Sizing a switched reluctance motor for electric vehicles

This paper proposes a methodology to determine separately the peak and continuous power ratings of a switched reluctance motor (SRM) for electric propulsion of an electric vehicle (EV). The input data consist of the EV main specifications (e.g., rated and maximum velocities, vehicle mass, driving schedules). Estimation of the variations of the copper and core losses with vehicle speed and motor output power is necessary to calculate the continuous power rating. The loss variations are estimated by considering the SRM operation principles and assuming (if not known) loss values at only one operating point. Using the obtained expressions, the SRM efficiency contours can be then estimated before designing and building the SRM. The SRM thermal duty can be reduced by appropriate choice of the individual loss components in the design process.