Reduction of permanent magnet eddy current loss in interior permanent magnet synchronous motor according to rotor design optimization

This study presents the optimized rotor shape of Interior Permanent Magnet Synchronous Motor (IPMSM) with the concentrated winding in order to reduce eddy current loss of Permanent Magnet (PM) and torque ripple under the running condition of Maximum Torque Per Ampere (MTPA) and flux weakening control. Particularly, PM eddy current loss, which is a distinctive loss component in IPMSM, has been numerically investigated with the 3-D Finite Element Analysis (FEA). Associated with the 3-D FEA, the optimal design has been carried out to determine the optimized rotor shape, which contributes to reduce PM eddy current loss and torque ripple without significantly sacrificing the rated torque. The characteristics of the optimally designed rotor shape are compared with the primitive one, manifesting the improved performance, and also thoroughly investigated on the mechanical safety.