Performance analysis and design optimization of asymmetric interior permanent magnet synchronous machine for electric vehicles applications

Abstract A novel asymmetric delta‐type and Spoke‐type interior permanent magnet synchronous machine (ASD‐IPM) is proposed for electric vehicles (EVs) application that uses the magnetic field shifting technique to maximise the average torque and lessen torque ripples. The proposed ASD‐IPM is deduced from the conventional asymmetric spoke and V‐shape IPM by attaching additional asymmetric flux barriers (AFB) to the left side of the spoke‐type PMs and to the other side of the delta‐type PMs. This configuration helps in reducing the leakage flux and achieving good flux concentration. The proposed design is optimised through a Genetic Algorithm (GA) to investigate the electromagnetic performances at no‐load and on‐load conditions. Also, the efficiency maps of both the proposed design and conventional design are analysed and compared. The results show that the proposed ASD‐AIPM has superior efficiency and a favorable torque profile, making it a suitable choice for electric vehicle applications. Furthermore, the proposed design is rescaled to the Toyota Prius 2010 design, with the only change in the slot/pole pair combination due to the presence of spoke‐PMs in the proposed design. The proposed ASD‐IPM achieves 7% higher torque than the existing Toyota Prius 2010 model. The efficiency maps of the rescaled design are also analysed and compared.