New Approach For A Bearingless Three-Phase Induction Machine With Divided Winding

This paper shows a new approach for a bearingless three-phase induction machine with divided winding. The studies of this machine have evolved significantly, providing a more efficient and compact system. The constructed machine is a four pole 0.25 kW bearingless induction motor. For the system control the DSP (Digital Signal Processor) device is used. The radial positioning is accomplished through the forces control generated by the internal machine fields. The rotor windings were developed to operate with minimum induced currents and to facilitate the electric torque decoupling in relation to the radial positioning control. The system control is a program written in an ANSI C standard language, where two digital PID (Proportional-Integrative-Derivative) controllers are implemented for the radial positioning and six Proportional controllers for the current control. The system uses a state observer for the speed control by PID controller. The used DSP resources are the A/D input channels for the voltages and currents reading, the PWM outputs for the inverters control, the serial RS-232 interface and parallel ports for communication with the PC.