Vibration Reduction by Grooving on Magnets for PMSMs

This paper proposes a design schem for grooved pole used in surface-mounted permanent magnet synchronous machines (PMSMs). This design effectively reduces pole-frequency vibration while maintaining torque performance. Firstly, the air-gap flux density and radial electromagnetic force are analytically calculated, clarifying the phase relationships of the radial electromagnetic forces with the same frequency and order. Based on this analysis, an optimized design schem for grooved pole is proposed. This design can alter the amplitude and phase of air-gap flux density harmonics, thereby reducing pole-frequency radial electromagnetic force and pole frequency vibration. A 10-pole 12-slot PMSM is used as an example for simulation, of which the results show that the proposed design effectively reduces pole-frequency vibration and torque ripple while maintaining torque density.