Design and realization of a digital control system for a 4 kW bearingless permanent magnet slice motor

Bearingless permanent magnet slice motors have a wide range of applications in the area of special electric drives. In this paper, a 3-phase permanent magnet slice motor with the power around 4 kW is set up, and a system of bearingless permanent magnet slice motor is introduced. Theoretical formulas of driving system and radial suspension forces are given, and then the control system for the 3-phase bearingless permanent magnet slice motor is designed and presented. An experimental platform of digital control system with TMS320F240 DSP controller is designed to meet the need, and experiments including speed regulation and suspension force control are performed. The waveforms of the displacements are presented under unload and load. It has shown that the vibration amplitude in x and y direction is less than 500 mum under unload and load, while rotor speed are changed from 0 r/min to 7700 r/min