Power converter circuit for a switched reluctance motor using a flyback transformer

A power-converter circuit for a switched reluctance motor is proposed. It consists of one switching device per phase and a dump capacitor, auxiliary switch and flyback transformer. In this converter circuit, the demagnetising current of an off-going phase is stored in the dump capacitor and is returned to the DC link capacitor through the transformer. The dump capacitor voltage can be controlled by the duty ratio control of the auxiliary switch. The auxiliary switch is PWM-controlled in high frequency, so that the size of the transformer can be reduced. The voltage rating of the auxiliary switch and dump capacitor is lower than that of the main switches and DC link capacitor. The modes of operation are described and the effectiveness of the proposed converter circuit is verified through simulation and experiment.