Rotor Skewed Pole Analysis of Permanent Magnet Synchronous Motor Based on Energy Method and Fourier Series Analysis

Aiming at the cogging torque of permanent magnet synchronous motor (PMSM), a method for expressing the cogging torque under the condition of rotor skewed pole of PMSM based on energy method and Fourier series analysis is proposed. The mathematical model between the cogging torque and the rotor skewed pole angle is established. Based on this, the optimal skew pole angle corresponding to the minimum cogging torque under continuous skewed pole and segmented skewed pole is derived. Based on this mathematical model, the output torque expression of PMSM under segmented skewed pole is further obtained. The simulation results prove that the cogging torque is weakened by 63.7 %, the cogging torque is weakened by 81.6 %, the waveform of the back-EMF is optimized and improved, and the high-order harmonic amplitude is effectively weakened, and the THD of back-EMF is reduced by 66.3 %.