwicklungen auf dem Gebiet der Oberflächentechnologie und Materialforschung erschließen völlig neue Ansätze für die Isolierung und eröffnen damit die Möglichkeit für Hochtemperaturmagnetlager (HTAMB High Temperature Active Magnetic Bearing). Da-bei müssen nicht nur die Magnetlager, sondern auch die notwendigen Fanglager in die Betrachtung mit einbezogen werden.
BibTeX:
@inproceedings{WMLT9_3,
  author = {H. Neumann and C. Panescu},
  title = {MFLP – Magnet- und Fanglagerprüfstand des Zitauer Krafwerkslabors },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_3.pdf}
}
2013 Weidenmüller, F. and Nickel, A. Aufbau des digitalen Reglers am Beispiel PID-Regler, Regleung nach dem Prinzip Lokalisation Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Magnetische Lager sind strukturinstabil. Sie benötigen in mindestens einer Achse eine aktive Lagerung. Zur Positionierung des Rotors werden schnelle Regelkreise benötigt, die auf analoger oder digitaler Basis arbeiten. Dieser Beitrag beschäftigt sich mit dem Aufbau eines schnellen digitalen Regelkreises bestehend aus Messsystemen, digitalen Reglern, Koordinatentransformation und Leistungsverstärkern. Basierend auf diesem Aufbau werden regelungstechnische Abläufe anhand von Blockschaltbildern dargestellt. Regler- und Filtergleichungen werden in Form von zeitdiskreten IIR-Filtern aufgestellt und in eine für eine Implementierung auf dem digitalen Regler notwendige Schreibweise überführt. Im ersten Teil des Beitrags liegt der Fokus auf der Stabilisierung der Lageregelkreise mit PID-Reglern. Vergleichend dazu wird im zweiten Teil die Stabilisierung mit PL-Reglern vorgestellt. Zum Schluss erfolgt eine Gegenüberstellung von Vor- und Nachteilen beider Reglerstrukturen anhand zahlreicher Kriterien. Es werden Inbetriebnahmehinweise und Erfahrungen im praktischen Aufbau einzelner Komponenten gegeben.
BibTeX:
@inproceedings{WMLT9_4,
  author = {F. Weidenmüller and A. Nickel},
  title = {Aufbau des digitalen Reglers am Beispiel PID-Regler, Regleung nach dem Prinzip Lokalisation },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_4.pdf}
}
2013 Richter, M., Schaede, H., Quurck, L. and Rinderknecht, S. Untersuchung und Erhöhung der Praxistauglichkeit sensorloser Magnetlager nach dem „Direct Digital Inductance Estimation“-Konzept Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: In diesem Beitrag wird die Praxistauglichkeit sensorloser aktiver Magnetlager nach dem Prinzip der direk-ten Induktivitätsbestimmung theoretisch und praktisch untersucht. Anders als die Modulationsverfahren verwendet das Verfahren die Form des Stromripples des Spulenstroms zur Bestimmung der Induktivität des Aktors und darüber zur Positionsbestimmung. Der Einsatz von Regelplattformen mit hoher Abtastrate und großer Rechenleistung ermöglicht eine hohe Bandbreite der Positionsbestimmung, Antialiasingfilter werden nicht benötigt. Die Untersuchungen werden an einem einachsigen Prüfstand in Differenzanordnung mit praxisnaher Aktorik durchgeführt. Die Ergebnisse zeigen, dass durch den kleinen Luftspalt und Sättigungseffekte im Eisen des Aktors die Positionsbestimmung erschwert wird. Beide Beschränkungen können allerdings durch softwareseitige Erweiterungen kompensiert werden. Weiterhin resultiert aus induzierten Wirbelströmen eine von der Frequenz der Kraftstellung abhängige Beeinflussung der Induktivität und damit der Positionsbestimmung.
BibTeX:
@inproceedings{WMLT9_5,
  author = {M. Richter and H. Schaede and L. Quurck and St. Rinderknecht},
  title = {Untersuchung und Erhöhung der Praxistauglichkeit sensorloser Magnetlager nach dem „Direct Digital Inductance Estimation“-Konzept },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_5.pdf}
}
2013 Rudolph, J., Werner, R. and Maximow, I. Messung magnetischer Streufüsse zur Bestimmung der Wellenposition im Magnetlager Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Magnetlager stellen hoch komplexe mechatronische Systeme dar. Sie eignen sich besonders für Spezialanwendungen, wie Neutronenstrahlchopper und Hochgeschwindigkeitsbearbeitungsmaschinen. Die Genauigkeit, mit der die Welle im Magnetlager positioniert werden kann, hängt maßgeblich von der Qualität der eingesetzten Messsysteme ab. Dabei stehen Eigenschaften wie Auflösungsvermögen, Genauigkeit und Dynamik in einem direkten Zusammenhang zu den Kosten, die für das Messsystem anfallen. Um den finanziellen Aufwand für die Fertigung von Magnetlagern inklusive notwendiger Sensorik zu reduzieren, wird ein Messsystem vorgeschlagen, das auf der Auswertung der magnetischen Streuflüsse außerhalb des Arbeitsluftspaltes basiert. Dazu werden zunächst theoretische Überlegungen angestellt und numerische Berechnungen durchgeführt. Die daraus abgeleiteten Aussagen werden im Anschluss durch praktische Messungen verifiziert. Im Ergebnis liegt ein Messsystem vor, auf dessen Grundlage eine stabile magnetische Lagerung ermöglicht wird.
BibTeX:
@inproceedings{WMLT9_6,
  author = {J. Rudolph and R. Werner and I. Maximow},
  title = {Messung magnetischer Streufüsse zur Bestimmung der Wellenposition im Magnetlager },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_6.pdf}
}
2013 Schleicher, A. and Werner, R. Lagerloser reluktanter Linearmotor mit gleicher Nuteilung in Ständer und Läufer Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Abstract is not available
BibTeX:
@inproceedings{WMLT9_7,
  author = {A. Schleicher and R. Werner},
  title = {Lagerloser reluktanter Linearmotor mit gleicher Nuteilung in Ständer und Läufer },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_7.pdf}
}
2013 Vanek, C., Worlitz, F. and Hecht, N. Validierung eines Gleitfanglagermodells durch Abwurfversuche Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Der Betrieb magnetgelagerter Maschinen erfordert grundsätzlich den Einsatz von Fanglagern. Diese nehmen den Rotor bei Maschinenstillstand, bei abgeschalteter Magnetlagerung oder bei Magnetlagerversagen auf. Es wird zwischen Wälz- und Gleitfanglagerungen unterschieden. Der Rotor-Fanglagerkontakt bei hohen Drehzahlen und großen mechanischen Belastungen ist durch enorme Kontaktkräfte und Relativgeschwindigkeiten zwischen Rotor und Stator gekennzeichnet. Das Fanglager muss den Rotor bis zum Stillstand sicher aufnehmen. Gegenwärtig werden bei schweren Rotoren, wie sie z. B. in Verdichtern, Pumpen und Turbinen zu finden sind, vorwiegend Wälzfanglager eingesetzt. Der komplexe Aufbau von Wälzlagern (Innenring, Außenring sowie Wälzelemente) gegenüber Gleitlagern (rotor- und statorseitige Laufbuchsen) führt, vor dem Hintergrund hoher mechanischer und thermischer Belastungen während des Eingriffes, zu erhöhten Aufwendungen bei der Konstruktion und Fertigung und damit zu hohen Kosten. Gleitfanglagerungen können eine sichere und kostengünstigere Alternative darstellen. Eine wichtige Voraussetzung dafür ist es, Gleitfanglager für solche extremen mechanischen und thermischen Belastungen an Turbomaschinen konstruktiv und werkstofftechnisch zu ertüchtigen. Für den erfolgreichen Einsatz von Gleitfanglagerlösungen ist die Beherrschung aller Ab-wurfszenarien durch das Fanglager nachzuweisen. Besonderes Augenmerk gilt hierbei den Steifigkeits- und Dämpfungswerten der Lagerung. Diese sind so zu wählen, dass der Rotor beim Durchfahren kritischer Drehzahlen im Fanglager keine unzulässig hohen Schwin-gungen auf die Maschine überträgt. Zur Sicherstellung dieser Eigenschaften sind im Vorfeld der Konstruktion für alle relevan-ten Fälle Simulationsrechnungen durchzufüh-ren. Dazu wurde das Gleitlager modelliert und Simulationsrechnungen unter Berücksichti-gung der Rotordynamik durchgeführt. Die Validierung der Modelle erfolgte auf der Grundlage von Experimenten an einem Kleinversuchsstand mit verschiedenen Gleitfanglagern. Die Ergebnisse dieser Versuche wurden zudem den Ergebnissen von Versuchen mit Wälzfanglagern am selben Versuchsstand gegenübergestellt und mit diesen verglichen. Im Beitrag werden das Gleitlagermodell und erste Simulationsergebnisse sowie die Ergebnisse der Experimente am Kleinversuchsstand vorgestellt.
BibTeX:
@inproceedings{WMLT9_8,
  author = {C. Vanek and F. Worlitz and N. Hecht},
  title = {Validierung eines Gleitfanglagermodells durch Abwurfversuche },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_8.pdf}
}
2013 Bahr, F., Melzer, M. and Karnaushenko, D. Erfassung der Lufspaltinduktion aktiver Magnetlager auf Basis ultradünner, flexibler Hall-Sensoren Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Abstract is not available
BibTeX:
@inproceedings{WMLT9_9,
  author = {F. Bahr and M. Melzer and D. Karnaushenko},
  title = {Erfassung der Lufspaltinduktion aktiver Magnetlager auf Basis ultradünner, flexibler Hall-Sensoren },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_9.pdf}
}
2012 Yu, C. and Xu, L. Auto-eliminating Clearance Auxiliary Bearings for Active Magnetic Bearing Systems Proceedings of ISMB13  
Abstract: An auto-eliminating clearance auxiliary bearing (ACAB) for Active Magnetic Bearing systems (AMBs) has been conceived and a prototype system tested. In the ACAB, a ball bearing is directly mounted on a rotor, and the outer race of the ball bearing is surrounded by a series of interconnected supporters. In the open position, a clearance exists between the outer race and the ACAB supporters. When the rotor mounted with ball bearing drop on ACAB supporter(s) due to either an AMB system failure or transient shock, the generated friction between the outer race and supporter(s) will rotate the supporters circumferentially to eliminate the clearance and re-center the ball bearing and rotor. Since the clearance is eliminated, the impact force between the outer race and supporters is reduced and the possibility of backward whirl is eliminated. This paper presents the design methodology of those supporters. And a preliminary feasibility prototype experimental rig was established under the situation of simulated AMB system failure. Experimental results demonstrate feasibility of the ACAB.
BibTeX:
@inproceedings{ISMB13_11,
  author = {Chengtao Yu and Longxiang Xu},
  title = {Auto-eliminating Clearance Auxiliary Bearings for Active Magnetic Bearing Systems},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_11.pdf}
}
2012 Grabner, H., Silber, S. and Amrhein, W. Bearingless Torque Motor - Modeling and Control Proceedings of ISMB13  
Abstract: In recent years, demands for magnetically supported direct drives which operate con-tactless and feature a high torque capacity arise in industry. This paper presents an advantageous solution for a bearingless torque motor. The proposed configuration consists of a six phase winding cofiguration with concentrated coils in double star connection to keep power electronics efforts to a minimum. The six phase winding system generates simultaneously both, the actively controlled motor torque and the radial bearing forces for radial position control. The disk shaped hollow shaft rotor carries 26 permanent mag-nets. To reduce the systems costs, tilting de ection and the axial position of the rotor are stabilized passively by the magnetic reluctance forces. The mathematical model and an appropriate control for current and voltage drivers is introduced. Finally, the prototype motor is shown with special attention to the angle and rotor position sensor evaluation.
BibTeX:
@inproceedings{ISMB13_12,
  author = {Herbert Grabner and Siegfried Silber and Wolfgang Amrhein},
  title = {Bearingless Torque Motor - Modeling and Control},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_12.pdf}
}
2012 Silber, S., Grabner, H., Lohninger, R. and Amrhein, W. Design Aspects of Bearingless Torque Motors Proceedings of ISMB13  
Abstract: In this paper novel topologies of multiphase bearingless motors featuring outstanding motor effciency and high radial force capacity are presented. For a systematic layout a simple design guideline is provided. These motors are especially suitable for applications where high torque at relatively low speed is demanded, therefore this configuration is referred to as bearingless torque motor. Since there are no dedicated bearing and motor windings the winding scheme becomes very simple and is furthermore characterized by concentrated coils only. Motor designs with different pole and slot configurations are compared by means of appropriate performance indexes. For the most promising design a demonstrator was manufactured and tested.
BibTeX:
@inproceedings{ISMB13_13,
  author = {Siegfried Silber and Herbert Grabner and Robert Lohninger and Wolfgang Amrhein},
  title = {Design Aspects of Bearingless Torque Motors},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_13.pdf}
}
2012 Wang, X. and Wang, W. Research on the Equivalent Friction Force and Power Loss of a Magnetic Bearing Proceedings of ISMB13  
Abstract: Compared with rolling bearing and sliding bearing, there is no mechanical friction and wear in magnetic bearing because there is no mechanical contact. But there is still a similar character with the mechanical friction force while magnetic bearing working. The force can be defined as an equivalent friction force for the similar to mechanical friction force. The equivalent friction force is studied and is used in calculation of power loss in magnetic bearing. It means that the power loss in magnetic bearing is equal to the equivalent friction force multiplied by the rotor speed. The definitions of the power loss in magnetic bearing and friction character are the same as those of rolling bearing and sliding bearing. A research method of equivalent friction force and power loss in magnetic bearing which is analogy of the conventional research method of rolling bearing and sliding bearing is put forward. A calculation method of power loss in magnetic bearing is presented. All of this will benefit the design of magnetic bearing system.
BibTeX:
@inproceedings{ISMB13_15,
  author = {Xiaoguang Wang and Wei Wang},
  title = {Research on the Equivalent Friction Force and Power Loss of a Magnetic Bearing},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_15.pdf}
}
2012 Marth, E., Jungmayr, G., Panholzer, M. and Amrhein, W. Optimization of Stiffness per Magnet Volume Ratio of Discrete and Continuous Halbach Type Permanent Magnetic Bearings Proceedings of ISMB13  
Abstract: To optimize stiffness per magnet volume ratio, whichs major intentions are to reduce the costs and to preserve material resources, an energy based analytical calculation method of the radial stiffness for permanent magnetic bearings with arbitrary magnetization is introduced. To simplify the calculations the stiffness is calculated from a planar model, what means that the annular ring magnets are treated as infinitely long parallel bars. The error made by neglecting the curvature effect is investigated and shows to be negligible for reasonable designs. Using this calculation method, optimal geometries for permanent magnetic ring bearings with Halbach type magnetization are presented. Thereby, discrete Halbach stacking, i.e. several stacked rings with rotating magnetization from axial to radial and so on, and continuous Halbach magnetization, i.e. one magnet that is magnetized sinusoidal, is distinguished. To show the possible improvement of stiffness per magnet volume ratio, also the characterizing values for standard single ring bearings and standard stacked structures are calculated.
BibTeX:
@inproceedings{ISMB13_16,
  author = {Edmund Marth and Gerald Jungmayr and Martin Panholzer and Wolfgang Amrhein},
  title = {Optimization of Stiffness per Magnet Volume Ratio of Discrete and Continuous Halbach Type Permanent Magnetic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_16.pdf}
}
2012 Defoy, B., Alban, T. and Mahfoud, J. Numerical Assessment of a Polar Fuzzy Controller for Centrifugal Compressors Proceedings of ISMB13  
Abstract: The aim of this study was to develop and to apply a new control approach dedicated to turbomachinery. The controller is fuzzy based usinginputs expressed in polar coordinates. The advantage is that it manages two significant physical quantities, namely tangential and radial speeds that are related to steady state and transient behaviors respectively. A simple synchronous filter is associated to the controller in order to enhance the ratio command force / bearing dynamic capacity. The approach was previously applied experimentally with success for the control of an academic test rig. It is adapted here for the control of an industrial compressor whose flexible rotor is supported by Active Magnetic Bearings (AMB). At this stage, only numerical investigations are performed. The controller has to satisfy the standards and the end users requirements. In addition, it should be easy to implement. The behavior of the machine studied is assessed for several configurations of unbalances. Tests that correspond to usual industrial excitations (subsynchronous excitation, impulse response at nominal speed) are also carried out. Results obtained are satisfactory and give insight into the potential of the approach. In addition, and as the fuzzy controller parametersare independent from the rotor design, the approach is a first step for the standardization ofmagnetic bearing controller synthesis.
BibTeX:
@inproceedings{ISMB13_17,
  author = {Benjamin Defoy and Thomas Alban and Jarir Mahfoud},
  title = {Numerical Assessment of a Polar Fuzzy Controller for Centrifugal Compressors},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_17.pdf}
}
2012 Buechsenschuetz, M. and Sattel, T. Controller Design for a High Precision Elastically Supported Hybrid Active Magnetic Guidance Proceedings of ISMB13  
Abstract: The design of multi coordinate drives (MCD) with nanometre positioning uncertainty and long planar motion range of several hundred millimetres is a worldwide research challenge. Ac-tive magnetic guidance (AMG) is suitable for these precision applications due to its non-contact support principle. One drawback is the heat generation due to ohmic loss in the control coil which should be minimized and kept constant to meet high precision demands [1, pp. 83-84]. In [2] an elastically supported hybrid active magnetic guidance (ES-HAMG) is proposed. A hybrid magnet combines a permanent magnet with a coil, additionally it is connected in series with a mechanical spring. This device is capable of reducing the thermal dissipation by 80% at varying load force on a sample ES-HAMG. This contribution gives a more comprehensive view on ES-HAMG inMCD than [2]. A model to estimate possible savings in power dissipation is derived in detail. The employed controller design theory is given. Experiments confirm theoretical energy savings and the nanopositioning capabilities.
BibTeX:
@inproceedings{ISMB13_18,
  author = {Mirko Buechsenschuetz and Thomas Sattel},
  title = {Controller Design for a High Precision Elastically Supported Hybrid Active Magnetic Guidance},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_18.pdf}
}
2012 Impinna, F., Detoni, J.G., Amati, N. and Tonoli, A. Non-dimensional design approach for Electrodynamic Bearings Proceedings of ISMB13  
Abstract: Electrodynamic bearings (EDBs) are passive magnetic bearings that exploit the interaction between eddy currents developed in a rotating conductor and a static magnetic field to generate forces. Similar to other types of magnetic suspensions, EDBs provide contactless support, thus avoiding problems with lubrication, friction and wear. The most interesting aspect of EDBs is that levitation can be obtained by passive means, hence, no electronic equipment, such as power electronics or sensors, are necessary. Despite their promising characteristics, rotors running on EDBs are still lacking a design procedure; furthermore, at present the static behavior of a bearing can only be defined by means of finite element analyses. The aim of the present paper is to present a methodology that allows performing a first approximation design without resorting to detailed FE analyses. The methodology is based on the use of non-dimensional parameters, similar to the analysis of fluid bearings (Sommerfeld number). The non-dimensional quantities are derived using dimensional analysis, and contain the main geometrical and physical parameters determining the EDBs' performance. The relation between the non-dimensional quantities characterizing the static performance of the EDB is derived using FE simulations and is presented in the form of graphs.
BibTeX:
@inproceedings{ISMB13_19,
  author = {Fabrizio Impinna and Joaquim Girardello Detoni and Nicola Amati and Andrea Tonoli},
  title = {Non-dimensional design approach for Electrodynamic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_19.pdf}
}
2012 Qian, K.-X. World-unique Permanent Maglev Turbine Reaches a Speed Over 30,000 rpm Proceedings of ISMB13  
Abstract: The author's former works on developing a permanent maglev heart pump have been questioned because the rotor of the heart pump has only ca. 20g weight and there is liquid in the pump. To levitate a heavier rotor with passive magnetic(PM) bearing and to avoid the possibility that a fluid bearing may act on the levitation of the rotor, the author applied the passive magnetic bearing in turbine machine. A prototype of permanent maglev gas turbine was developed. The device has a rotor and a stator, both radial and axial PM bearings were used to support the rotor weighing over 2kg. The gap between the rotor and the stator was 1mm, thereby no possible air bearing can be built up to support the rotor together with the PM bearings. First experiment by a model permanent maglev turbine demonstrated that the rotor's maximal eccentric distance, measured by 4 Hall sensors, would be smaller than the gap between the rotor and the stator, if the rotating speed was higher than 1800rpm, indicating that the rotor had no contact with the stator and thus was levitated stably under the action of PM bearing alone. In more extensive experiments with this prototype, the rotating speed of the device reached 30,773rpm, a value approaching that in practical application. It can be concluded that PM bearing can merely support the rotor of a gas turbine being suspended fully and stably in the stator, same as that in blood pump; this result may overturn the principle acknowledged worldwide for hundreds years that permanent maglev could not be stable.
BibTeX:
@inproceedings{ISMB13_2,
  author = {Kun-Xi Qian},
  title = {World-unique Permanent Maglev Turbine Reaches a Speed Over 30,000 rpm},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_2.pdf}
}
2012 Sun, F., Oka, K., Jin, J.J., Hong, T. and Lu, Y. Semi-Zero Power Control of a Permanent Magnetic Suspension System with Constant Air Gap Length Proceedings of ISMB13  
Abstract: This paper proposes a semi-zero power control method of a permanent magnetic suspension system using a flux path control mechanism with a constant air gap. This permanent magnetic suspension system consists of a disk-type permanent magnet, two “F� type iron cores, a rotary actuator with an encoder and a reducer, and a suspended object with a bar shape. In this system, the gravitational force of the suspended object is transmitted to the base part of the system, and the actuator only drives the permanent magnet rotate. Therefore, this system can realize the semi-zero power control. Moreover, when the mass of suspended object increases, the system just changes the bias angle of the permanent magnet, and maintains the air gap length constant. In another way, this system also can maintain the bias angle of magnet constant, and changes the air gap length short to realize the semi-zero power control. This paper focuses on the semi-zero power suspension characteristics of this system, elaborates the system’s mechanism, and analyzes the semi-zero power suspension performances with a constant air gap length.
BibTeX:
@inproceedings{ISMB13_20,
  author = {Feng Sun and Koichi Oka and Jun Jie Jin and Tao Hong and Yingyuan Lu},
  title = {Semi-Zero Power Control of a Permanent Magnetic Suspension System with Constant Air Gap Length},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_20.pdf}
}
2012 Denk, J., Köpken, H.-G., Stoiber, D. and Viering, F. Active Magnetic Bearing Systems for Turbo Machine Applications based on Standard Drive Technology Proceedings of ISMB13  
Abstract: Around two decades ago, active magnetic bearings (AMB) were introduced into O&G-applications (Oil & Gas- applications), but never gained any relevant market share in large turbomachinery. This paper discusses how standard drive technology from machine tool applications can be used to control AMB systems and how the integrated data acquisition functions simplify the commissioning process. As a proof of the concept, results of prototype testing with a 5 MW induction motor are presented.
BibTeX:
@inproceedings{ISMB13_21,
  author = {Joachim Denk and Hans-Georg Köpken and Dietmar Stoiber and Frank Viering},
  title = {Active Magnetic Bearing Systems for Turbo Machine Applications based on Standard Drive Technology},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_21.pdf}
}
2012 Mizuno, T., Nishimura, K., Ishino, Y. and Takasaki, M. Realization of Parallel-Connected Double Magnetic Suspension Proceedings of ISMB13  
Abstract: A double magnetic suspension system with parallel-connected coils is actualized in this work. The double magnetic suspension system includes a pair of subsystems, each of them has an electromagnet and a floator, and controls them by a single power amplifier solely. Double suspension systems are classified into two types based on the connection of the double coils: series connection and parallel connection. The feasibility of double magnetic suspension with series-connected coils has been already demonstrated in the previous works. This work focuses on double magnetic suspension with parallel-connected coils. The conditions for the system to be controllable are presented for its mathematical model. The feasibility of double magnetic suspension is demonstrated experimentally.
BibTeX:
@inproceedings{ISMB13_22,
  author = {Takeshi Mizuno and Kazuya Nishimura and Yuji Ishino and Masaya Takasaki},
  title = {Realization of Parallel-Connected Double Magnetic Suspension},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_22.pdf}
}
2012 Mizuno, T., Sakai, Y., Ishino, Y. and Takasaki, M. Fabrication of a New Wind Tunnel for Spinning Body Using Magnetic Suspension Proceedings of ISMB13  
Abstract: A wind-tunnel system for spinning body has been proposed to measure hydrodynamic forces acting on the body. In the proposed system, a ferromagnetic sphere (body) is suspended and rotated by electromagnets. The forces acting on the body are measured from the control signal for suspension. In this work, a wind-tunnel system with 60 60? mm was fabricated. It has eight electromagnets placed around the wind-tunnel, and a newly fabricated 3-axis optical sensor that operates in the fully differential mode. Stable suspension and three-dimensional positioning of the body were achieved in the developed system. Spinning of the body was realized by superimposing two-phase AC signals on the control signal. The hydrodynamic forces acting on the spinning body are measured successfully.
BibTeX:
@inproceedings{ISMB13_23,
  author = {Takeshi Mizuno and Yasuhiro Sakai and Yuji Ishino and Masaya Takasaki},
  title = {Fabrication of a New Wind Tunnel for Spinning Body Using Magnetic Suspension},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_23.pdf}
}
2012 Cao, G., Li, H., Huang, S., Pan, J. and Qiu, H. Development of a Control Platform for the Magnetic Suspension System Proceedings of ISMB13  
Abstract: A highly integrated open control platform for control algorithms development of magnetic suspension system is proposed based on MATLAB/Simulink, dSPACE and DSP. The schema and work principle of the control platform are presented. A robust H8controller as an example for the system is designed in detail to verify the control platform. Experimental results show that the control platform is successfully set up for carrying out research of complex control algorithms and education of control theory.
BibTeX:
@inproceedings{ISMB13_25,
  author = {Guangzhong Cao and Hanyi Li and Sudan Huang and J.F. Pan and Hong Qiu},
  title = {Development of a Control Platform for the Magnetic Suspension System},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_25.pdf}
}
2012 Okada, Y., Miyoshi, T., Masuzawa, T., Enokizono, M. and Kondo, R. Lorentz Force type Self-Bearing Motor for Centrifugal Heart Pump Proceedings of ISMB13  
Abstract: Highly efficient Lorentz force type self-bearing motor is developed. High rotor pole flux density and ampere turns of stator coils are the key technology for strong levitated motor. For this purpose Halbach magnet array and pressed flat coils are used to get high performance. The coil thickness is only 1.6 [mm] with one coil winding of 66 turns. The peak flux density in air gap is about 0.6 [T]. The rotor can run up to 9,000 [rpm] with maximum efficiency over 70 [%]. This self-bearing motor is tried to apply to the centrifugal heart pump.
BibTeX:
@inproceedings{ISMB13_26,
  author = {Yohji Okada and Tadafumi Miyoshi and Toru Masuzawa and Masato Enokizono and Ryou Kondo},
  title = {Lorentz Force type Self-Bearing Motor for Centrifugal Heart Pump},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_26.pdf}
}
2012 Zhang, W., Zhu, H. and Cao, L. Accurate Modeling of Radial Suspension Force on AC Magnetic Bearings Proceedings of ISMB13  
Abstract: This paper presents a new modeling method based on Maxwell tensor method for radial suspension forces of AC magnetic bearing. Comparing existing method, the invention explicitly designed for AC magnetic bearing is more accurate. Take the AC hybrid magnetic bearing (AC HMB) for example, this paper presents the mathematically modeling process of radial suspension forces with the proposed method. In a comparison of the model established by equivalent magnetic circuit method and by the proposed method, the high uniformity is revealed in its expression form (the only difference is the coefficient between them). To illustrate the precision of the proposed modeling approach, relevant verification experiment are designed and conducted. Indeed, the experimental results show that the proposed modeling method is more accurate than the traditional method (equivalent magnetic circuit method).
BibTeX:
@inproceedings{ISMB13_27,
  author = {Weiyu Zhang and Huangqiu Zhu and Li Cao},
  title = {Accurate Modeling of Radial Suspension Force on AC Magnetic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_27.pdf}
}
2012 Jastrzebski, R., Smirnov, A., Lin, Z., Pyrhönen, O. and Allaire, P. Extended Kalman Filter Applied to an AMB System with Strong Magnetic Saturation Proceedings of ISMB13  
Abstract: The main aim of the paper is to operate an AMB system inside the magnetically saturated region. We investigate how to stabilize a highly nonlinear AMB system with the actuator magnetic saturation by estimating the system states and parameters of the unconstrained bearing in real time. The stabilization is achieved by a combination of the controller and the extended Kalman filter to estimate the states of the plant. In the extended Kalman filter, the magnetization behavior has been modeled by using low-order piecewise polynomial approximation. The extended Kalman applied to the AMB system introduces an additional challenge because of the computational burden, numerical stability when computing the inverse of the innovation covariance matrix, and the non-continuous derivative in the computed Jacobeans. Feasibility of different control configurations is examined. As the case study we use the 1 DOF balancing beam model. The proposed solution for the system operation in the magnetic saturation provides such benefits as: the reduced size and costs of bearings, improved robust performance and stability, and an increased controllability region with respect to control variables.
BibTeX:
@inproceedings{ISMB13_28,
  author = {Rafal Jastrzebski and Alexander Smirnov and Zongli Lin and Olli Pyrhönen and Paul Allaire},
  title = {Extended Kalman Filter Applied to an AMB System with Strong Magnetic Saturation},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_28.pdf}
}
2012 Jin, C., Zhu, Y. and Xu, L. Dynamic Responses of Rotor Drops onto Double-Decker Catcher Bearing Proceedings of ISMB13  
Abstract: In an active magnetic bearing (AMB) system, the catcher bearings (CBs) are indispensable to protect the rotor and stator in case the magnetic bearings fail. Most of the former researches associated with CBs are mainly focused on the dynamic responses of the rotor drops onto traditional single-decker catcher bearings (SDCBs). Based on the analysis of the disadvantages of SDCBs, a new type of double-decker catcher bearings (DDCBs) is proposed to enhance the CB work performance in AMB system. Detailed simulation models containing rigid rotor model, contact model between rotor and inner race, DDCB model as well as SDCB model after rotor drop are established using Multi-body dynamics simulation software MSC.ADAMS. Then, using those established models the dynamic responses of rotor drops onto DDCBs and SDCBs are respectively simulated. The rotor orbits, contact forces and spin speeds of various parts after AMB failure are mainly analyzed. The simulation result shows that DDCBs can effectively improve reduce the following vibrations and impacts. Finally, rotor drop experiments choosing different types of CBs are carried out on the established AMB test bench. Rotor orbits and the rotating speeds of both inner race and intermediate races after rotor drop are synchronously measured. The experiment results verify the advantages of DDCB and the correctness of simulation analysis. The studies provide certain theoretical and experimental references for the application of DDCBs in AMB system.
BibTeX:
@inproceedings{ISMB13_29,
  author = {Chaowu Jin and Yili Zhu and Longxiang Xu},
  title = {Dynamic Responses of Rotor Drops onto Double-Decker Catcher Bearing},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_29.pdf}
}
2012 Li, P., Sahinkaya, N. and Keogh, P. Active Magnetic and Touchdown Bearings to Encourage Rotor Re-Levitation from a Persistent Contact Condition Proceedings of ISMB13  
Abstract: Magnetic bearing systems are commonly used for high speed rotor applications, having particular advantages in low pressure/vacuum environments. The benefits of using magnetic bearing systems are well documented in terms of low fiction and controllable stiffness and damping. In order to protect magnetic bearings in cases of power failure, intermittent faults and unexpected external disturbances, secondary back-up or touchdown bearings are usually included so that rotor/stator contact is prevented. If, for any reason, a rotor should make contact with a touchdown bearing, the ensuing rotor dynamic response will depend on operational parameters and any residual rotor unbalance distribution. The influence of unbalance force distributions on the contact rotor dynamics are demonstrated in this paper. Interactions between a rotor and touchdown bearings can cause relatively high contact forces that could be damaging in terms of direct mechanical stresses and through induced heat inputs when slip occurs. Inorder to alleviate the contact problem an actively controlled touchdown bearing system has been proposed to reduce contact forces and, where possible, recover rotor positional control and return it to a condition of contact-free levitation. Active touchdown bearing control may be applied together with magnetic bearing control and suggested strategies to encourage rotor contact-free levitation are assessed in this paper.
BibTeX:
@inproceedings{ISMB13_30,
  author = {Peichao Li and Necip Sahinkaya and Patrick Keogh},
  title = {Active Magnetic and Touchdown Bearings to Encourage Rotor Re-Levitation from a Persistent Contact Condition},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_30.pdf}
}
2012 Anantachaisilp, P., Lin, Z. and Allaire, P. PID Tuning Methods for Active Magnetic Bearing Systems Proceedings of ISMB13  
Abstract: The use of active magnetic bearings (AMBs) in place of traditional mechanical bearings for rotating machinery has been increasing. AMBs have been used not only in research studies, but also in a wide range of industrial applications. One of the key challenges in AMB appli-cations is the design of control systems that maintain stability in the presence of external loads and disturbances. The most commonly used controller for AMB systems is the Proportional-Integral-Derivative (PID) controller, whose design involves the tuning of control coefficients. Since manual tuning of these coefficients is time consuming, different systematic tuning methods have been developed and reported on in the literature. This paper examines some of these tuning methods in AMB control systems. Both simulation and experiments are carried out on an AMB test rig to compare the performance of the closed-loop systems resulting from these tuning meth-ods in terms of steady state accuracy and robustness. Simulation and experiments of each tuning method are conducted at rotational speeds ranging from 2,000 rpm to 11,000 rpm to evaluate the response peak (orbital size). Also, the frequency responses of the sensitivity function (S) under PID controllers tuned with different methods are measured and used to compare the robustness of the closed-loop system.
BibTeX:
@inproceedings{ISMB13_31,
  author = {Parinya Anantachaisilp and Zongli Lin and Paul Allaire},
  title = {PID Tuning Methods for Active Magnetic Bearing Systems},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_31.pdf}
}
2012 Rodriguez, E. and Stephan, R. Study of Passive Magnetic Bearings for Vertical-Axis Wind Turbines Proceedings of ISMB13  
Abstract: The increasing world energy demand as well as the necessity of environmental clean developments has turned the industry attention to improvements in renewable energy. In this context, wind power plants present technological advantages as an excellent source of clean energy. The current vertical-axis wind turbines are going to be a novel energy supplier in urban centers due to both low-cost and low-impact architectural design. Moreover, they have good performance even in the presence of turbulent winds. A magnetic suspension can greatly improve the performance, expanding the operating points to very low wind velocities. Active magnetic bearings present limiting factors such as power consumption and complexity of the system, due to sensors, power electronic circuits and the control system. In other way, passive techniques, which use permanent magnets and/or superconductors, can be alternatives in some applications. This paper presents a contribution to the design of passive magnetic bearings for vertical-axis wind turbines. Finite element simulations and experimental data will be presented.
BibTeX:
@inproceedings{ISMB13_32,
  author = {Elkin Rodriguez and Richard Stephan},
  title = {Study of Passive Magnetic Bearings for Vertical-Axis Wind Turbines},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_32.pdf}
}
2012 Zhang, J., Fang, S., Wu, H., Wang, X. and Song, C. Study on Fluid Characteristics of Centrifugal Maglev Blood Pump Proceedings of ISMB13  
Abstract: Optimal designing the magnetic bearing structure of the Centrifugal Maglev Blood Pump, then using the speed coefficient method to design a six-blade impeller and pump chamber, and using fluent software to simulate the pressure field, velocity field and flow field of the centrifugal maglev blood pump.
BibTeX:
@inproceedings{ISMB13_33,
  author = {Jinguang Zhang and Siyuan Fang and Huachun Wu and Xiaoguang Wang and Chunsheng Song},
  title = {Study on Fluid Characteristics of Centrifugal Maglev Blood Pump},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_33.pdf}
}
2012 Asama, J., Oiwa, T. and Chiba, A. Performance Improvement of a One-DOF Actively Positioned Bearingless Motor Proceedings of ISMB13  
Abstract: Conventional bearingless motors and magnetic bearings with one- to five-degrees-of-freedom (DOF) active positioning require a number of inverter modules, windings, position sensors, and electromagnets. To reduce the size and power consumption of this type of motor, the authors previously proposed a one-DOF actively positioned bearingless motor, referred to as a single-drive bearingless motor that has only one three-phase winding set and one three-phase inverter. Although the successful non-contact operation of this motor was demonstrated previously, a rotor of the test machine ran up to only 800 r/min because of serious resonance. The aim of this study was to improve the rotation performance of the single-drive bearingless motor. The cause of the rotor vibration was a discontinuous distribution of the magnetic flux density in the air-gap. One possible solution has been proposed in this paper. The test machine with an improved rotor was successfully driven up to 2000 r/min.
BibTeX:
@inproceedings{ISMB13_34,
  author = {Junichi Asama and Takaaki Oiwa and Akira Chiba},
  title = {Performance Improvement of a One-DOF Actively Positioned Bearingless Motor},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_34.pdf}
}
2012 Ishino, Y., Takasaki, M. and Mizuno, T. Development of a Solar Photovoltaic Magnetic Suspension System Proceedings of ISMB13  
Abstract: Extra low-power suspension in gravitational field is achieved by a magnetic suspension system whose power source is solely solar photovoltaics. Presently, solar photovoltaic cells become more efficient and cost-saving year by year. In this study, solar photovoltaic generation technique is combined with the zero-power magnetic suspension. The zero-power control achieves the steady state in which the attractive force produced by the permanent magnets balances the weight of the floator and the control current converges to zero. In this system, the power necessary for generating the suspension forceis very small. However, the peripheral devices including sensors and a controller need power for operation. The power consumed in the peripheral devices becomes dominant in the total power in the steady state. In this work, dedicated power-saving peripheral devices are newlyfabricated. The average power consumed in the electromagnet is 20[mW] to suspend a 90-glammass, while the power consumed in the peripheral devices is 24[mW]. The photovoltaic cells used in the apparatus has a maximum power capacity of about 2[W] in the summer sunlightof 120[kLx]. The system achieves stable suspension even under the illuminance of a fluorescent lamp of 7[kLx].
BibTeX:
@inproceedings{ISMB13_35,
  author = {Yuji Ishino and Masaya Takasaki and Takesh Mizuno},
  title = {Development of a Solar Photovoltaic Magnetic Suspension System},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_35.pdf}
}
2012 Ueno, S. and Sahinkaya, M.N. Variable Bias Current Control and Adaptive Parameter Estimation in Active Magnetic Bearings Proceedings of ISMB13  
Abstract: Reducing the energy consumption of active magnetic bearings is important for some appli-cations to reduce operating cost, expand the operating period, and avoid heat generation. The power loss of magnetic bearings consists of ohmic, electronic circuit, windage, eddy current, and hysteresis losses. With the exception of windage, these losses are functions of the coil currents, therefore, minimization of these has a significant effect on the overall energy efficiency of a mag-netic bearing. In this paper, a variable bias current scheme is introduced to minimize the energy consumption without altering the dynamic performance. Since the current stiffness and negative stiffness of the magnetic bearing are functions of the bias current, it is possible to achieve invari-ant dynamics for various bias current settings. The optimum bias current is calculated from the demand bearing force and instantaneous rotor displacement, but errors in model parameters may result in changes in system dynamics. Therefore, correct parameter values are required for invari-ant dynamics. In this paper, estimation methods for various parameter errors are introduced and verified experimentally. The proposed variable bias current controller and parameter estimation methods yield significant energy savings, are simple to implement and applicable to a wide range of magnetic bearing systems.
BibTeX:
@inproceedings{ISMB13_37,
  author = {Satoshi Ueno and M. Necip Sahinkaya},
  title = {Variable Bias Current Control and Adaptive Parameter Estimation in Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_37.pdf}
}
2012 Sugimoto, H. and Chiba, A. Precise Measurement of Suspension Force in Two-Axis Actively-Positioned Bearingless Motor for a Comparison to 3D-FEM Analysis Proceedings of ISMB13  
Abstract: Bearingless motors are required in centrifugal pumps, reaction wheels and artificial hearts for the applications in semiconductor manufacturing, space applications and medical devices, respectively. Two-axis actively regulated bearingless motors have the advantages of low cost and compactness. Only two degrees of freedom are actively regulated in the radial x-ydirections. Thus it is known that tilting motion causes seriousinterference to the radial position regulation. The interference occurs when the following three positions are not exactly corresponding; (i) the center of gravity of the rotor, (ii) the application point of the suspension force, and (iii) the position of the displacement sensors. A discrepancyin these positions causes tilting and axial displacements, which results in a reduction of radial suspension force. In this paper, a 3D-FEM analysis of the radial suspension force is carried out taking into account the rotor tilting displacement. A precise measurement method of the static radial suspension force is proposed and tested. The experiment results indicate a good correspondence to the finite element analysis.
BibTeX:
@inproceedings{ISMB13_38,
  author = {Hiroya Sugimoto and Akira Chiba},
  title = {Precise Measurement of Suspension Force in Two-Axis Actively-Positioned Bearingless Motor for a Comparison to 3D-FEM Analysis},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_38.pdf}
}
2012 Asama, J., Takemoto, M., Sugimoto, H. and Chiba, A. Performance Investigation and Power Factor Improvement of a Consequent-Pole Type Bearingless Motor Proceedings of ISMB13  
Abstract: The authors have developed a five-axis actively positioned bearingless drive system intended for a use as an industrial contamination-free centrifugal pump. It includes 1.2 kW consequent-pole type bearingless motor for torque generation and radial/tilting motion control. The aim of this paper is to investigate the motor performance with a test machine. In addition, a proposed rotor is found to improve power factor of a motor function. Based on the three-dimensional finite element method (3D-FEM) analysis, the effectiveness of the proposed structure has been verified in this paper.
BibTeX:
@inproceedings{ISMB13_39,
  author = {Junichi Asama and Masatsugu Takemoto and Hiroya Sugimoto and Akira Chiba},
  title = {Performance Investigation and Power Factor Improvement of a Consequent-Pole Type Bearingless Motor},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_39.pdf}
}
2012 Kluyskens, V. and Dehez, B. Analysis of the stability and the consumption of an electrodynamic bearing for different operation conditions Proceedings of ISMB13  
Abstract: In centering electrodynamic bearings, the guiding forces result from the interaction between eddy currents generated by a magnetic flux variation in conductors and the magnetic field. Predicting the dynamical behavior of this kind of bearings is not easy given the interactions between the electromagnetic nature of the forces and the rotational machinery aspects. In this paper, an electromechanical model, able to explain, predict, analyze and simulate the dynamical behavior of bearings submitted to eddy current forces, is applied on a homopolar null-flux electrodynamic bearing. The identification of the model’s parameters is done based on quasi-static FEM simulation results. Thanks to the insight the electromechanical model gives on the physics involved in the bearing, the dynamical stability and the stiffness of the bearing are analyzed as a function of the bearing spin speed. For various operation conditions like a constant external load or a static unbalance, the behavior of the electrodynamic bearing is simulated and examined using the electromechanical model. For all these operation conditions, the influence of the external damping, necessary to stabilize the system is analyzed. The amount of necessary damping to introduce is discussed and also its impact on the overall bearing consumption.
BibTeX:
@inproceedings{ISMB13_4,
  author = {Virginie Kluyskens and Bruno Dehez},
  title = {Analysis of the stability and the consumption of an electrodynamic bearing for different operation conditions},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_4.pdf}
}
2012 Jungmayr, G., Marth, E., Panholzer, M., Amrhein, W. and Weidenholzer, G. Fast approximate calculation of the radial and tilt stiffness of magnetic bearings using magnetostatic 2D finite element analysis Proceedings of ISMB13  
Abstract: In order to calculate the dynamic behavior of magnetically levitated rotors (eigenfrequencies, rotor deflections...), the knowledge of the radial and tilt stiffness of the active and passive magnetic bearings is necessary. An optimization of the stability against exter-nal disturbances and internal excitations (unbalance, magnetic tolerances) requires a large number of calculations of these magnetic bearing parts. Therefore, a short calculation time of the reluctance forces is crucial. As an original rotational symmetry is lost in case of a radially de ected or tilted rotor, the tilt stiffness and the radial stiffness of magnetic bearing parts are usually calculated with a 3D-FE software. These time-consuming cal-culations prevent fast optimizations of the rotor dynamics. This paper shows a method for the approximate calculation of the radial and tilt stiffness of rotationally symmetric magnetostatic problems by using a 2D-FE program. The accuracy of the approximation method will be verified by comparing the results with the exact analytical solution of a pure permanent magnetic configuration.
BibTeX:
@inproceedings{ISMB13_40,
  author = {Gerald Jungmayr and Edmund Marth and Martin Panholzer and Wolfgang Amrhein and Guenther Weidenholzer},
  title = {Fast approximate calculation of the radial and tilt stiffness of magnetic bearings using magnetostatic 2D finite element analysis},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_40.pdf}
}
2012 Masahiro, O., Toru, M. and Eisuke, T. 5-DOF control double stator motor for paediatric ventricular assist device Proceedings of ISMB13  
Abstract: We have developed a maglev ventricular assist device (VAD) for use in infant patients, which requires the device to be smaller compared to adult devices. In this research, a miniaturized axial gap maglev motor for use as a paediatric VAD is reported. In addition, radial position control theory using P±2 pole algorithm is proposed, and the feasibility of radial position control with the miniaturized axial gap maglev motor is examined by using magnetic field analysis. The double stator motor consists of a top stator, a bottom stator and a levitated rotor set between the stators which have an identical structure. A double stator mechanism has been adopted to enhance motor torque with a smaller device size and a large air-gap. The rotational speed and the axial position of the rotor are regulated independently based on a vector control algorithm. The inclination and the radial position of the rotor are regulated using P±2 pole algorithm. The designed motor which has an outer diameter of 28 mm and total height of 41 mm can produce a radial force using P±2 pole algorithm, and indicates a possibility of 5 degrees of freedom (DOF) controlled axial gap double stator motor.
BibTeX:
@inproceedings{ISMB13_41,
  author = {Osa Masahiro and Masuzawa Toru and Tatsumi Eisuke},
  title = {5-DOF control double stator motor for paediatric ventricular assist device},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_41.pdf}
}
2012 Panholzer, M., Jungmayr, G., Marth, E., Passenbrunner, J. and Amrhein, W. Performance and Dynamic Properties of an Active Axial Bearing Proceedings of ISMB13  
Abstract: In magnetically levitated systems at least one degree of freedom has to be actively stabilized. This is usually achieved with a linear magnetic actuator. If not prevented by e.g. lamination, eddy currents take place in the field conducting iron. These eddy currents have a strong effect on the field distribution in the iron and further reduce the force per current at higher frequencies. In this paper investigate the dynamic properties of a non laminated actuator biased with a permanent magnet in the rotor is anlaysed. It is shown that the voltage to force transfer function is practically unaffected by eddy currents.
BibTeX:
@inproceedings{ISMB13_42,
  author = {Martin Panholzer and Gerald Jungmayr and Edmund Marth and Josef Passenbrunner and Wolfgang Amrhein},
  title = {Performance and Dynamic Properties of an Active Axial Bearing},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_42.pdf}
}
2012 Deckert, A. Thermal-electromechanical Modeling of Magnetically Levitated Rotors under Vacuum Conditions Proceedings of ISMB13  
Abstract: This paper introduces a possibility to couple the thermal analyses of a magnetically levitated rotor, which is driven under vacuum condition, with models of its electromechanical loop. By means of this coupling, effects can be represented that are not visible when considering the ther-mal behavior and the electromechanical loop separately. The models have been parameterized for a huge number of geometrical and physical properties. The derived algorithms are implemented in MATLAB and accessible via the graphical user interface “MagBeS – Magnetic Bearing Sim-ulator�. This makes the algorithm applicable for different users and varying systems. Analyses are presented that demonstrate the interaction of the thermal and electromechanical behavior and it is shown that additional potentially critical operating modes can be identified. Furthermore, a novel approach for the experimental determination of the occurring rotor losses by means of temperature measurements and thermal analyses is presented.
BibTeX:
@inproceedings{ISMB13_43,
  author = {Antje Deckert},
  title = {Thermal-electromechanical Modeling of Magnetically Levitated Rotors under Vacuum Conditions},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_43.pdf}
}
2012 Pesch, A. and Sawicki, J. Application of Robust Control to Chatter Attenuation for a High-Speed Machining Spindle on Active Magnetic Bearings Proceedings of ISMB13  
Abstract: The purpose of this work is to demonstrate a robust control strategy to avoid machining chatter in a high-speed machining spindle levitated on active magnetic bearings. Chatter avoidance is an important aspect in machining because chatter limits the material removal rate and inhibits production. A method is implemented which uses µ-synthesis AMB control with a cutting force model in the controller design process. Such an approach causes the controller to stabilize the naturally unstable cutting process, avoiding chatter and resulting in smoother surface finish, longer tool life and increased material removal rate. Stability lobe diagrams are calculated for the new control strategy showing increased critical feed rate and confirmed through numerical simulations. The developed method is implemented experimentally on the high-speed AMB machining spindle. Impulse hammer testing is performed to measure the controlled spindle’s transfer function and evaluate chatter free machining suitability.
BibTeX:
@inproceedings{ISMB13_44,
  author = {Alexander Pesch and Jerzy Sawicki},
  title = {Application of Robust Control to Chatter Attenuation for a High-Speed Machining Spindle on Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_44.pdf}
}
2012 Mamiya, T., Hijikata, W. and Shinshi, T. A Disposable Magnetic Bearing System for an Extracorporeal Centrifugal Blood Pump Proceedings of ISMB13  
Abstract: In order to increase the design flexibility of the rotor/impeller in an extracorporeal maglev centrifugal blood pump and realize a magnet-less disposable pump head, a novel combination of a radial magnetic bearing and a magnetic coupling disk for transmitting the rotational torque from the motor, which surrounds the disposable magnet-less rotor/impeller, is proposed. The magnetic bearing system actively controls the radial motion of the rotor/impeller and passively controls motion in the other directions. Contactless stable levitation and rotation of the rotor at speeds from 0 to 3,200rpm were realized with a bearing system fabricated for a 50mm diameter rotor.
BibTeX:
@inproceedings{ISMB13_45,
  author = {Taichi Mamiya and Wataru Hijikata and Tadahiko Shinshi},
  title = {A Disposable Magnetic Bearing System for an Extracorporeal Centrifugal Blood Pump},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_45.pdf}
}
2012 Ariga, Y. and Watanabe, K. Unbalance Control of Magnetic Bearings by Multi-Degree of Freedom Internal Model Control Proceedings of ISMB13  
Abstract: This paper suggests a method to control an unbalance vibration of the magnetic bearing by multi-degree of freedom internal model controller which is called Model Bridge Control. This control method can compensate for each control problem, e.g. robust stability and uncertainty compensation, responses, disturbance rejection. By focusing on a disturbance compensator, this paper put forward a control system which rejects agitation due to unbalance. In this paper, a controller design method using a disturbance compensation characteristic of model bridge control is shown. The controller gets possible to control an unbalance forced vibration with the specific frequency by using a disturbance model. The effectiveness of the proposed method has been clarified by simulation.
BibTeX:
@inproceedings{ISMB13_46,
  author = {Yuichi Ariga and Keiji Watanabe},
  title = {Unbalance Control of Magnetic Bearings by Multi-Degree of Freedom Internal Model Control},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_46.pdf}
}
2012 Fan, Y., Liu, S. and Li, H. Application of 115kW blower supported by magnetic bearing Proceedings of ISMB13  
Abstract: Because of its superior characteristics, magnetic bearing have been applied in many fields. The topic of this paper is the control system ofmagnetic bearing in blower application. Thermal expansion effects have the impact on measurement of axial displacement, we use two eddy current sensors which are in the radial symmetrical arrangement to achieve measurement of the axial displacement, and theoreticalcalculations and experiment verified the possibility of this method.In order to reduce vibration of the rotor, a chebyshev IInotch filter is designed to suppress the special frequency, the effect of notch depth and bandwidth are discussed in the paper, through the rational allocation, the vibration of rotor are greatly suppressed; In order to improve the response of the rotor, phase compensation are used in this system, through the use of two phase compensation,the stability of the rotor rotation are improved. Simulation and experimental results show that the system has a good dynamic characteristics, the speed of the rotor is 15000rpm.
BibTeX:
@inproceedings{ISMB13_47,
  author = {Youpeng Fan and Shuqin Liu and Hongwei Li },
  title = {Application of 115kW blower supported by magnetic bearing},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_47.pdf}
}
2012 Liu, S., Bian, Z. and Cheng, Z. The application of the permanent magnet bearings in the Vertical Axis Wind Turbine Proceedings of ISMB13  
Abstract: This paper introduces the structural design of the permanent magnetic bearing for axial suspension on wind turbine, including the supporting schemes and the selection of the permanent magnetic material. The calcula-tion of the bearing capacity and the stiffness are given, and suitable stiffness can reduce the vibration caused by the changes of the wind load. Experimental comparation of wind turbines starting torque supported by the magnetic bearing and by the mechanicalbearing was carried out. And it is proved that the magnetic bearing can significantly reduce the starting torque of the wind turbine, thereby the starting wind velocity can be also reduced. Meanwhile, the wind turbine can work for a long time without lubrication, which affords lower maintenance costs, reduces the noise and greatly raises the efficiency.
BibTeX:
@inproceedings{ISMB13_48,
  author = {Shuqin Liu and Zhongguo Bian and Zhaoliang Cheng},
  title = {The application of the permanent magnet bearings in the Vertical Axis Wind Turbine},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_48.pdf}
}
2012 Li, D., Liu, S. and Bian, B. Research on the Beat Vibration of Active Magnetic Bearings Proceedings of ISMB13  
Abstract: Beat vibration is a kind of special vibration which sometimes arise in the active magnetic bearing. This vibration can smear the quality of magnetic bearings seriously. Based on the analysis of the synthesis mechanism of the beat vibration, this paper investigated the origin of the beat vibration in the magnetic bearing. According to the special electrical and machinery structure of the magnetic bearing, the source and the formation of the two sub-vibrations (the vibration with the same frequency of the rotate speed of the rotor and the vibration with the same frequency of the rotating magnetic field in induction motor) which synthesize the beat vibration were analyzed. Finally, method of inhibition of the beat vibration is given.
BibTeX:
@inproceedings{ISMB13_49,
  author = {Deguang Li and Shuqin Liu and Bin Bian },
  title = {Research on the Beat Vibration of Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_49.pdf}
}
2012 Zhang, K., Zhang, X. and Dai, X. Vibration Problems in a Turbo Molecular Pump with Active Magnetic Bearings Proceedings of ISMB13  
Abstract: In experimental tests of a proto-type 2000L turbo molecular pump suspended by 5-DOF AMBs, complex vibration problems had been met. They were caused by different reasons including rotor bending modes, rotor gyroscopic effects, pump blade modes and a vibration mode created by interaction of the dynamics of the rotor and the pump motor. They influenced the pump stability and had to be considered carefully in AMB controller designs to run the rotor to a target speed of 24000 rpm. Different methods were used to deal with these vibration problems. The gyroscopic effects were dealt with using cross feedback control methods. Other vibrations, including the bending mode vibrations, the pump blade vibrations and so on, were dealt with using phase shaping control methods. Experiment results concerning them were provided. With the suitable controller design and the appropriate consideration of the dynamic problems, the rotor was successfully accelerated to its target speed.
BibTeX:
@inproceedings{ISMB13_5,
  author = {Kai Zhang and Xiaozhang Zhang and Xingjian Dai},
  title = {Vibration Problems in a Turbo Molecular Pump with Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_5.pdf}
}
2012 Lee, J.-H. A Study on an Effect of the Flux feedback on an Open-loop Characteristic of the Magnetic Levitation System Proceedings of ISMB13  
Abstract: This paper deals with an open-loop characteristic of a magnetically levitated system including flux feedback. In order to design a controller to obtain a good disturbance rejection and to be insensitive to parameter variations, it might be useful to employ a flux feedback loop. The air gap flux which can be sensed by a proper sensor has linear relationship with respect to the change of the current and the air gap. This linear property decreases the inherent nonlinearity of the magnetic suspension system that is caused by the coupling between the electrical actuator and the mechanical plant. Simulation results show that the flux feedback loop makes an improvement of the performance of the magnetic suspension system against the load variations.
BibTeX:
@inproceedings{ISMB13_50,
  author = {Jun-Ho Lee},
  title = {A Study on an Effect of the Flux feedback on an Open-loop Characteristic of the Magnetic Levitation System },
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_50.pdf}
}
2012 Abrahamsson, J., Hedlund, M. and Bernhoff, H. Prototype of Kinetic Energy Storage System for Electrified Utility Vehicles in Urban Traffic Proceedings of ISMB13  
Abstract: This paper presents theoretical and experimental results on the ongoing construction of a high-speed (30000 rpm) kinetic energy storage system (KESS). The purpose of the device is to function as a power buffer storing up to 1kWh, primarily for utility vehicles in urban traffic. The KESS is connected in series between the primary power source and the tractionmotor of the vehi-cle. It comprises a composite rimof carbon and glass fiber in an epoxymatrix. The power to/from the rotating rim is transferred through an integrated double wound three-phase PM machine. The machine is levitated axially using four units with segmented Halbach arrays in a repulsive con-figuration. Radial centering is achieved through eight separate active electromagnetic actuators controlled by an FPGA. The geometries of the passive thrust units as well as the active actuators were designed using linked CAD and FEM tools controlled by advanced optimization algorithms. The simulated repulsive force from the thrust magnets was verified experimentally. Additionally, the corresponding negative stiffness in radial direction as well as the power loss due to induced eddy currents were simulated. The optimization of the active magnetic bearing (AMB) actuators resulted in a geometry with low resistive power loss, while generating a high current stiffness at the expense of maximum force.
BibTeX:
@inproceedings{ISMB13_51,
  author = {Johan Abrahamsson and Magnus Hedlund and Hans Bernhoff},
  title = {Prototype of Kinetic Energy Storage System for Electrified Utility Vehicles in Urban Traffic},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_51.pdf}
}
2012 Rensburg, J.J.V., Schoor, G.V. and Vuuren, P.V. The characterization of the severity of rotor delevitation events: A parametric study Proceedings of ISMB13  
Abstract: Active magnetic bearing (AMB) failure and the ensuing rotor behavior is a very important aspect of AMB safety. A model for this rotor behavior was developed and was used to characterize the severity of rotor delevitation events. The characterization was done by means of severity indicators derived from the rotor behavior within the backup bearings. The indicator is a quantitative value that can be used to compare different delevitation events. The indicator presented in this paper is the non-dimensionalised velocity of the geometric center of the rotor (Vval). This indicator only requires the rotational speed and position data of the rotor to determine the Vval quantity. This ensures that this value can be determined for most current operational systems and on historical data logged from previous rotor delevitation events. In order to validate Vval, a comparison was done between simulated and experimental rotor drops and their associated Vval values. The model used to produce the simulation results is BBSim. Experimental results were obtained on a 4-axis suspended rotor, modified to use rolling element backup bearings.
BibTeX:
@inproceedings{ISMB13_52,
  author = {Jan Janse Van Rensburg and George Van Schoor and Pieter Van Vuuren},
  title = {The characterization of the severity of rotor delevitation events: A parametric study},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_52.pdf}
}
2012 Schaede, H., Schleiffer, J.-E., Beckerle, P. and Rinderknecht, S. An Approach for the Holistic Integration of Fault Detection and Diagnosis into Active Magnetic Bearing Systems Proceedings of ISMB13  
Abstract: Present research on fault detection and diagnosis on magnetic bearing systems aims on the diagnosis of the state of single components, such as sensor and actuator faults or fault states of the plant. Although these methods often have the potential to detect more than one fault state, there is no fault detection method allowing the detection of all possible faults . This paper describes aconceptional approach to combine different fault detection methods aiming on a holistic online diagnosis of the active magnetic bearing system consisting of the functional components controller, actuator, plant and sensor. On the example of a centrifugal pump in active magnetic bearings this approach gives the possibility to combine fault detection methods detecting internal faults of the bearing system as well as the determination of the overall system status, e.g., the duty point of the pump, based on the signals of the active magnetic bearing system. This approach allows integrating new functions into the active magnetic bearing system via an enhancement of the software without changing the widely developed hardware of active magnetic bearings.
BibTeX:
@inproceedings{ISMB13_53,
  author = {Hendrik Schaede and Jean-Eric Schleiffer and Philipp Beckerle and Stephan Rinderknecht},
  title = {An Approach for the Holistic Integration of Fault Detection and Diagnosis into Active Magnetic Bearing Systems},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_53.pdf}
}
2012 Yang, B., Hu, Y. and Song, C. Study on Active Vibration Isolation Control for Electromagnetic Floating Raft Platform Proceedings of ISMB13  
Abstract: The normalized FLMS algorithm makes the convergence coefficient vary with time, which makes the adaptive process achieve a compromise between the convergence coefficient and the steady state error and overcomes the problem that the convergence factor is difficult to select, ca used by that the power of the reference signal cannot be accurately estimated or vary too fast with time. In this paper, the magnetic suspension f loating raft vibration isolation system acting as the object, the FIR filter being introduced as a feed-forward link, and the mean square error of systematic deviation operating as the performance indicators, the normalized FLMS algorithm is used for self-optimization to obtain the optimal controller parameters. The simulation results show that the normalized FLMS algorithm has better effect over convergence speed and vibration isolation compared with the ordinary FLMS algorithm. So it was applied to active control system of the magnetic suspension floating raft vibration isolation, and achieved better effect.
BibTeX:
@inproceedings{ISMB13_54,
  author = {Beibei Yang and Yefa Hu and Chunsheng Song },
  title = {Study on Active Vibration Isolation Control for Electromagnetic Floating Raft Platform},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_54.pdf}
}
2012 Kumar, P., Wright, D.D. and Jayawant, R. Sending PWM Down Extended Magnet Cables Proceedings of ISMB13  
Abstract: With a high power active magnetic bearing system, rapid changes in the magnet coil current are achieved by switching a high DC link forcing voltage onto the inductive load for short periods of time using Pulse Width modulation (PWM). In the steady state the on time of the voltage is a very small proportion of the cycle period such thatthe average voltage is sufficient to maintain the DC current through the DC resistance of the load. In some situations where it is necessary to have a large separation between the PWM driving amplifier and the load, the cable between behaves as a badly terminated transmission line. Significant reflections on the PWM pulse waveform are able to cause potentially damaging voltage overshoots up to around twice the original voltage. Conventional source and or load termination impedances would introduce unacceptable power losses. Using filters to limit the bandwidth goingdown the cable is both costly and has broadly similar effect to reducing the forcing voltage. This paper describes tests of a dynamic termination method where most of the power that would otherwise be lost is returned to the source of the DC link, giving dramatic improvement in the waveform quality.
BibTeX:
@inproceedings{ISMB13_55,
  author = {Praveen Kumar and Dr Derek Wright and Richard Jayawant},
  title = {Sending PWM Down Extended Magnet Cables},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_55.pdf}
}
2012 Victor, V.F., Lopes, J.S.B., Junior, L.D.S., Filho, J.C.D.S. and Salazar, A.O. Analysis and Study of a Bearingless AC Motor type Divided Winding, Based on a Conventional Squirrel Cage Induction Motor Proceedings of ISMB13  
Abstract: This paper shows the analysis and study of a bearingless AC Motor type divided winding for a conventional squirrel cage Induction Motor, IM. The conventional IM is used as a bearingless motor for artificial-lift oil proposes, allowing a reduction in maintenance and operation costs. The goal of this paper is improving electromagnetic forces performance, such as the Lorentz and Maxwell forces, allowing rotor positio ning at the rotation axis. It was used a simulator based on the finite element method for acquiring load results for a 375 kW, 380V, 4 -poles, 60Hz, 1.04 Nm, IM motor. Experimental results show that is possible to use a conventional IM as a bearingless motor, achieving a 80% efficiency. This paper presents simulated and experimental results that demonstrated the operation of the IM bearingless -type split coil built from a conventional induction motor.
BibTeX:
@inproceedings{ISMB13_56,
  author = {Valci F. Victor and José Soares Batista Lopes and Luciano Dos S. Junior and João Coelho De S. Filho and Andres O. Salazar},
  title = {Analysis and Study of a Bearingless AC Motor type Divided Winding, Based on a Conventional Squirrel Cage Induction Motor},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_56.pdf}
}
2012 Na, U.J. Design and Analysis of an Electromagnet Biased Integrated Radial-Axial Magnetic Bearing Proceedings of ISMB13  
Abstract: The theory for a new electromagnetically biased diskless combined radial and axial magnetic bearing is developed. A typical magnetic bearing system is composed of two radial magnetic bearings and an axial magnetic bearing. The axial magnetic bearing with a large axial disk usually limits rotor dynamic performance and makes assembling and disassembling difficult for maintenance work. This paper proposesa novel electromagnet biased integrated radial-axial magnetic bearing without axial disk. The axial magnetic bearing unit in this integrated magnetic bearing utilizes reluctance forces such that the axial disk can be removed from the bearing unit. The 4-pole homopolar type radial magnetic bearing unit is also designed and analyzed. 3-D flux analysis are also provided to illustrate the novel diskless integrated magnetic bearing.
BibTeX:
@inproceedings{ISMB13_57,
  author = {Uhn Joo Na},
  title = {Design and Analysis of an Electromagnet Biased Integrated Radial-Axial Magnetic Bearing},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_57.pdf}
}
2012 Ji, M. and Zhou, J. Identification of Support Parameters of Magnetic Bearing Based on Model Updating Method Proceedings of ISMB13  
Abstract: The stiffness and damping of magnetic bearings play an important role in the stability of high speed rotor system. In order to obtain the reliable and accurate support parameters of magnetic bearing, an identification method based on model updating is proposed in this paper. Successful identification of support parameters is based on an accurate system model. The accurate rotor model is first derived by model updating using frequency response function (FRF) data. Then, the identification of support parameters of magnetic bearings is completed by model updating method based on the unbalance response. Unbalance response of magnetic bearing rotor system with assumed initial support parameters can be calculated by the transfer matrix method. Based on an optimization algorithm, the minimum error between the calculated and measured unbalance response is achieved. The support parameters which were used to calculate the unbalance response are the identified stiffness and damping of magnetic bearings. Finally, the effectiveness and accuracy of the identification method are verified by simulation.
BibTeX:
@inproceedings{ISMB13_59,
  author = {Minlai Ji and Jin Zhou},
  title = {Identification of Support Parameters of Magnetic Bearing Based on Model Updating Method},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_59.pdf}
}
2012 Ji, L. and Xu, L. Research on an Inverter-fed Six-Pole Permanent Magnet Biased Magnetic Bearing Proceedings of ISMB13  
Abstract: The configuration and working principle of a six-pole heteropolar permanent magnet biased magnetic bearing is introduced. And the mathematical models of the suspension forces are deduced through coordinate transformation. Then the paper studies the performances of the magnetic bearing for various area ratios between the permanent magnetic pole and the electromagnetic pole. The mathematical models are verified by finite element simulation. The results show that the current stiffness error rate between theoretical calculation and finite-element simulation is less than 3%, while the displacement stiffness error rate is much greater. A controller for this magnetic bearing is designed. To confirm the controller is effective, experiments were carried out with the proposed magnetic bearing system. The results all show that the rotor can be suspended steadily and the whole control system has good dynamic and static performance with robustness. Finally, power losses tests were done. As a result, the power losses of proposed six-pole magnetic bearing are only 9.85% of the traditional eight-pole active magnetic bearing for the same bias magnetic flux density.
BibTeX:
@inproceedings{ISMB13_6,
  author = {Li Ji and Longxiang Xu },
  title = {Research on an Inverter-fed Six-Pole Permanent Magnet Biased Magnetic Bearing},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_6.pdf}
}
2012 Silvagni, M., Bonfitto, A. and Tonoli, A. Self Powered Transformer Eddy Current Damper for Vibration Control of Rotors Proceedings of ISMB13  
Abstract: The vibration control of rotors is usually performed using passive dampers, in layouts where the support of the rotating parts is achieved by rolling-element or hydrodynamic type bearings. Active magnetic bearings could be a promising however they show serious drawbacks, in terms of mass, at least when the generation of strong magnetic forces is required. Electromagnetic dampers seem a valid alternative to viscoelastic/hydraulic dampers and to active magnetic bearings because their simpler architecture, and, if of transformer type, also for the absence of power electronics, position sensors and any fast feedback loop. However transformer eddy current dampers require a constant voltage power supply (usually based on common power electronics) often integrated with active electronics components. To reduce cost, improve the reliability some applications could benefit a simplified system avoiding active components and providing the required energy with an embedded generator. The aim of the present paper is to propose a self-powered damper to fulfil these requirements. A three-phase permanent magnet electric generator (connected to the rotating shaft) generates the required power for the damping device. The generator is connected to the damping circuit by means of suitable impedance and a three-phase rectifier.
BibTeX:
@inproceedings{ISMB13_60,
  author = {Mario Silvagni and Angelo Bonfitto and Andrea Tonoli},
  title = {Self Powered Transformer Eddy Current Damper for Vibration Control of Rotors},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_60.pdf}
}
2012 Duesterhaupt, S. and Worlitz, F. Complex and Integrated Methods for the Reliability Analysis of Contactless Magnetic Bearings Proceedings of ISMB13  
Abstract: In many fields of energy technology the proof of reliability is required for the application of magnetic bearings. The application of active magnetic bearings in turbo machines for power plants is characterized by extreme process and environmental conditions. The parameters varie-gate due to manufacturing tolerances and the influence of specific operation and load conditions of the control loop components of a magnetic bearing. That involves a load-dependent reliabil-ity of the bearing components. Therefore an active magnetic bearing which is under nominal conditions in terms of its function, may fail due to drifts of mechanical, electrical and magnetic parameters. The objective of this project is the reliability analysis of active magnetic bearings considering their nonlinearities. The analysis will be carried out by means of appropriate methods which consider the specific fuzzy parameters compared to conventional approaches. The part failure probability of the several components will be determined by Monte-Carlo-Simulations. The fail-ure probability of the whole system will be summarized by use of a fault tree analysis. Whether any components have to be integrated redundantly/diversely will be determined in the early de-sign process.
BibTeX:
@inproceedings{ISMB13_61,
  author = {Stephan Duesterhaupt and Frank Worlitz},
  title = {Complex and Integrated Methods for the Reliability Analysis of Contactless Magnetic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_61.pdf}
}
2012 Yoon, S.Y., Lin, Z. and Allaire, P.E. On the Control of Single Stage Centrifugal Compressor Surge with Active Magnetic Bearings Proceedings of ISMB13  
Abstract: This paper presents a comprehensive step-by-step description of how to design and implement an Active Magnetic Bearing (AMB) based compressor surge controller, including experimental control results to demonstrate the effectiveness of the given approach. First, we provide a com-plete description of the industrial-size compressor test rig with AMBs that was specifically built for this study. Next, a detailed derivation of the dynamic equations describing the compressor flow is presented. The compressor model is later used in the synthesis of the model-based surge controller algorithm, which is implemented in the compressor test rig and tested experimentally. Illustrative details of the controller design, implementation, and testing are included.
BibTeX:
@inproceedings{ISMB13_62,
  author = {Se Young Yoon and Zongli Lin and Paul E. Allaire},
  title = {On the Control of Single Stage Centrifugal Compressor Surge with Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_62.pdf}
}
2012 Yoon, S.Y., Lin, Z. and Allaire, P.E. Iterative Tuning of Linear Quadratic Controller for AMBs in a High Speed Compressor Proceedings of ISMB13  
Abstract: This paper presents the design of an Active Magnetic Bearing (AMB) rotor radial levitation controller using an iterative tuning method developed for the Linear Quadratic Gaussian (LQG) design problem. An iterative method is used to find the ideal pair of state and input weights in the LQG objective function that result in the best performance and stability robustness characteristics of the closed-loop AMB system. A search method is used to identify a set of input weight and state weight pairs that result in AMB levitation controllers that satisfy the necessary requirements for digital implementation. Furthermore, the stability and performance requirements from the API 617 and ISO 14839 standards for new compressors with AMB support are included in the controller design process. Finally, the derived LQG rotor levitation controller is implemented on a high speed centrifugal compressor test rig with a rigid rotor. Experimental results are presented and compared to the measurements obtained with a preliminary PID controller. The measured unbalance response and rotor orbit plots demonstrate the benefits of the proposed LQG method.
BibTeX:
@inproceedings{ISMB13_63,
  author = {Se Young Yoon and Zongli Lin and Paul E. Allaire},
  title = {Iterative Tuning of Linear Quadratic Controller for AMBs in a High Speed Compressor},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_63.pdf}
}
2012 Di, L., Mushi, S., Lin, Z. and Allaire, P. Characteristic Model Based All-coefficient Adaptive Control of a Flexible Rotor Suspended on Active Magnetic Bearings Proceedings of ISMB13  
Abstract: Active magnetic bearings (AMBs) have been used in many high-speed rotating machinery ap-plications. Because of the nonlinear characteristics of magnetic bearings and complex dynamics of the flexible rotors, the problems of stabilization and disturbance rejection need to be exten-sively addressed for their smooth operation over a wide operating speed range. Conventional controller such as the proportional-integral-derivative (PID) design has played a major role in most AMB related applications. Although it is easy to implement, there exist limitations and drawbacks. The µ -synthesis approach can fulfill the requirement of robust performance, but it relies on the plant and uncertainty models, which are sometimes difficult to acquire for practical systems. This paper explores the use of the characteristic model based all-coefficient adaptive control (ACAC) method to stabilize a flexible rotor AMB system. This new control method does not require an actual model of the system. Both simulation and experimental results have shown its strong potential to perform well in spite of its simplicity.
BibTeX:
@inproceedings{ISMB13_64,
  author = {Long Di and Simon Mushi and Zongli Lin and Paul Allaire},
  title = {Characteristic Model Based All-coefficient Adaptive Control of a Flexible Rotor Suspended on Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_64.pdf}
}
2012 Palazzolo, A., Johnson, C., Thomas, E., Preuss, J., Tucker, R. and Provenza, A. Zero Gravity Test of a 40,000 RPM Flywheel Proceedings of ISMB13  
Abstract: A zero gravity flight is considered a nearly mandatory prerequisite for flight experiments on the Space Shuttle or International Space Station ISS. NASA Glenn and the Texas A&M Center for Space Power funded an effort to successfully operate a high speed 40,000 rpm flywheel during approximately 100 zero-g parabolic flight trajectories.The total flywheel energy storage system FESS was designed, built and tested at the lead author’s Texas A&M laboratory. The magnetic bearings have a fault-tolerant, homopolar design with a load capacity of about 100 lbs in the radial and axial directions. The paper includes design and fabrication details of the flywheel, magnetic suspension and the power, sensing and control systems, and also simulation and flight test results. Other magnetic bearing work presently ongoing in the lead author’s lab is also highlighted.
BibTeX:
@inproceedings{ISMB13_65,
  author = {Alan Palazzolo and Clinton Johnson and Erwin Thomas and Jason Preuss and Randall Tucker and Andrew Provenza},
  title = {Zero Gravity Test of a 40,000 RPM Flywheel},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_65.pdf}
}
2012 Maslen, E., Cloud, C.H., Hauge, T., Kibsgaard, S.T. and Lie, J.A. Unbalance Response Assessment of a Subsea Compressor Proceedings of ISMB13  
Abstract: Robustness to unbalance degradation is examined for a subsea compression application in-volving a hermetically sealed, integrated motor-compressor supported on active magnetic bear-ings. The unique rotordynamic analysis methodology employs induced infinity norm principles to determine whether various limits, such as probe vibration, seal clearances and AMB force capacities, are exceeded for worst case unbalance distributions. The compressor’s acceptability with respect to API unbalance response design criteria is examined. Additional results indicate that, by introducing speed-scheduled synchronous filter control, the machine should be able to handle significant balance degradation (approximately 7.5x the API allowable residual) before reaching the ISO recommended shutdown vibration levels. For this particular design/application, it was determined that, with the nominal feedback con-troller, the unbalance capacity is dictated by the AMB dynamic capacity, not by probe vibration or seal clearance limits. Such knowledge can be vital to the end-user and manufacturer where, if unbalance degradation capacity is less than expected for the particular service, design changes can be made to help ensure that the machine’s desired robustness and service life are achieved.
BibTeX:
@inproceedings{ISMB13_66,
  author = {Eric Maslen and C. Hunter Cloud and Trym Hauge and Svend Tarald Kibsgaard and John Arild Lie},
  title = {Unbalance Response Assessment of a Subsea Compressor},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_66.pdf}
}
2012 Turpault, S., Levine, J. and Silva, J.D. Modeling and Motion Planning of the Magnetic Vector Potential in a Nonlaminated Active Thrust Bearing System Proceedings of ISMB13  
Abstract: We propose a physical model representing a non laminated active thrust bearing system, ob-tained via Maxwell’s equations, giving the magnetic vector potential with eddy currents. We show that this model is flat in a “practical� sense. In particular, motion planning of the magnetic flux and eddy currents can be easily deduced.
BibTeX:
@inproceedings{ISMB13_67,
  author = {Stephane Turpault and Jean Levine and Joaquim Da Silva},
  title = {Modeling and Motion Planning of the Magnetic Vector Potential in a Nonlaminated Active Thrust Bearing System},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_67.pdf}
}
2012 Mushi, S., Lin, Z. and Allaire, P. Active Control of Rotordynamic Instability in Turbomachinery Proceedings of ISMB13  
Abstract: The onset of rotordynamic instability is a significant challenge to successful design and oper-ation of high speed rotating machinery particularly gas compressors. The use of active magnetic bearings (AMBs) to support gas compressor rotors presents an ideal opportunity for the explo-ration of optimal and robust active vibration control algorithms. A notable advantage of AMBs is their ability to generate optimal support stiffness and damping characteristics. Unlike passive me-chanical bearings, the support characteristics of AMBs may be modified over the operating life of the system without any major hardware changes. The objective of this paper is to demonstrate the expansion of the stability region for an experimental rotor subject to destabilizing cross-coupled stiffness. A model-based control paradigm was followed to develop nominal and uncertain dy-namic models of the rotor-bearing system. Using m -synthesis several robust controllers were designed and implemented on the MBTRI hardware to investigate their effect on the stability threshold. The best controller established a thirty-six percent increase in the stability threshold over an existing benchmark controller. This represented an increase from fifty-six percent of the maximum achievable stability threshold to seventy-six percent. A damping ratio estimation al-gorithm was used to experimentally evaluate the sensitivity of the various controllers to varying cross-coupled stiffness.
BibTeX:
@inproceedings{ISMB13_68,
  author = {Simon Mushi and Zongli Lin and Paul Allaire},
  title = {Active Control of Rotordynamic Instability in Turbomachinery},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_68.pdf}
}
2012 Nakaya, B., Komori, M., Asami, K.-I. and Sakai, N. Magnetically Levitated Conveyer Using High Tc Superconducting Magnetic Bearings (SMBs) and Its Dynamic Characteristics Proceedings of ISMB13  
Abstract: Our group has developed a new conveyer using superconducting levitation. The conveyer is com-posed of a levitated table and a conveying table. The gap between levitated table and conveying table is detected by using a Hall sensor on the superconductor. The position of the table is controlled by us-ing the PD control. In this paper we discuss a superconducting magnetic bearing (SMB) with a central superconductor. A central superconductor improves stiffness of each direction. In addition, character-istics of magnetically levitated superconducting conveyer are studied when the levitated table moves in the y direction.
BibTeX:
@inproceedings{ISMB13_69,
  author = {Bumpei Nakaya and Mochimitsu Komori and Ken-Ichi Asami and Nobuo Sakai},
  title = {Magnetically Levitated Conveyer Using High Tc Superconducting Magnetic Bearings (SMBs) and Its Dynamic Characteristics},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_69.pdf}
}
2012 Chen, S.-L. and Lin, S.-Y. Imbalance Compensation for an AMB System with Adaptive Immersion & Invariance Control Proceedings of ISMB13  
Abstract: This study is concerned with the compensationof imbalance force existing in a three-pole active magnetic bearing (AMB) system. An adaptive compensation scheme is proposed using the method of immersion and invariance (I&I) control. The main idea of I&I control is to immerse a higher-order system intoa lower-order target system. In this study, the target system will be the three-pole AMB system with known imbalance that is stabilized by an integral sliding mode controller (ISMC). In practical applications, the imbalance force may be unknown and may be changing during operation. The information of imbalance needs to be estimated online in order to realize the ISMC levitation control. To this aim, the adaptive compensation scheme is incorporated into the ISMC controller so that the closed-loop system forms the higher-order system for the design of I&I control. Numerical simulations verify the effectiveness of the proposed adaptive compensator for mass imbalance.
BibTeX:
@inproceedings{ISMB13_7,
  author = {Shyh-Leh Chen and Shyu-Yu Lin},
  title = {Imbalance Compensation for an AMB System with Adaptive Immersion & Invariance Control},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_7.pdf}
}
2012 Takahashi, W., Komori, M., Matsushita, T., Koshizuka, N., Sakai, N. and Asami, K.-I. Basic Study on Energy Storage Flywheel System With a Suspended Flywheel Rotor Proceedings of ISMB13  
Abstract: In this paper, a new model of energy storage flywheel system is proposed. The energy storage flywheel system is composed of a superconducting stator, a flywheel rotor, an induction motor and some positioning actuators. The flywheel rotor is suspended by a superconducting stator with one end fixed to a stable base. The paper discusses basic and dynamic characteristics of the energy storage flywheel system. As a result, displacements of the stator and the flywheel rotor are related with each other.
BibTeX:
@inproceedings{ISMB13_70,
  author = {Wataru Takahashi and Mochimitsu Komori and Teruo Matsushita and Naoki Koshizuka and Nobuo Sakai and Ken-Ichi Asami},
  title = {Basic Study on Energy Storage Flywheel System With a Suspended Flywheel Rotor},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_70.pdf}
}
2012 Zhang, G., Zhang, H., Wang, X., Zhang, J., Sun, C. and Zhang, J. The Electromechanical Coupling Dynamical Model of Active Maglav EMALS Proceedings of ISMB13  
Abstract: EMALS is a take-off technology used in aircraft carrier. Now the technology is successful developed in US, which proves that it is possible. This paper put forward a design scheme in which the magnetic suspension technology is used in the EMALS. An electromechanical coupling dynamical model which not only includes the five degree of freedom controlled by maglev, but also includes the sixth degree of freedom of the linear motor will be set up in this paper. The model will be useful to the further study. keywords: active maglev, EMALS, dnamics, model
BibTeX:
@inproceedings{ISMB13_71,
  author = {Gang Zhang and Hailong Zhang and Xiping Wang and Jian Zhang and Chang Sun and Jiansheng Zhang},
  title = {The Electromechanical Coupling Dynamical Model of Active Maglav EMALS},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_71.pdf}
}
2012 Wei, C. and Söffker, D. Improving PID-Control of AMB-Rotor System Design I: Optimization Strategy Proceedings of ISMB13  
Abstract: Most of the industial active magnetic bearings (AMBs) are controlled by PID-Controllers. Usually a time-consuming iterately procedure is involed to design those PID-Controllers. In this contribution an optimization strategy is developed to design a complex PID-Controller. Multi-Objective Genetic Algorithms (MOGAs) are employed as the core of the complex optimization procedure to be used. The results are studied. Core of this contribution is the development of the optimization strategy, especially the combination of frequency and time domain-based com-ponents as well as the strategy for complex PID-Controller design. For validation purposes, a comparison between simulation and experimental results are presented in part II of the contribu-tion .
BibTeX:
@inproceedings{ISMB13_73,
  author = {Chunsheng Wei and Dirk Söffker},
  title = {Improving PID-Control of AMB-Rotor System Design I: Optimization Strategy},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_73.pdf}
}
2012 Wei, C. and Söffker, D. Improving PID-Control of AMB-Rotor System Design II: Experimental Results Proceedings of ISMB13  
Abstract: Most of the industial active magnetic bearings (AMBs) are controlled by PID-Controllers. Usually a time-consuming trial and error procedure is involed to design those PID-Controllers. In part I of this contribution an optimization strategy is introduced to design a complex PID-Controller structure of higher order to be applied on an industrial AMB system. For validation purposes, the selected optimal controllers obtained by using an optimization strategy are applied to a test-rig with a flexible rotor supported by AMBs. In part I of the contribution the control algorithm parameters are optimized, in this part II, the resulting control is implemented on a Digital Signal Processor (DSP) controlling the AMB-rotor system. In combination with a test-rig experiments are performed. Within this contribution various aspects of the implementation are discussed; results are shown.
BibTeX:
@inproceedings{ISMB13_74,
  author = {Chunsheng Wei and Dirk Söffker},
  title = {Improving PID-Control of AMB-Rotor System Design II: Experimental Results},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_74.pdf}
}
2012 Zhu, C., Zhang, Q. and Chen, L. Modal Decoupling Control for Active Magnetic Bearing High-Speed Flywheel Rotor System with Strong Gyroscopic Effect Proceedings of ISMB13  
Abstract: In high-speed flywheel energy storage system, the high ratio of the polar to transverse mass moments of inertia of the flywheel rotor and the high operating speed have a great effect on the stability of the flywheel rotor system, traditional decentralized controllers, such as PID, are very difficult to deal with such rotor instability due to significant gyroscopic effect. In order to realize effectively the stability of active magnetic bearings(AMBs) supporting flywheel rotor system with strong gyroscopic effect at high rotating speeds, a new method called modal decoupling control is proposed in this paper based on mathematic model of the AMBs high-speed rigid flywheel rotor system. The principle of the modal decoupling control is introduced, and its ability and effectiveness to control the dynamic characteristics of the AMBs high-speed rigid flywheel rotor system are numerically analyzed and compared with the traditional PID controller. It is shown that the modal decoupling control proposed can separately regulate each mode’ stiffness and damping through decoupling between the conical and the parallel modes, and obviously improve the dynamic behaviors and be capacity of stabilizing the AMBs high-speed rigid flywheel rotor system with strong gyroscopic effect in the high rotating speed region.
BibTeX:
@inproceedings{ISMB13_75,
  author = {Changsheng Zhu and Qi Zhang and Liangliang Chen},
  title = {Modal Decoupling Control for Active Magnetic Bearing High-Speed Flywheel Rotor System with Strong Gyroscopic Effect},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_75.pdf}
}
2012 Fleischer, E., Tröger, S. and Hofmann, W. Control of a Novel Integrated Radial-Axial Magnetic Bearing Proceedings of ISMB13  
Abstract: An important application area of magnetic bearings is machinery running in vacuum. Examples include vacuum pumps, flywheels and spin wheels for space craft. Here even small rotor losses can overheat the rotor because of the low heat transfer in vacuum. Therefore this project aims at realizing a magnetic suspension with minimal rotor losses. Thus a novel magnetic bearing structure has been developed. It can generate both radial and axial forces and employs a minimal number of poles and soft magnetic composites as iron core material for minimal losses. This paper presents the new bearing structure and a control strategy for it. The designed controller is verified in simulations and first experimental results are presented as well.
BibTeX:
@inproceedings{ISMB13_76,
  author = {Erik Fleischer and Stefan Tröger and Wilfried Hofmann},
  title = {Control of a Novel Integrated Radial-Axial Magnetic Bearing},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_76.pdf}
}
2012 Lembke, T. 1-Dof Bearing Arrangement with Passive Radial Bearings and Highly Efficient Integrated Electrodynamic Dampers, EDD Proceedings of ISMB13  
Abstract: This paper briefly describes a novel 1-DOF bearing arrangement with integrated passive electrodynamic dampers. A general problem with passive magnetic bearings is that sufficient damping in the radial direction is difficult to provide, without using additional rubber bushings or squeeze film dampers. Electrodynamic damping schemes are sometimes proposed, but they tend to have either weak or nonlinear properties, or they contribute to additional bearing instability in terms of negative stiffness. The proposed bearing arrangement is inherently stable in terms of positive stiffness in radial direction. For dynamic stability it comprehends short circuit coils with geometries that allow for both damping coefficient and cut-off frequency to be chosen at will. A discussion on alternative coil winding schemes and possible active control is done, and finally some preliminary test results from the first prototype are presented, indicating both a stable and a linear behavior.
BibTeX:
@inproceedings{ISMB13_77,
  author = {Torbjörn Lembke},
  title = {1-Dof Bearing Arrangement with Passive Radial Bearings and Highly Efficient Integrated Electrodynamic Dampers, EDD},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_77.pdf}
}
2012 Mitterhofer, H., Amrhein, W. and Grabner, H. Comparison of two- and four-pole rotors for a high speed bearingless drive Proceedings of ISMB13  
Abstract: Bearingless drives have found their way into several industrial applications such as pumps, fans and chemical process chambers. In contrast to these drives which run at speeds below 15.000rpm, the suitability of bearingless drives for high speed has first been demonstrated with a bearingless disk drive running up to 115.000rpm in previous works by the authors. This drive uses a permanent magnet rotor with a pole number of two in order to constrain iron losses and generate the highest rotor speed with a certain electrical frequency. Other design criteria such as the rotordynamic behaviour, the radial bearing force or the torque capacity, however, might benefit from a higher pole number. Therefore, this paper will present the comparison of a two-pole and a four-pole rotor for the use in a high speed bearingless drive.
BibTeX:
@inproceedings{ISMB13_78,
  author = {Hubert Mitterhofer and Wolfgang Amrhein and Herbert Grabner},
  title = {Comparison of two- and four-pole rotors for a high speed bearingless drive},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_78.pdf}
}
2012 Bauer, W. and Amrhein, W. Design Study of Air-Core Coil Winding Topologies for Bearingless Axial-Force/Torque Motors Proceedings of ISMB13  
Abstract: The Bearingless Axial-Force/TorqueMotor is a Lorentz-Force-Type actuator featuring a com-pact and integrated design using a special permanent magnet excitation system and a slotless air gap winding. The end-windings of the concentric air-core stator coils, shaped in circumferential rotor direction, provide active suspension forces in axial direction. The actuator unifies levitation force and drive torque generation in a single device unit sharing one common winding system. Especially for single-phase motor configurations, the resulting drive topology ensures the tilt sta-bilization of the rotor. In general, only a few air gap winding structures are suitable for proper polyphase drive torque generation without any negative side effects. The present article treats the drive torque and axial force generation mechanisms for Bearingless Axial-Force/Torque Motors and its influences regarding the appearance of tilt torques. As the radial drive stabilization is realized by multiple axial displaced passive magnetic ring bearings, the radial force generation due to a mismatch of the number of rotor pole pairs and the number of stator coils is also signif-icant for drive stability considerations. As conclusion, numerical simulations for different drive configurations will prove for the validity of the presented analytical design framework.
BibTeX:
@inproceedings{ISMB13_79,
  author = {Walter Bauer and Wolfgang Amrhein},
  title = {Design Study of Air-Core Coil Winding Topologies for Bearingless Axial-Force/Torque Motors},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_79.pdf}
}
2012 Beckerle, P., Schaede, H. and Rinderknecht, S. Model-Based Fault Detection on Active Magnetic Bearings by Means of Online Transfer-Factor Estimation Proceedings of ISMB13  
Abstract: This paper gives a deeper insight in model-based fault detection based on transfer-factor esti-mation on active magnetic bearings. The method aims at performing fault detection and diagnosis at minimal computational efforts. Hence, only a limited number of transfer-factors of the inves-tigated system are considered. These are used as features for the diagnosis and represented by the magnitude and the phase at frequencies showing strong deviations between the examined states. Previously modeled faults are diagnosed by an online-estimation of the transfer-factors and a comparison to reference values. Three algorithms for this fault detection method are de-scribed and compared in detail: Recursive Least Squares (RLS), Least Mean Squares (LMS) and Goertzel-algorithm. For the comparison of the algorithms, their convergence behavior and updat-ing rate are considered as well as the computational and implementation effort. Investigations on a test rig of a centrifugal pump in active magnetic bearings show that the RLS leads to slightly slower convergence with a higher computational effort than the LMS. The Goertzel-algorithm outperforms both in computational effort, but needs several samples for the computation and thus provides a lower updating rate. Based on their findings, the authors assess suitability of the algorithms for fault detection on active magnetic bearings.
BibTeX:
@inproceedings{ISMB13_8,
  author = {Philipp Beckerle and Hendrik Schaede and Stephan Rinderknecht},
  title = {Model-Based Fault Detection on Active Magnetic Bearings by Means of Online Transfer-Factor Estimation},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_8.pdf}
}
2012 Li, J., Xiao, K., Liu, K. and Hou, E. Mathematical Model of a Vernier Gimballing Momentum Wheel Supported by Magnetic Bearings Proceedings of ISMB13  
Abstract: Based on rotor dynamics and gyro dynamics, the mathematical model for a vernier gimballing momentum wheel supported by magnetic bearings was established to analyze the forces and torques generated by the wheel body . The static and couple unbalances of the structure are regarded as two main sources causing periodic disturbances to the stability of the system. Since the rotational speed of the rotor is high, the gyroscopic effect is also an important factor causing interference on the stability. Therefore, the effects of disturbances from above are considered to make the mathematical model be closer to the real state.
BibTeX:
@inproceedings{ISMB13_80,
  author = {Jiayi Li and Kai Xiao and Kun Liu and Eryong Hou},
  title = {Mathematical Model of a Vernier Gimballing Momentum Wheel Supported by Magnetic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_80.pdf}
}
2012 Bahr, F., Melzer, M., Karnaushenko, D., Makarov, D., Karnaushenko, D., Mönch, J.I., Malane, D., Schmidt, O.G. and Hofmann, W. Flux Based Control of AMBs Using Integrated Ultra-Thin Flexible Bismuth Hall Sensors Proceedings of ISMB13  
Abstract: To increase stiffness and precise rotor positioning of active magnetic bearings (AMB), flux based control algorithms were suggested. However, the typical thickness of air gaps in AMBs is too small to apply conventional magnetic field sensors with a typical thickness of more than 500 µm. Furthermore, the curved surfaces of the sta tor poles require a mechanically flexible sensor design. Here, we propose a flexible Bismuth based Hall sensor with a total thickness of only 80 µm including encapsulation. After wiring th e sensors have a maximum height of 280 µm and could be mounted onto curved surfaces. T he fabricated sensors were characterized and the influence of size, temperature and bending radius on the Hall sensitivity was determined. On a proof-of-concept level we demonstrated the performance of the flexible magnetic field sensors to control an one-axis AMB with a levitating ball. Several algorithms using flux density measurements were tested and compared to conventional control strategies.
BibTeX:
@inproceedings{ISMB13_81,
  author = {Falk Bahr and Michael Melzer and Daniil Karnaushenko and Denys Makarov and Dmitriy Karnaushenko and Jens Ingolf Mönch and Dominic Malane and Oliver G. Schmidt and Wilfried Hofmann},
  title = {Flux Based Control of AMBs Using Integrated Ultra-Thin Flexible Bismuth Hall Sensors},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_81.pdf}
}
2012 Gruber, W., Briewasser, W., Rothböck, M., Schöb, R. and Amrhein, W. Bearingless Reluctance Slice Motors Proceedings of ISMB13  
Abstract: Bearingless permanent magnet motors are very compact and favorable for high speed designs. Especially the bearingless slice motor (using a permanent magnet excited rotor disc) features a mechanically simple and very cost effective fully magnetically levitated system by stabilizing some degrees of freedom by permanent magnetic reluctance forces. This work focuses on constructional possibilities to apply the slice rotor principle with its passive stabilization without any permanent magnetsin the rotor part. As a matter of fact, the permanent magnets are necessary and are therefore located in the stator. Possible stator compositions are outlined and separated into homopolar and heteropolar permanent magnet air gap flux types. The definition of performance parameters allows evaluating the operational behavior of the two considered bearingless reluctance slice motor types (one with hompolar and one with heteropolar air gap flux distribution). The composition, optimization and construction of a prototype are outlined in the last section. Measurements are conducted to show the proper functionality of the bearingless reluctance slice motor prototype.
BibTeX:
@inproceedings{ISMB13_82,
  author = {Wolfgang Gruber and Wolfgang Briewasser and Michael Rothböck and Reto Schöb and Wolfgang Amrhein},
  title = {Bearingless Reluctance Slice Motors},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_82.pdf}
}
2012 Kato, T., Takasaki, M., Mizuno, T. and Bleuler, H. Concept of Displacement Sensor Using Resonant Inductive Coupling Proceedings of ISMB13  
Abstract: This paper presents the concept of a novel displacement sensor based on resonant inductive coupling. Resonant inductive coupling uses two coils or LC circuits similarly to an electromagnetic induction. The electromagnetic induction, that is the principle of transformer, is also an interaction of magnetic fields in usually akilohertz-range. It is used for power transfer and operated with a small gap. A power transmissionwith rather larger gap is possible by using a megahertz-range resonance. Resonant inductive coupling is actively studied in the field of wireless power transfer recently. Meanwhile, some AMB systems need a displacement sensor operating with a large air gap. Thus, the resonant inductive coupling is applied to a displacement sensor. It can achieve high resolution (sub-mm) over a very large distance (10cm). In this paper, the principle of resonant inductive coupling is explained. Several basic results are shown, and these results are evaluated as a displacement sensor.
BibTeX:
@inproceedings{ISMB13_83,
  author = {Takaaki Kato and Masaya Takasaki and Takeshi Mizuno and Hannes Bleuler},
  title = {Concept of Displacement Sensor Using Resonant Inductive Coupling},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_83.pdf}
}
2012 Filatov, A. and Hawkins, L. Constant-Flux Edge Sensor Proceedings of ISMB13  
Abstract: A novel axial position sensor is presented. The sensor offers a unique combination of advantageous properties not found collectively in other axial position sensing solutions. These include ability to work in dusty environments and in many working fluids, low sensitivity to temperature as well as external electricaland magnetic fields, good linearity over a large displacement range, large intrinsic gain, easy integration into a machine, robustness to the variations in parametersof the external wiring, simplicity of the signal processing electronics, sufficient frequency bandwidth and a commonality of used elements with radial magnetic reluctance position sensors. This paper describes the operating principle, test procedure and test results of the constant-flux edge sensor in both single-sided and differential configurations. Presently the sensor has been successfully integrated into several commercial machines and extensively tested under various operating conditions.
BibTeX:
@inproceedings{ISMB13_84,
  author = {Alexei Filatov and Larry Hawkins},
  title = {Constant-Flux Edge Sensor},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_84.pdf}
}
2012 Mcmullen, P. and Hawkins, L. Long Term Backup Bearing Testing Results Proceedings of ISMB13  
Abstract: An energy storage flywheel was developed in 2005 to provide ride-through power for industrial UPS applications, and its application was expanded to provide regeneration power for mobile cranes. The flywheel, which operates in a vacuum, is supported by Active Magnetic Bearings (AMB) to minimize bearing losses, and has a high power motor/generator coupled to an efficient power conversion module. The flywheel can maintain energy for emergency use by holding at full speed or can be cycled up and down in speed to absorb and discharge energy rapidly. Over 400 Flywheel systems have been delivered and are operating in the field since product release. In addition to the AMB, the Flywheel system uses a backup bearing system to support the rotor; 1- when the system is not in operation, including shipping; 2- during low speed safe spin-downs when external power is disconnected, 3- during intermittent overload events (only expected in crane systems as a result of crane motion) and 4- during high speed spin-downs when system events/failures occur. Low speed spin-downs typically start at 4,000 rpm in crane systems and can happen multiple times a day, while UPS systems typically start at 6,000-8,000 rpm and may only happen once a year. Overloadevents in crane systems can happen at any speed in the operation range of 10,000 rpm to18,000 rpm and last for up to 5 seconds. The backup bearing system of every flywheel is tested with a series of backup bearing drop tests culminating with a drop and spin down from full speed. Additionally, several engineering flywheels have been used extensively for testing and development of the backup bearing system. The original system was capable of three 2.75 hour spin downs from 36,000 rpm and developed with the UPS system requirements in mind. Methodology and results for this test program were described in [1] and [2]. Recent testing has validated the system for use in crane system with added low speed spin-downs and momentary overload conditions at high speeds. In addition, incremental changes to the backup bearing system have resulted in extending the capability to eight 2.75 hour spin downs from 36,000 rpm for UPS applications. These changes are the result of continued analysis of backup bearing operation during spin-down. This ongoing test program is reported here – including a discussion of some of the test results.
BibTeX:
@inproceedings{ISMB13_85,
  author = {Patrick Mcmullen and Larry Hawkins},
  title = {Long Term Backup Bearing Testing Results},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_85.pdf}
}
2012 Shultz, R. and Yates, S. Landing Test Results for a 6 MW Motor Compressor and Auxiliary Bearing Systems for Corrosive Environments Proceedings of ISMB13  
Abstract: Auxiliary bearing landing tests have been conducted on a 6 MW vertical motor compressor. The corrosion resistant auxiliary bearing system for the motor compressor is a unique combination design with one auxiliary bearing of bushing type design and the other, a rolling element type design. The results of the landing test were good, with 5 landings completed and with the auxiliary bearings fit for further service. Corrosion resistant auxiliary bearing designs are described. Analysis methods and design considerations for auxiliary bearing systems are discussed.
BibTeX:
@inproceedings{ISMB13_86,
  author = {Richard Shultz and Simon Yates},
  title = {Landing Test Results for a 6 MW Motor Compressor and Auxiliary Bearing Systems for Corrosive Environments},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_86.pdf}
}
2012 Sun, Z., Zhao, J. and Yu, S. Nonlinear Nonparametric Identification of Magnetic Bearing System Based on Support Vector Regression Proceedings of ISMB13  
Abstract: The mathematical model of components in an active magnetic bearing system plays important roles in system designing and adjusting. The linearized models are widely applied; however, sometimes these models are not precise enough. In this paper, a nonlinear modeling method based on Support Vector Regression (SVR) is proposed. The proposed model treats the rotor acceleration as a nonlinear function of the rotor displacement, rotor velocity and the coil currents; the model parameters are determined by a training procedure based on observed samples, no mechanism, computational or empirical models are needed in the modeling procedure. The proposed method is validated by a series of experiments.
BibTeX:
@inproceedings{ISMB13_87,
  author = {Zhe Sun and Jingjing Zhao and Suyuan Yu},
  title = {Nonlinear Nonparametric Identification of Magnetic Bearing System Based on Support Vector Regression},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_87.pdf}
}
2012 Mo, N., Shi, Z., Zhou, Y. and Yu, S. Study on eddy current loss for active magnetic thrust bearings considering load variation, noise, and switching ripple currents Proceedings of ISMB13  
Abstract: Calculation of eddy current loss is an essential job in magnetic thrust bearings(MTBs) design in specific applications. In this work, a comprehensive model of eddy current loss in MTBs is presented. In this model, a fractional-order dynamic model is applied. The model parameters are estimated by heuristic optimization algorithm. The close loop model is constructed with the dynamic current stiffness and displacement stiffness. In this model, the load variation and sensor noise are considered. The eddy current loss brought by load variation and sensor noise is analyzed then. A pulse width modulation(PWM) switching power amplifiers(SPA) is also modeled and the switching ripple current(SRC) is calculated by finite element analysis(FEA). This result is applied to calculate the loss brought by SRC. According to the simulation results, it is concluded that the heat by SRC is dominant in common applications.
BibTeX:
@inproceedings{ISMB13_88,
  author = {Ni Mo and Zhengang Shi and Yan Zhou and Suyuan Yu},
  title = {Study on eddy current loss for active magnetic thrust bearings considering load variation, noise, and switching ripple currents},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_88.pdf}
}
2012 Kailasan, A., Jiang, W., Dimond, T., Sheffler, D. and Allaire, P. Design and analysis of the magnetic suspension system in an energy storage flywheel Proceedings of ISMB13  
Abstract: Over the past decade, there has been a rising need to develop more efficient, sustainable and environmentally friendly means of short term energy storage. Flywheel energy storage systems store kinetic energy by continuously spinning a compact rotor in a low-friction environment. Magnetic bearing suspension systems are desirable for this application since they significantly increase efficiency, reduce waste heat when operated in vacuum and reduce power requirements for the electronics. A demonstration flywheel energy storage test rig under development at the University of Virginia will use a five-axis active magnetic bearing support system. This paper discusses the design and analysis procedure of the flywheel magnetic suspension system. The magnetic suspension system will be controlled by a µ-synthesis controller, with an adaptive auto-balancing algorithm. Preliminary calculations are performed to determine the various design parameters such as nominal air gap, number of coil turns required, and stator/rotor diameter and thickness using linear magnetic circuit models. Finally, a 3-dimensional finite element analysis was conducted with commercial finite element software to verify the calculated design parameters. The flux path was visualized for both the thrust a nd radial magnetic bearings and important parameters such as load capacity, flux density, inductance and slew rate were calculated.
BibTeX:
@inproceedings{ISMB13_89,
  author = {Arunvel Kailasan and Wei Jiang and Timothy Dimond and David Sheffler and Paul Allaire},
  title = {Design and analysis of the magnetic suspension system in an energy storage flywheel},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_89.pdf}
}
2012 Fan, Y.-H., Lee, Y.-T., Chung, W.-C., Su, C.-X. and Lin, C.-H. Design of a Variable Structure Controller Based on the Force Estimator for a Single Active Magnetic Bearings Suspended Rotor System Proceedings of ISMB13  
Abstract: This study proposes a variable structure controller with a force estimator for a single active magnetic bearing suspended rotor system to eliminate the vibration associated with unbalance of mass. The model of a single active magnetic bearing suspended rotor system is build and a displacement and unbalancing force estimator of the system is established. A variable structure controller is also established according to the estimated force to decrease the influence of the unbalance force and increase the robust of the system. The experimental results showed that thevariable structure controller based on the force estimator for a single active magnetic bearing suspended rotor system was established successfully and has good accuracy.
BibTeX:
@inproceedings{ISMB13_90,
  author = {Yi-Hua Fan and Ying-Tsun Lee and Wei-Cheng Chung and Chong-Xian Su and Chung-Hsien Lin},
  title = {Design of a Variable Structure Controller Based on the Force Estimator for a Single Active Magnetic Bearings Suspended Rotor System},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_90.pdf}
}
2012 Kodochigov, N.G., Pobedonostsev, A.B., Ovchinnikov, V.F. and Drumov, I.V. Development and Testing of the Code and Procedure for Balancing the Flexible Vertical Electromagnetically Suspended Rotor Proceedings of ISMB13  
Abstract: It is known that the basic component of forces, which affects electromagnetic bearings (EMB), is centrifugal forces produced by the unbalanced rotor. The unbalanced forces must be reduced to the allowed level for the entire frequency band, including critical frequencies (GOST ISO 11342). For effective balancing, balancing weights shall be installed in accordance with actual rotor bending modes. Therefore, under research and development work carried out in JSC "Afrikantov OKBM" (Russia) activities are performed aimed at studying possibilities for balancing the flexible vertical rotor using EMBs in the machine. During this work, the special BALANS code and procedure for balancing the flexible rotor using EMBs were developed. At a small test facility having the vertical rotor [1, 2], experimental investigations were carried out to balance the flexible rotor using EMBs. Based on preliminary results, it is possible to balance the flexible vertical rotor using EMB without balancing the rotor in factory conditions. In 2011, JSC "Afrikantov OKBM" carried out work to balance the vertical rotor using electromagnetic suspension in the large test facility, i.e. in the Turbomachine (TM) Rotor Scale Model (RSM).
BibTeX:
@inproceedings{ISMB13_91,
  author = {N. G. Kodochigov and A. B. Pobedonostsev and V. F. Ovchinnikov and I. V. Drumov},
  title = {Development and Testing of the Code and Procedure for Balancing the Flexible Vertical Electromagnetically Suspended Rotor},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_91.pdf}
}
2012 Kodochigov, N.G., Drumov, I.V. and Malkin, S.A. Analysis and Experiment Results of Reactor Plant Turbomachine Rotor Model Investigations Proceedings of ISMB13  
Abstract: Analysis and experiment results of reactor plant turbomachine rotor model investigations are described. It is shown that application of linearization by feedback to produce the control algorithm allows system linearizing without use of bias current. The system linearized in this way has better dynamic qualities, particularly, the frequencies in rotor oscillation spectrum, which are different from rotation speed, are eliminated.
BibTeX:
@inproceedings{ISMB13_92,
  author = {N. G. Kodochigov and I. V. Drumov and S. A. Malkin},
  title = {Analysis and Experiment Results of Reactor Plant Turbomachine Rotor Model Investigations},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_92.pdf}
}
2012 Toh, C.S., Chen, S.L. and Juang, D.P. Development of a Ring-type Flywheel Battery System for Storage of Renewable Energy Proceedings of ISMB13  
Abstract: In this study, a small scale prototype of a ring-type flywheel battery system is designed and fabricated. The system consists of 5-DOF magnetic bearing and a built-in motor/generator. The magnetic bearing is of hybrid type, with passive axial magnetic bearing and active radial magnetic bearing. For the passive axial magnetic bearing, a pair of Halbach arrays of permanent magnets are arranged vertically to support the weight of rotor and flywheel. For the active radial magnetic bearing, a set of Halbach array is placed on the rotor side, which will correspond to a coil set on the stator side. The active magnetic bearing can produce both attraction and repulsion forces on the radial direction, depending on the direction of the coil currents. When driven by an active feedback control system operating in conjunction with a position sensor, the actuator force can be used to balance the lateral forces coupled from the passive axial magnetic bearing and to achieve stable levitation. In the radial magnetic bearing, the design of eight-pole and differential winding mode are applied, which can result in a linear force-current relation. Hence, the system can be modeled by a simple linear time-invariant system. For robustness, the controller is designed by integral sliding mode control (ISMC) to overcome the effects of uncertainty and to achieve good steady-state accuracy. Numerical simulation results verify the effectiveness of the controller. To further validate the efficiency of the proposed controller, the experiments of the prototype are also performed.
BibTeX:
@inproceedings{ISMB13_93,
  author = {Chow Shing Toh and Shyh Leh Chen and Dar Ping Juang},
  title = {Development of a Ring-type Flywheel Battery System for Storage of Renewable Energy},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {http://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_93.pdf}
}
2011 Vanek, C. and Worlitz, F. Experimentelle und theoretische Untersuchungen zum Rotorabsturz in Wälzlager Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Um eine Auslegung von Fanglagern durchzuführen ist es notwendig, die Belastungen dieser in den zu erwartenden Abwurfszenarien zu kennen. Da so ein chaotischer Vorgang schwer analytisch berechnet werden kann, ist es erforderlich, ein dynamische Simulationendurchzuführen. Der Beitrag soll einen Einblick in die experimentellen Arbeiten geben, welche zur Validierung eines solchen Berechnungsmodells nötig sind. Dabei soll vor allem auf einen Qualitätsfaktor eingegangen werden, welcher es ermöglicht verschiedene Fanglagerabwürfe mit Hilfe eines normierten Faktors zu vergleichen. Weiterhin wird auf den Einfluss des Auftreffwinkels des Rotors im Fanglager eingegangen, sowie einige Beispiele für die Anwendung des Qualitätsfaktors gegeben.
BibTeX:
@inproceedings{WMLT8_1,
  author = {C. Vanek and F. Worlitz},
  title = {Experimentelle und theoretische Untersuchungen zum Rotorabsturz in Wälzlager},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_1.pdf}
}
2011 Rudolph, J., Budig, P.-K. and Werner, R. Theoretische und praktische Betrachtungen zur Schwingungsdämpfung in permanentmagnetisch gelagerten Systemen Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Schwungradenergiespeichers können permanentmagnetische Lager eingesetzt werden. Diese arbeiten nahezu reibungsfrei und damit verlustarm. Technisch gesehen stellt solch ein Lager ein schwingfähiges Feder-Masse-System dar. Dies macht zusätzliche Maßnahmen zur Dämpfung notwendig. In dem vorliegenden Beitrag werden zunächst Möglichkeiten der Dämpfung rotierender permanentmagnetisch gelagerter Wellen vorgestellt und diskutiert. Aufgrund der getroffenen Aussagen wird ein permanentmagnetischer Dämpfungsmechanismus theoretisch sowie praktisch untersucht. Durch Magnete, die sich radial mit der Welle bewegen, wird in einer mit dem Gehäuse verbundenen Dämpfungsscheibe eine Spannung induziert. Durch sie werden in Abhängigkeit der elektrischen Leitfähigkeit entsprechende Wirbelströme hervorgerufen. Diese wiederum verursachen magnetische Felder, welche ihrer Ursache, der Schwingung, entgegen wirken. Die daraus resultierende Dämpfung kann durch die Betrachtung der magnetischen Kräfte oder aber den Energieerhaltungssatz beschrieben werden. Um eine bessere Wirkung zu erzielen, wurden Magnete in alternierender Polarisation angeordnet. Dadurch wurde die Änderung der Durchflutung der Dämpfungsscheibe pro Periode erhöht. Mit Hilfe eines Fall-Testes wird die Abhängigkeit der Dämpfungswirkung von der Anzahl der Magnetpole dargestellt. Für die Ausprägung nennenswerter Wirbelströme ist die Beschaffenheit der Scheibe von entscheidender Bedeutung. Sie muss möglichst gut elektrisch leitend sein und darf dabei keine ferromagnetischen Eigenschaften besitzen. Mit Hilfe eines Versuchslagers wurden die Zusammenhänge von Dicke und Material der Scheibe sowie der Abklingzeit einer angeregten Schwingung untersucht.
BibTeX:
@inproceedings{WMLT8_10,
  author = {J. Rudolph and P.-K. Budig and R. Werner},
  title = {Theoretische und praktische Betrachtungen zur Schwingungsdämpfung in permanentmagnetisch gelagerten Systemen},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_10.pdf}
}
2011 Paditz, M. Dimensionierung von Magnetlagern: Am Beispiel der Versuchsstandsmagnetlager für das IPM Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Abstract is not available
BibTeX:
@inproceedings{WMLT8_11,
  author = {M. Paditz},
  title = {Dimensionierung von Magnetlagern: Am Beispiel der Versuchsstandsmagnetlager für das IPM},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_11.pdf}
}
2011 Budig, P.-K. Betrachtungen zur Theorie und Anwendung magnetischer Lager Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Es wird eine Einführung in einige theoretische Grundlagen magnetischer Lager gegeben wie: Verluste, Dynamisches Betriebsverhalten, Ausführungsformen magnetischer Lager. Einige Anwendungen werden beschrieben, wie: Drehmomenten Messgerät für 140000 min-1, Ventilator Teststand, Kühlwasserpumpe in einem Kraftwerk, Lager für extrem große Lagerkräfte im Bereich der Lagerkräfte von 16000 bis 50000 Newton, Schwungradspeicher im Hochvakuum mit 45000 min-1 mit permanentmagnetischen Radiallagern.
BibTeX:
@inproceedings{WMLT8_12,
  author = {P.-K. Budig},
  title = {Betrachtungen zur Theorie und Anwendung magnetischer Lager },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_12.pdf}
}
2011 Dohnal, F. Increasing the external damping of a flexible rotor by periodic control Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: The influence of a periodic open-loop control operated in parallel to an existing closed-loop PID control is investigated on a rotor system supported by two radial active magnetic bearings. The transient behaviour of the rotor is studied numerically and first experimental results are shown to demonstrate the applicability of the method. It is highlighted that by tuning the periodic control properly it is possible to amplify artificially the external damping of the rotor system. This concept allows increasing the total external damping well beyond the stability margin of the closed-loop control cycle.
BibTeX:
@inproceedings{WMLT8_13,
  author = {F. Dohnal},
  title = {Increasing the external damping of a flexible rotor by periodic control },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_13.pdf}
}
2011 Katzschmann, M., Karolewski, D. and Schäffel, C. Entwicklung eines magnetisch geführten, planaren Direktantriebs Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Der Beitrag stellt ein magnetisches 6D Positioniersystem vor, welches auf einem an der IMMS GmbH entwickelten, planaren 3DDirektantriebssystem aufbaut. Die bisher eingesetzten Luftführungselemente werden im 6DSystem durch eine geregelte, aktive magnetische Führung ersetzt. Dies erfordert zusätzliche Sensorik zum Erfassen der vertikalen Lage. Zusätzliche Aktoren (Spulen) sind jedoch nicht nötig, da mit den bereits vorhandenen 6 Spulen alle Freiheitsgrade im gesamten Fahrbereich kontrolliert werden können. Um den Prozess der Auslegung einzelner Komponenten und der mechanischen Konstruktion optimal zu gestalten, sind umfangreiche Simulationen notwendig. Auf Basis der Simulationsergebnisse entsteht ein System, das die Vorteile des ursprünglichen, direktangetriebenen, planaren Positioniersystems mit denen eines magnetisch geführten Systems vereint.
BibTeX:
@inproceedings{WMLT8_14,
  author = {M. Katzschmann and D. Karolewski and C. Schäffel},
  title = {Entwicklung eines magnetisch geführten, planaren Direktantriebs},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_14.pdf}
}
2011 Bräuer, P., Bartscht, M. and Werner, R. Reduzierung des Bauraums bei einem aktiven dreipoligen Radialmagnetlager unter Verwendung von siebgedruckten Wicklungen Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Der nachhaltige Umgang mit der zur Verfügung stehenden Energie und Ressourcen wird in Zukunft einen immer höheren Stellenwert erlangen. Dabei werden Magnetlager eine zunehmende Rolle spielen. Sie arbeiten berührungsfrei und damit schmiermittelfrei, wodurch sie in Umgebungen, in denen es auf höchste Reinheit ankommt, eingesetzt werden können. Der Wartungsaufwand ist durch fehlenden mechanischen Abrieb reduziert und die Lebensdauer dadurch erhöht. Die Betriebskosten sind darüber hinaus geringer, da die auftretenden Verluste gerade im Bereich hoher Drehzahlen 1/5 bis 1/20 derer konventioneller Lager betragen. Es haben sich drei verschiedene Bauformen für magnetische Lager herauskristallisiert, welche sich in ihrem Aufbau, Verlusten, Einsatzmöglichkeiten oder auch ihrer Regelbarkeit unterscheiden. Der vom Aufbau her einfachste Typ ist das Unipolarmagnetlager. In diesem Beitrag soll dafür die Bauraumreduzierung im Bereich der Wicklung durch den Einsatz siebgedruckter Leiter, wie sie bereits seit längerem für Kleinantriebe in der wissenschaftlichen Diskussion sind [1], [2], untersucht werden. Das Siebdruckverfahren erlaubt es, besonders dünne flächige Leiter herzustellen, die aufgrund des Verhältnisses zwischen Querschnittsfläche und Oberfläche ein besseres Wäremeabgabevermögen aufweisen als Runddraht und daher Stromdichten von bis zu 100A/mm2 zulassen. Ziel ist es, bei gleicher Lagerkraft und gleichem Rotordurchmesser das Bauvolumen und damit die Masse des Lagers signifikant zu reduzieren. Erste Berechnungen zeigen, dass eine Reduzierung des Volumens um bis zu 50% denkbar ist. Technisch möglich ist darüber hinaus auch eine Integration von mittels Siebdruck hergestellten Sensoren zur Lagemesseung. Besonders günstig erscheinen in diesem Zusammenhang kapazitive Lagesensoren. Als Ergebnis sollen konstruktive Vorschläge für den Bau magnetischer Lager mit siebgedruckten Wicklungen gemacht werden.
BibTeX:
@inproceedings{WMLT8_15,
  author = {P. Bräuer and M. Bartscht and R. Werner},
  title = {Reduzierung des Bauraums bei einem aktiven dreipoligen Radialmagnetlager unter Verwendung von siebgedruckten Wicklungen },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_15.pdf}
}
2011 Hübner, N. Dimensionierung von hochtourigen Magnetlagern am Beispiel einer Magnetlagerspindel für 140.000 U/min Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Am Beispiel der Auslegung einer Magnetlager-spindel für 140.000 U/min sollen die Besonder-heiten bei der Dimensionierung hochtouriger Antriebe dargestellt werden. So ist es unerlässlich, dass neben der Festig-keitsauslegung auch besonderes Augenmerk auf die Rotordynamik gelegt wird. Dies bedingt, dass bezüglich des Wellenaufbaus der Spagat zwischen dem Platzbedarf der einzelnen auf der Welle befindlichen Komponenten und dem zum unterkritischen Betrieb zwingend nötige, biege-steife Aufbau umgesetzt wird. Es wird gezeigt durch welche Maßnahmen dies realisiert werden kann und wie die für den Be-trieb zwingend benötigten Komponenten wie Messsystem, Motor- und Lagerkomponenten sehr kompakt aufgebaut werden können. Hierzu musste zum Teil auf bisher für Magnetlager eher unkonventionelle Werkstoffe und Aufbauten zurückgegriffen werden. Ein weiteres Problem stellt die möglichst ver-koppelungsfreie Anbindung des Prüflings an die Magnetlagerspindel dar. Ebenfalls nicht unwesentlich sind die im Betrieb auftretenden Verluste durch Luftreibung und Ummagnetisierung. Diese Verluste werden vom Antriebsmotor gedeckt und müssen durch eine geeignete Kühlung abgeführt werden. Hierfür wurde auf eine kostengünstige Wasser-kühlung zurückgegriffen, welche eigentlich für die PC Kühlung vorgesehen ist. Die vorhandene Realisierung und die Leistungsfähigkeit dieser PC - Flüssigkühler wird in diesen Beitrag kurz erläutert.
BibTeX:
@inproceedings{WMLT8_2,
  author = {N. Hübner},
  title = {Dimensionierung von hochtourigen Magnetlagern am Beispiel einer Magnetlagerspindel für 140.000 U/min},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_2.pdf}
}
2011 Hübner, N. and Paditz, M. Erfahrungen bei der Anwendung passiver Radialmagnetlager in einem Schwungradenergiespeicher Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Von EAAT wurde ein magnetisch gelagertes Schwungradenergiespeichersystem entwickelt. Die Schwungradwelle läuft dabei im Vakuum. Um die zur Lagerung erforderliche Leistung gering zu halten, wurden passive, d.h. permanentmagnetische Radiallager eingesetzt. Die axiale magnetische Lagerung wurde durch ein aktives (elektromagnetisches) Axiallager realisiert. In diesem Beitrag soll auf den Aufbau des Systems und die Erfahrungen im Einsatz des Systems eingegangen werden. Einen Schwerpunkt bilden dabei die Verluste im System, sowie deren Abhängigkeiten von z.B. Temperatur und Rotordynamik.
BibTeX:
@inproceedings{WMLT8_3,
  author = {N. Hübner and M. Paditz},
  title = {Erfahrungen bei der Anwendung passiver Radialmagnetlager in einem Schwungradenergiespeicher},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_3.pdf}
}
2011 Neumann, H. and Worlitz, F. Modellierung und Simulation eines Kalman-Filters für aktive Magnetlager Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Die berührungsfreie magnetische Lagerung eines Rotors erfordert hinreichend schnelle und hochgenaue Reglereingriffe. Durch die räumlich getrennte Anordnung von Sensor und Sensorelektronik sind Störungen des analogen Messsignales in Form von Rauschen nicht zu vermeiden. Daher ist eine Signalfilterung notwendig. Diese wird im einfachsten Fall durch einen Butterworth-Filter realisiert. Eine weitere Möglichkeit ist die Verwendung eines Kalman- Filters, welcher neben der reinen Signalfilterung außerdem die Schätzung innerer, nicht messbarer Systemzustände ermöglicht.
BibTeX:
@inproceedings{WMLT8_4,
  author = {H. Neumann and F. Worlitz},
  title = {Modellierung und Simulation eines Kalman-Filters für aktive Magnetlager },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_4.pdf}
}
2011 Düsterhaupt, S. and Worlitz, F. Modellierung und Simulation der Zuverlässigkeit magnetgelagerter Maschinen Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Der Einsatz aktiver Magnetlager in Turbomaschinen der Kraftwerkstechnik ist durch extreme Prozessund Umgebungsbedingungen gekennzeichnet. Fertigungstoleranzen und der Einfluss spezifischer Betriebs- und Störszenarien auf die Komponenten eines Magnetlagerregelkreises führen zu Parameterstreuungen. Die Folge ist eine last- bzw. arbeitspunktabhängige Zuverlässigkeit der Lagerkomponenten. Die Auslegung aktiver Magnetlager soll um die Zuverlässigkeitsanalyse unter Berücksichtigung von komponentenspezifischen Nichtlinearitäten erweitert werden. Dabei werden mit Hilfe geeigneter Methoden im Gegensatz zur diskreten Herangehensweise die spezifischen Lagerparameter unscharf betrachtet. Mit Hilfe der Monte-Carlo-Simulation werden Teilversagenswahrscheinlichkeiten der Komponenten durch Abtastung des Zustandsraumes ermittelt und unter Anwendung der Fehlerbaumanalyse zu einer Versagenswahrscheinlichkeit des Gesamtsystems zusammengefasst. Es wird im Auslegungsprozess ermittelt, welche Komponenten des Regelkreises redundant/diversitär ausgeführt werden müssen.
BibTeX:
@inproceedings{WMLT8_5,
  author = {S. Düsterhaupt and F. Worlitz},
  title = {Modellierung und Simulation der Zuverlässigkeit magnetgelagerter Maschinen },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_5.pdf}
}
2011 Rothe, R. and Töpfer, H. Entwicklung einer Leistungselektronik für den Betrieb von Magnetlagern Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Im Rahmen der Zusammenarbeit mit der Hochschule Zittau Görlitz / IPM und Innotas Elektronik wurde eine Steuerelektronik speziell für den Betrieb von Magnetlagern entwickelt. Ausgehend von den bisherigen Erfahrungen entstand ein Konzept für eine Elektronik, bei der neue Schaltungstechniken zur Anwendung kamen. Dieses wurde schrittweise umgesetzt und es entstanden die Baugruppen Controllerboard, Leistungssteller in Form einer PWM Endstufe und Stromversorgung. Es wurde eine komplette Einheit, bestehend aus 2 Controllerboards und 7 Leistungsstellern, für einen Versuchsstand am IPM aufgebaut.
BibTeX:
@inproceedings{WMLT8_6,
  author = {R. Rothe and H. Töpfer},
  title = {Entwicklung einer Leistungselektronik für den Betrieb von Magnetlagern },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_6.pdf}
}
2011 Weidenmüller, F. and Lehmann, R. Digitale Magnetlagerregelung Mathematische Grundlagen, Aufbau des digitalen Reglers und praktische Erfahrungen Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Magnetische Lager sind strukturinstabil. Sie benötigen in mindestens einer Achse eine aktive Lagerstelle. Es sind analoge oder digitale Regler notwendig, den Rotor in seiner Position zu halten. Der erste Teil des Beitrags beschäftigt sich mit den mathematischen Grundlagen der Magnetlagerregelung. Ausgehend aus dem Blockschaltbild sowie den Filter- und Reglergleichungen in der Laplace Ebene erfolgt die Herleitung der Gleichungen in zeitdiskreter Form. Die dafür notwendigen Gleichungen werden aufgestellt und in die Struktur des allgemeinen IIR-Filters überführt. Anschließend folgt die Transformation vom statorfesten in das rotorfeste Koordinatensystem für die 3-phasige Maschine. Ein struktureller Ablaufplan des Programms soll die Möglichkeit der speicheroptimierten Implementierung in den Prozessrechner zeigen. Der zweite Teil des Beitrags beginnt mit Erfahrungen im praktischen Aufbau einzelner Komponenten und endet mit Hinweisen zur Inbetriebnahme sowie einer Gegenüberstellung von Vor- bzw. Nachteilen analoger und digitaler Regler.
BibTeX:
@inproceedings{WMLT8_7,
  author = {F. Weidenmüller and R. Lehmann},
  title = {Digitale Magnetlagerregelung Mathematische Grundlagen, Aufbau des digitalen Reglers und praktische Erfahrungen},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_7.pdf}
}
2011 Rottenbach, T. and Worlitz, F. Revision der magnetgelagerten Pumpe nach Langzeiteinsatz im Braunkohlenkraftwerk Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Im Rahmen eines Forschungsprojektes wurde eine konventionell gelagerte Kühlwasserdruckerhöhungspumpe auf vollständig aktive Magnetlagerung umgerüstet und im Zwischenkühlkreislauf eines 500-MW-Kraftwerksblockes als Demonst-rationsanlage eingebaut und getestet. Ziel war es, die Eignung von Magnetlagern für den Einsatz an Turbomaschinen im Kraftwerksbetrieb nachzuweisen [1]. Im Anschluss an die Inbetriebnahmephase erfolgte der Langzeiteinsatz als Betriebspumpe [2]. Nach einer ca. dreieinhalbjährigen Laufzeit wurde die Pumpe einer Revision unterzogen. Dabei wurde der Zustand der Pumpe und speziell der Lagerkomponenten begutachtet. Erforderliche, zustandsabhängig durchzuführende Reparatur- und Wartungsarbeiten der Magnet- und Fanglagerkomponenten sollten den Weiterbetrieb der Pumpe im Kraftwerk sicherstellen. Aus festgestellten Mängeln an Einzelkomponenten sowie aufgetretenen Schwierigkeiten bei der Demontage z. B. infolge Korrosion waren Maßnahmen zu deren Vermeidung abzuleiten. Zudem lassen sich daraus Rückschlüsse für die konstruktive Gestaltung künftiger Anwendungen, einzusetzender Materialien und Anforderungen z. B. an die Wellendichtung ziehen. Der Beitrag gibt einen Einblick in die Erfahrungen und den Wissenszuwachs, die während der Revision der aktiv magnetgelagerten Pumpe gesammelt wurden.
BibTeX:
@inproceedings{WMLT8_8,
  author = {T. Rottenbach and F. Worlitz},
  title = {Revision der magnetgelagerten Pumpe nach Langzeiteinsatz im Braunkohlenkraftwerk},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {http://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_8.pdf}
}
2011 Fleischer, E. and Hofmann, W. Auslegung eines Asynchronversuchsmotors mit Massivläufer für ein Hochgeschwindigkeitsmagnetla