Optimal shape design of rotor to reduce torque ripple for IPM motor based on the principle of mutual harmonics exclusion

In order to reduce the torque ripple in interior permanent magnet (IPM) machine and obtain the precise calculation result of torque ripple simultaneously, a 1.5 kW IPM synchronous AC motor model with optimized rotor topology is built. The revised analytical expression of ripple torque is proposed and the reduction method is analyzed theoretically. The one-layer V-shape rotor with 8 poles and 48 slots is selected as the best choice for the motor topology. The torque ripple is minimized by adjusting two key parameters of rotor and analytical calculation result of torque ripple for this model is worked out based on the principle of mutual harmonics exclusion. Finally, the finite-element results verify the veracity of the calculation result and the effectiveness of the proposed method.