Cogging torque reduction of flux-switching permanent magnet machines without skewing

The flux-switching permanent magnet (FSPM) machine exhibits competitive torque capability and power density due to the high flux density. As a penalty, the cogging torque is relative large, resulting in unfavorable torque pulsation. Due to the simple and robust rotor construction, additional dummy slots are adopted to reduce the cogging torque without skewing magnets or teeth. The optimal dimensions of the added dummy slots are performed by finite element analysis. The predicted results confirm the effectiveness and simplicity of the method. Moreover, the proposed methods can be applicable to other stator-PM brushless machines having similar rotor structure.