Modeling of Axial Flux Permanent Magnet Motors by a Finite Element Ap-proach-Application to In-wheel Motorcycles

Abstract

Axial flux permanent magnet motors have been applied for many electric vehicles due to the high torque and power densities, compact sizes, and multipolar disc-type structure. In this paper, the axial flux permanent magnet motor with the concentrated winding, and axial flux-segmental rotor is presented and compared with a conventional BLDC motor. The proposed topology consists of permanent magnet segments and a slotted stator. The comparison with the existing BLDC motors, the proposed machine contains the reduced amount of permanent magnets and being easy to scale up power and torque. This approach makes the assembly easier and reduce the cost compared to conventional motors. Moreover, the multi sector-proposed topologies have the higher torque density and torque-to-weight ratio compared to reported the axial flux switch reluctance motors. The detailed design and operation of the proposed machine are presented, and the performance is also evaluated for an in-wheel traction application. Especially, for a multipolar disc-type structure, the axial flux permanent magnet motors is easy to scale up power for the next models.