A modified C-dump converter for variable reluctance machines

A type of converter for variable reluctance machine (VRM) drives is described. In this converter topology the energy extracted from an offgoing phase is stored in a dump capacitor. The energy stored is consequently used to either quickly turn on the next ongoing phase or energize the conducting phase frequently during the conduction interval instead of being returned to the supply as for a conventional C-dump circuit. Since the additional switch used to pass the energy to the C-dump capacitor is switched under a relatively low voltage condition and its switching frequency is relatively low, the rating of the additional switch is modest.<>