Optimization of Magnet Shape Based on Efficiency Map of IPMSM for EVs

A study on optimization exemplary for permanent magnet V straight shape of rotor in interior permanent magnet synchronous motor (IPMSM) is presented, aiming to achieve higher efficiency map in the operating duty cycle US06. The reduction of PM material is valuable as the cost of rare earth is increasing. The finite element analysis (FEA) is used to simulate d- and q-axis inductance, develop the efficiency map at the speed of 4500 and 9000 rpm, and analyze the energy loss. The optimal design process is introduced to reduce magnet material based on the efficiency map of IPMSM produced using FEA. This study has resulted in 20% reduction of magnet size, comparing with the original designs. The FEA result is confirmed by the tests of the prototype machine. As a result, the high-efficiency IPMSM optimizing process is concluded for electric vehicles as providing some reference in the future work.