Studies of high-efficiency electrical steels used in electric vehicle motors

Application of permanent magnet synchronous motor (PMSM) has been increasingly popular in electric vehicle (EV) area since cost-effective electrical steels were recently discovered. This paper mainly presents the performance and characteristics of EV motors using varieties of high-efficiency electrical steels. At first, the electro-magnetic and mechanical properties of electrical steels are described. Low loss, high induction and excellent mechanical strength are critical criteria to evaluate the electrical steel. However, the gage of electrical steel is a crucial factor to affect the properties. Secondly, the basic principle and algorithm for calculation of efficiency of an EV motor are explained. Finally, the modeling and experimental results for different gages of electrical steel sheets used in EV motors are analyzed.