Drive configurations for fully-pitched winding switched reluctance machines

Switched reluctance machines with fully-pitched windings have been shown to make very efficient use of these windings, and prototype machines have been shown to produce over 30% more torque than conventional SRM designs. 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 the operation of a working drive, and examines the volt-ampere requirements of the power converter. It is shown that with standard power converters, commutation is not a problem, but that power device losses are increased. The reason for this is explained and a new power converter topology is introduced which almost entirely overcomes the problem. Thus it is demonstrated that switched reluctance machines with fully-pitched windings do not require a larger power converter.