Drive configurations for fully-pitched winding switched reluctance machines

Switched reluctance machines with fully-pitched winding have been shown to make very efficient use of the winding, and prototypes machines have been shown to produce over 30% more torque than conventional SRMs. There has been some suggestion that the mutual coupling between phases makes commutation more difficult and that a larger power converter is required. This paper shows operation of a working drive, and examines the volt-ampere requirements of the converter. It will be shown that with standard converters commutation is not a problem, but that power device losses are increased. The reason for this is explained and a new converter topology introduced which almost entirely overcomes the problem. Thus it is demonstrated that switched reluctance machines with fully-pitched winding do not require a larger power converter.