A Novel Compound Hybrid Flux Machine Towards Electric Vehicle Traction

It is recognized that there is a recent need for direct-drive machines in electric traction systems. The transverse-flux machine (TFM) is an excellent candidate for electric vehicle (EV) traction due to its short effective flux path and high torque density. Yet, TFMs typically suffer from a large longitudinal size and face difficulty arranging toroidal coils for ordinary inner-rotor machines. Thus, this study proposes a novel compound double-stator hybrid flux machine (CDS-HFM) topology in order to create more compact and powerful EV drives. In the CDS-HFM, the poly phases are distributed along the circumferential direction with end regions physically isolated. Normal toroidal coils are improved as concentrated coils. The CDS-HFM combines the transverse and modulated flux from permanent magnet vernier machine. Its operational principle is introduced and analyzed by a separate flux path modeling method. The effectiveness of this idea was verified through quantitative performance evaluation using 3-D finite element analysis.