Reduction of Cogging Torque and Torque Ripple in Interior PM Machines With Asymmetrical V-Type Rotor Design

High cogging torque is a common drawback of the interior permanent magnet machine. In this paper, a novel technique is adopted to reduce cogging torque and torque ripple by using an asymmetrical V-type rotor configuration. First, the analysis modes are presented, and the proposed rotor is optimized by the hybrid design of experiment. A satisfactory set of parameters is determined. Next, the cogging torque and the torque ripple of the proposed model are compared with those of the basic model. The results demonstrate that the cogging torque and the torque ripple are reduced significantly by the adoption of the proposed rotor. Then, the performance of the proposed model rotating clockwise is compared that of the proposed model rotating counterclockwise to evaluate the effectiveness of the proposed rotor. Finally, the validity of the proposed method is confirmed by experiment.