Multipolar High-Speed IPMSM Design for EV Traction Considering Mechanical Stress

The greenhouse effect is getting worse in these days. To reduce this environmental problem, emission regulation in the automotive industries became strict. Accordingly, the automotive makers started to develop the environmental friendly vehicles such as the hybrid electric vehicle (HEV) and electric vehicle (EV). In the x-EV system, electric traction motor is the most important part act as the engine of the conventional vehicle. The design trend of the electric motor for EV traction is the high-speed low-torque with the reduction gear. For this reason, high speed operating condition should be considered in the design process. In this paper, some design factor study was done, considering both the electrical performance and the mechanical stress. Using these study results and response surface method (RSM) optimum design was conducted. From the optimum designed motor, mechanical stress simulation was done considering about the 15% margin of the maximum operating speed of the electric motor. Consequently, the multi-layered interior permanent magnet motor (IPMSM) design was done fulfill the electrical performance and the not exceeding the yield strength of the electrical steel sheet consist the electrical motor.