Flux-switching permanent magnet machine drive system for plug-in hybrid electrical vehicle

Plug-in hybrid electric vehicle (PHEV) depends mostly on the electric drive system where the internal combustion engine just acts as the auxiliary unit, which has strict constraints for the drive machine. According to the Toyota Prius configuration, one novel PHEV drive system in this paper has been brought forward which primarily includes one drive machine operating as both motor and generator, energy storage unit combining supercapacitor and battery. In the novel PHEV, the ideal tendency is to use the drive machine over the entire torque/speed range, including starting/acceleration, high speed cruising, regenerative braking, etc. The flux-switching permanent magnet machine (FSPMM) for the drive system has been studied in details. Firstly, the structure and operation principle are analyzed theoretically. In order to achieve higher torque/power density and lower torque ripple, FSPMM with 6/7 (stator/rotor) poles and 12/14 poles according to plenty of investigations are optimized based on our setting objective function decided by actual projects. Moreover, it analyzes several typical performance curves, such as cogging/rating torque, flux linkage, back-EMF, and self-/mutual-inductances. Finally the flux-weakening ability and efficiency are estimated by experience. The results indicate that FSPMM is one ideal candidate for our PHEV drive system for its strong thermal dissipation ability, good mechanical robustness, strong flux-weakening ability, etc.