Design optimization of single-phase outer-rotor hybrid excitation flux switching motor for electric vehicles

Nowadays, in-wheel motors applied in pure electric vehicles (EVs) propulsion systems have attracted great attention in advance research and development. In-wheel direct drive eliminates the mechanical transmission, differential gears and drive belts. Thus, in-wheel direct drive provides quick torque response, higher efficiency, weight reduction, and increased vehicle space. As one of alternative, a new design of hybrid excitation flux switching motor (ORHEFSM) for in-wheel drive EV is proposed. In this paper, the optimization design of single-phase 8S-4P outer rotor HEFSM is analysed. Open and close circuit of initial and final design is compared based on 2-D finite element analysis (FEA). The optimized design motor has produced higher torque which is 138.18Nm with 22.2% improvement compared to initial design motor which is 107.5Nm and has achieved the target value which 111Nm. The initial maximum power achieved was 17.02kW, while for the improved design motor, it has increased to 41.81kW, since the target maximum power is 41kW. The design optimization has been made on the initial design machine shows that there is great enhancement on torque and power.