Torque ripple reduction of interior permanent-magnet synchronous motor by pole-shoe shaping and skewing

This paper aims to analytically investigate the torque ripple producing mechanism of interior permanent-magnet synchronous motor considering stator slotting effect and rotor saliency. Based on this analysis, a combination of rotor-design technologies is used to suppress the torque ripple. Taguchi robust design based on orthogonal array is applied to obtain a not only optimal but also robust rotor design for minimizing torque ripple. Analytical results demonstrate that stator slotting and rotor saliency will lead to flux-path permeance fluctuations which are one of the main contributors to torque ripples in interior permanent-magnet synchronous motors.