Effect of different rotor configurations on torque characteristics of a 10-pole/12-slot flux switching permanent magnet machine

Flux switching permanent magnet machine (FSPM) is a new kind of doubly-salient PM brushless machine, which has high power density and simple structure. But the main problem of FSPM is the high cogging torque and torque ripple due to its unique structure, which causes larger vibration and noise. The electromagtic torque, cogging torque and torque ripple characteristics of FSPM were investigated, which is a 10-plole/12-slot motor for electric vehicle application. In addition to different winding structures, three novel rotor configurations were proposed to reduce cogging torque and torque ripple, namely, rotor with notched teeth, rotor with stepped teeth, and rotor with eccentric teeth. Their characteristics are simulated by finite-element analysis (FEA) and compared with FSPM which has conventional rotor teeth structure, the FEA results show that these novel rotor structures effectively reduce the cogging torque and torque ripple at only slight cost of average electromagnetic torque.