The use of three phase bridge inverters with switched reluctance drives

Switched reluctance motors are virtually always supplied with unipolar current pulses: this requirement is substantially different from all other AC motor drives, and has led to the development of alternative power electronic converter configurations. It is generally perceived that it is not sensible to operate an SRM from a standard three-phase converter. Such conclusions arise from the assumption that it is not possible to excite one phase at a time when operating from a three-phase bridge. This paper first explores the problems of using three-phase bridge power converters driving standard star and delta machine configurations. It then demonstrates how, with a minor modification, it is possible to operate an SRM with unipolar currents, fed from a conventional three-phase bridge. The new circuit configuration presented permits the use of standard power converters without any significant loss of performance.