Optimal Design of Five-Phase PM Assisted-Synchronous Reluctance Motor based on Particle Swarm for Vehicle Traction Applications

High torque density, wide-constant power operating region, low torque ripple, wide speed range, and high efficiency are crucial requirements for an excellent electrical motor destined for vehicle traction applications. These traction performance parameters are greatly affected by various rotor design variables of Permanent Magnet Assisted Synchronous Motor (PMa-SynRM). In this paper, Particle Swarm Optimization (PSO) is used in the design process to determine the values of crucial rotor design parameters to achieve optimal performance of a five-phase PMa-SynRM destined for vehicle traction applications. The design variables associated with the geometries of the rotor flux barriers and permanent magnet (PM) are considered in the implementation of the PSO and supported by Finite Element Analysis (FEA). The optimal rotor design parameters are used to obtain the optimized five-phase PMa-SynRM. The performance parameters of the initial motor are compared to the parameters of the optimized motor. The FEA results evidenced that the optimized motor has tremendously reduced the torque ripple from 31.78% for the initial motor down to 13.66% while improving the average torque from 209.89 Nm to 221.27 Nm. Furthermore, the optimized motor has extended the speed range by a good margin, limiting the converter ratings and motor losses when operating at high speeds.