Design and Analysis of a Novel Double-Stator Hybrid Flux Machine for Direct-Drive Electric Traction

The transverse-flux machine (TFM) is an ideal candidate for direct-drive traction due to its short effective flux path and high torque density. However, TFMs normally suffer from large longitudinal size, while the toroidal coils are hard to arrange for ordinary inner-runner machines. The configuration of phases leaves tricky in TFMs. To this end, this study sets out to propose a novel double-stator hybrid flux machine (DS-HFM) topology in order to make direct-drive machines more compact and powerful. In the DS-HFM, the poly phases are distributed along the circumferential direction with physical isolation end regions. Conventional toroidal coils are redesigned to concentrated coils. The operational principle is introduced and analyzed. Through 3-D finite element analysis, the quantitative performance evaluation verifies the effectiveness of this idea.