Rotor Surface Optimization of Interior Permanent Magnet Synchronous Motors to Reduce both Rotor Core Loss and Torque Ripples

This paper describes rotor shape optimization of interior permanent magnet synchronous motors to reduce both rotor core loss and torque ripples. From the observation of the core loss distribution obtained by the finite element analysis, the rotor surface shape is selected as design variables and automatic optimizations are carried out. The experimental verification by the prototype machines is also carried out to confirm the validity of the optimization. It is clarified that both the rotor core loss and the torque ripples can be significantly reduced by optimizing the rotor surface.