Variable reluctance motor structures for low-speed operation

The static torque capability of three competing variable reluctance motors is compared in order to identify which structure is best suited for low-speed operation. Linear analysis is the basis of the comparison between a conventional switched reluctance motor, a variable reluctance motor with mutually coupled windings, and a variable reluctance motor with anisotropic rotor. End turn and multipole effects are considered. The impact of saturation is considered by comparing static torque computed with finite element models. This analysis provides the rationale for choosing one configuration over another under fixed voltage and current limit constraints. The alternative constructions are shown to have potential for significant improvement in static torque under certain conditions.