Abstract: In order to further improve the sinusoidal nature of the air-gap magnetism waveform of eccentric magnetic pole Permanent Magnet Synchronous Motor (PMSM) and enhance the efficiency of motor optimization design, an optimization design method based on analytical calculation and GA is proposed for the eccentric pole of PMSM. Firstly, considering the effects of tooth-tip saturation, stator slotting, pole-to-pole leakage and edge effect and magnetic circuit saturation on the air-gap flux density, the analytical calculation model of air-gap flux density under parallel and radial magnetization of eccentric poles to satisfy the subsequent optimization calculations is deduced, respectively. Then, the pole structure parameters of this model are optimized by GA. Finally, the accuracy of analytical calculation and optimization results are compared and verified by finite element simulation. The results show that the analytical calculation model obtained under this method has high accuracy, the sinusoidal nature of the air-gap magnetic density waveforms of the motor optimized for both parallel and radial magnetizing poles is improved, the cogging torque is reduced, and the efficiency of the optimized design is improved.

Key words: Permanent Magnet Synchronous Motor(PMSM), air-gap flux density, eccentric magnetic pole, analytical calculation, Genetic Algorithm(GA)