A novel C-dump inverter for reduction of negative torque due to mutual inductance of VRM

This study describes the influence of the mutual inductance between the adjacent phase windings of variable reluctance motor (VRM) and presents a new type of inverter for reduction of such influence. In this inverter topology, an additional power switch is used as compared with the conventional C-dump inverter circuit, hence unwanted negative torque produced by the mutual inductance in the winding next to the energizing phase is remarkably reduced. Such circuits result in an increase of the average torque and contribute to the improvement of overall drive efficiency. Theoretical prediction is verified by experimental results obtained with the integration of presented inverter and protype 6/4 VRM