A novel parallel-hybrid dual permanent magnet (PM) machine topology with both enhanced torque density and improved flux weakening capability is proposed for electric vehicle propulsion in this paper. The key is to artificially construct the harmonics diversity with a single-layer concentrated armature winding in the stator and thus simultaneously couple the armature field with the excitation field produced by slot PM, rotor PM, and stator dc source, respectively. Enhanced torque density is obtained in this new topology due to the symmetrical flux-modulation effect between dual PM sources. Moreover, benefiting from a parallel excitation characteristic of hybrid magnetic circuit, the demagnetization risk is significantly mitigated for slot PM source and thus an extended flux weakening range is obtained. In this paper, the proposed new topology and its design mechanism are investigated, along with its electromagnetic performance evaluated based on finite-element analysis. Further, some leading design parameters are analyzed and determined to provide a design guideline for the proposed new topology. Finally, a prototype is built and fully tested. Relevant experimental results agree well with the finite-element predication.

中文翻译：

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基于电枢谐波分集的新型并联-混合-励磁双永磁电机设计用于电动汽车推进

本文提出了一种新型并联混合双永磁 (PM) 电机拓扑结构，该拓扑具有增强的转矩密度和增强的弱磁能力，用于电动汽车推进。关键是通过定子中的单层集中电枢绕组人为地构建谐波分集，从而同时将电枢场与分别由槽 PM、转子 PM 和定子直流源产生的励磁场耦合。由于双 PM 源之间的对称磁通调制效应，在这种新拓扑中获得了增强的转矩密度。此外，受益于混合磁路的并联励磁特性，槽式永磁体源的退磁风险显着降低，从而获得了更大的弱磁范围。在本文中，研究了所提出的新拓扑及其设计机制，以及基于有限元分析的电磁性能评估。此外，还分析并确定了一些主要设计参数，以为所提出的新拓扑提供设计指南。最后，构建原型并进行全面测试。相关实验结果与有限元预测一致。