Switched reluctance motor with magnetic slot wedges for automotive traction application

The switched reluctance motor (SRM) is very attractive because of its many advantages especially in electric vehicle (EV). However, it presents two major drawbacks: torque ripples and stator vibrations. These phenomena are the cause of a disturbing noise. In order to reduce the torque ripples and the radial force (main cause of the stator vibrations), one solution is to add magnetic slot wedges. In this paper, a SRM with wedges is compared to the conventional one including some static and dynamic features. First, field lines, magnetization curves and static torques are discussed. Secondly, torque-speed curves, harmonic analyzes and cartographies with minimum ripples are compared. The last includes several operating points (speed-torque) in steady state.