Electromagnetic Force Waves Reduction of Surface-mounted Permanent Magnet Synchronous Motors Based on Segmented Magnetic Poles with Different Combinations of Pole-arc Coefficients

The calculation and weakening of electromagnetic force waves are especially critical in the design stage of the motors. Considering the effects of complex slot structure, the radial electromagnetic force waves of 6p36s surface-mounted permanent magnet synchronous motor (SPMSM) are analyzed and calculated based on the fast and accurate calculation method and verified by finite element method (FEM). Furthermore, the segmented magnetic poles with different combinations of pole-arc coefficients are designed to weaken radial electromagnetic force waves, and the optimal number of axial segments and combination of pole-arc coefficients are summarized. Finally, the electromagnetic force waves of four SPMSMs with different slot-pole combinations including 6p36s, 6p9s, 8p12s, and 10p12s are analyzed by FEM to verify the universality of the conclusions. The results indicate that the number of axial segments should be an even number and selecting the combinations of pole-arc coefficients determined based on the general method proposed in this paper can weaken the electromagnetic force waves of specific order.