Design and performance of a high efficiency 5-phase switched reluctance motor

This paper describes the electromagnetic design, construction and testing of a prototype 5-phase switched reluctance motor that exploits the short flux path concept. If the phase windings are arranged so that neighbouring poles have opposite magnetic polarity then the B-field associated with any two consecutive phase windings forms a short flux loop linking adjacent excited stator poles via the rotor teeth. The MMF required to produce a given flux in the airgap is reduced, resulting in a drop in copper losses. Furthermore, the volume of iron in which hysteresis and eddy current losses are generated is reduced, thus resulting in a drop in iron losses. This paper reviews aspects of the 5-phase motor design, dynamic simulation and construction. Test results from a prototype drive rated at over 4 kW are given.