Electromagnetic Analysis of Compound Excitation High Speed Permanent Magnet Synchronous Motor

To suppress the rotor eddy current loss of the conventional high speed permanent magnet synchronous motor (HSPMSM), a compound excitation HSPMSM (CEHSPMSM) excited by both rare earth permanent magnet and ferrite permanent magnet on rotor is proposed in this paper. Firstly, the new compound rotor structure is introduced and its equivalent magnetic circuit model (EMCM) is established. And then the magnetic fields are analyzed and an in-depth study of eddy current losses are calculated by finite element method (FEM) in detail. Finally, a CEHSPMSM and a conventional HSPMSM constrained with the same stator structure and effective volume are designed for performance comparison and analysis. The results show that the CEHSPMSM can effectively reduce rotor eddy current loss without decreasing the motor performance compared with that of the conventional HSPMSM.