Design and Analysis of Surface-Mounted-Type Variable Flux Permanent Magnet Motor for Wide-Speed Range Applications

This paper presents the design and analysis of surface-mounted-type variable flux permanent magnet (VFPM) machines for wide-speed range applications. The VFPM machines with a low-coercive-force (LCF) magnetic material have been studied extensively for their potential to improve the efficiency and extend the flux-weakening range of PM machines. In order to implement the design of the VFPM machines effectively, we perform a characteristic analysis of the LCF magnet with respect to design parameters. Subsequently, a dynamic characteristic analysis of VFPM machines is performed for decided design parameters. Finally, the analysis results of the designed VFPM machines are compared with measured results, and the validity of the design of the VFPM machines is confirmed.