EV 구동용 WFSM의 최대 효율 제어를 통한 효율 개선

Abstract

This paper presents a control method in the main drive section to improve efficiency of Wound Field Synchronous Motor (WFSM) for electric vehicle (EV) traction. However EV is the environmentally-friendly and innovative, short mileage of the EV is a big problem. To overcome this weakness, the development for improving the efficiency of traction motor is in progress. The efficiency of motors can be enhanced using two methods, optimal shape design method and control method. Although optimal shape design method can improve the efficiency of traction motor, there is a limit in shape change of motor due to its restricted space. For this reason, it is essential to improve efficiency using the control method. This paper compares two methods for advanced efficiency, Maximum Torque Per Ampere (MTPA) control and maximum efficiency control method using efficiency map. As a result, maximum efficiency control method promotes the better efficiency of EV traction motor than MTPA control method, while satisfying the rated output of WFSM for EV traction in the main drive section. This paper especially shows enhancement of efficiency in low speed range.