Synchronous Reluctance Machines: Theory, Design and the Potential Use in Traction Applications

The volatilities in the permanent magnet price have raised interest within the automotive industry for finding substitute electric machine designs. The proposed alternatives are synchronous reluctance machines (SyRM) and its derivatives, assisted synchronous reluctance (PMASR) machines. These solutions rely on high reluctance torque thus theoretically needing no magnet material in the rotor structure. This paper covers reluctance machine theoretical background, rotor parametrization, design alternatives, structural analysis, and optimization. Commercially available traction reluctance machines applications have been investigated. Marine and freight traction and commercial vehicle power take-off have been selected as application niches. Finally, a performance comparison for different saliency ratios of the ideal SyRM, ferrite and neodymium PMASR has been conducted.