In order to reduce the torque ripple and suspended force ripple of the single winding BPMSM, a rotor structure with tile-type eccentric magnetic poles is proposed. Firstly, the expression of air-gap flux density of eccentric magnetic pole is deduced, the influence of important parameters of the structure on air-gap flux density is analyzed, and the mathematical model of the motor's suspended force is established. Secondly, based on the finite element analysis, the multi-objective genetic algorithm is used for optimization, and the structural parameters of the tile-type eccentric magnetic pole are designed with the torque ripple and the suspended force ripple as the optimization goals. Finally, the optimized eccentric magnetic pole and the equal-thickness magnetic pole are compared and analyzed. The results show that the optimized motor has significantly reduced torque ripple and suspension force ripple on the basis of ensuring the output capacity of the motor.

Eccentric pole,Single Winding Bearingless Permanent Magnet Synchronous Motor,Optimized design,Multi-objective genetic algorithm,Suspended ripple,Torque ripple