Abstract Interior permanent magnet synchronous motors (IPMSMs) are commonly used in electric and hybrid electric vehicles. Nissan Leaf electric vehicle (EV) uses skewed-rotor IPMSM as a traction motor. This motor is considered as a benchmark in this work. Although, skewing improves the torque quality of the motor by reducing the torque ripple, it reduces the average torque and increases the motor manufacturing complexity and cost. This article proposes improvements to the benchmark motor torque quality without skewing. The proposed motor uses the same stator winding and rotor magnet topologies of the benchmark motor with the same geometric constraints and magnet volume. Modifications are applied to the placement of the magnets in the rotor and the shape of the flux barriers to achieve the performance requirements. The design procedure of the proposed unskewed design is illustrated. Moreover, the electromagnetic performance of the proposed design is investigated. The design shows competitive performance in terms of the average torque, torque ripple, cogging torque, and efficiency compared to the benchmark motor. The mechanical integrity of the design is also verified. The proposed design is found to be a suitable alternative to the benchmark traction motor with a reduced rotor weight and without skewing.

中文翻译：

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电动汽车用非对称磁通屏障和移位磁铁的非偏斜内置永磁牵引电机的设计

摘要 内置永磁同步电机 (IPMSM) 常用于电动和混合动力汽车。Nissan Leaf 电动汽车 (EV) 使用斜转子 IPMSM 作为牵引电机。该电机被视为这项工作的基准。虽然，偏斜通过减少转矩脉动改善了电机的转矩质量，但它降低了平均转矩并增加了电机制造的复杂性和成本。本文提出了对基准电机扭矩质量无偏斜的改进。所提出的电机使用与基准电机相同的定子绕组和转子磁体拓扑结构，具有相同的几何约束和磁体体积。对转子中磁铁的放置和磁通屏障的形状进行了修改，以达到性能要求。说明了所提议的非偏斜设计的设计过程。此外，还研究了所提出设计的电磁性能。与基准电机相比，该设计在平均扭矩、扭矩纹波、齿槽扭矩和效率方面显示出具有竞争力的性能。设计的机械完整性也得到验证。所提出的设计被发现是基准牵引电机的合适替代品，转子重量减轻且没有偏斜。