A Novel Spoke Type Interior PM Rotor Structure for a 9-Phase Unbalanced and Asymmetric Winding Motor

In this paper, a novel flux-assisted spoke type permanent magnet synchronous motor with an unconventional 9-phase stator structure is presented. The proposed 9-phase motor has two additional flux-assisted magnets between the main spoke magnets. Initial design, detailed magnetic simulations, parametric analyses are completed. A comparison between the proposed motor and unconventional 9-phase surface magnet motor are also performed and the benefits of the novel 9-phase structure is presented. It is revealed that the novel 9-phase motor has certain benefits for applications requiring more power density and wide constant power region.