Axial Flux Permanent Magnet Vernier Machine with Single-wound Dual-stator and Spoke Permanent Magnet Rotor for Electric Vehicle In-wheel Traction

In this paper, a dual-stator axial flux permanent magnet machine with a spoke-type rotor for electric vehicle applications is investigated. The rotor PMs are positioned in a spoke-type field-concentrating arrangement, which provides high flux concentration. Two stators-one stator configuration with double-layer wound coils and another without winding-are employed. The usage of single-layer wound coils is possible in this topology, and by using this type of winding it is possible to implement advanced in-slot cooling systems. Analytical and electromagnetic finite element analysis (FEA) studies considering its geometrical and electrical properties have been performed on this machine. The performance indices for the traction application based on the analytically calculated torque-speed characteristic, and FEA calculated torque versus torque angle have been assessed, and the results indicate that by using the proposed flux weakening methods, this machine can perform the flux weakening and operate in the constant power region of the torque-speed characteristic.