Evaluation of Switching Ripple Effect on Efficiency of Novel Spoke-Type IPMSM Using Dy-Free Magnet-Comparison to IPMSM using NbFeB Magnet

This research aims to develop a low-cost, high-efficiency traction motor. A novel spoke-type interior permanent magnet synchronous motor (IPMSM) is proposed and evaluated in detail. Although the proposed IPMSM uses a Dy-free magnet and a ferrite magnet, the same torque can be obtained as the IPMSM mounted on TOYOTA Prius 4th generation. Therefore, the proposed IPMSM contributes to reducing the magnet cost. In this paper, the proposed IPMSM was evaluated in detail considering the switching ripple caused by the inverter and compared with Prius’s IPMSM. As a result of simulation, the proposed IPMSM has higher efficiency than that of the Prius’s IPMSM at frequently used operating points under realistic low switching frequency.