A new excitation scheme for polyphase segmented switched reluctance motor

Use of in-wheel motors for lighter electric vehicles (EV) is widespread. Motors commonly used for this purpose are brushless DC motors (BLDC), because of high efficiency and power density. However, motors without permanent magnets are desirable due to lower initial cost and higher reliability. Switched reluctance motor (SRM), with simple and rugged construction, is an alternative. But, SRM has lower torque to weight ratio than BLDC. The torque to weight ratio is improved by using segmented SRM (SSRM). Also, torque to weight ratio increases with number of phases. It is shown in this paper that five phase SSRM has the highest torque per volume. A new excitation strategy for this motor to reduce torque ripple is proposed. With this excitation strategy, conventional VSI can be used instead of asymmetric bridge inverter. Five phase SSRM could be an alternative to BDLC for in-wheel EV application.