Integration of Signal Processing Capability in an AMB Controller to Support Remote and Automated Commissioning

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.