Abstract
One of the major problems associated with interior permanent magnet machines is torque ripple, a problem that causes undesirable noise and possibly speed ripples. In this paper, rotor shaping near q-axis and its effects for torque ripple reduction are analyzed. Two new design variables are introduced for shaping the rotor pole. To verify the trade-off relationship between average torque and torque ripple by rotor pole shaping, the multi-objective optimization algorithm is employed to search the Pareto front of the problems. All results are obtained from 2D finite element analysis. The simulation results on two different lead angles are compared and the effect of rotor pole shaping is observed.