Optimum Pole Number Combination for High-Speed High-Power BPM Bearingless Motor

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.