Switched reluctance motor drives with fractionally-pitched winding design

A new topology of switched reluctance motor (SRM) drives with fractionally-pitched winding design is proposed in this paper. Compared to the conventional single-tooth winding SRM, this new drive offers higher torque density and better performance by utilizing the mutual-coupling among phase windings. While compared to SRMs with fully-pitched winding configuration, the proposed design possesses better current commutation capability due to the self-inductance variations, and hence is a better runner at high speeds. In this paper, a detailed analysis of the proposed motor drive is given, which includes motor and drive topologies, torque density comparison with conventional SRM and the proof of the theory by detailed magnetic field analysis and experimental work. The results of the study show that the proposed motor system is an attractive candidate for variable speed industrial applications.