Comparative study of novel variable-flux memory machines having stator permanent magnet topologies

Nowadays, numerous electrical machine topologies have been proposed and extensively investigated, which can extend the operating speed range together with the improvement of flux weakening capability without scarifying high efficiency. Amongst these machine topologies, variable-flux permanent magnet machines (VFPMs) are a competent candidate for electric vehicle/hybrid electric vehicle (EV/HEV) propulsion. This paper attempts to quantitatively compare two novel MMs having stator-PM configurations, which are derived from the SF and variable reluctance (VR) topologies, respectively. The machine topology, operating principle and design consideration will be addressed. Then their major electromagnetic performance will be analyzed and compared, which confirms the superiority of SF topology. A SFMM prototype is manufactured, and the experimental validation will be given in the full paper.