Design and optimisation of an In-wheel switched reluctance motor for electric vehicles

To improve the mechanical performance of the In-wheel switched reluctance motor (SRM) used in electric vehicles (EVs), structure design and geometrical multi-objective optimisation strategy for the In-wheel SRM were developed in this study. The design method for major parameters of the In-wheel SRM was presented by means of design specifications of the EVs. According to requirements of the EVs, four indicators of the SRM were defined to evaluate the development of the SRM and perform the optimisation. To simultaneously improve the static performance of the SRM, a novel multi-objective simultaneous optimisation function was proposed by using four weighted factors and considering sensitivity analysis of the design variables on indicators. A four-phase 16/20 In-wheel SRM with an outer rotor was designed and optimised based on the proposed multi-objective optimisation method. The influence of design variables on average torque, torque ripple, efficiency, and torque density was analysed based on a combination of finite element analysis and orthogonal experiment design method. The static and dynamic torque performances of the optimised SRM were evaluated and compared with those of the initial motor. The comparison results showed that the proposed multi-objective simultaneous optimisation strategy can greatly improve the static and dynamic torque performances of the SRM.