This article is a contribution to answer the following question: Is it possible to design a permanent magnet machine with the performance expected from rare-earth magnets but at a lower cost? Performance being understood as torque, size, efficiency, demagnetization, and temperature rise together. The question is addressed with a systematic exploration of different interior permanent magnet machine topologies mixing rare-earth and ferrite permanent magnets. The study starts from a production baseline, the Prius 2010 traction motor, with interior magnets placed in a single V pattern. It investigates various rotor designs, most specifically, single V and double V patterns as well as spoke configurations. The stator cross-section design and winding selection are fixed, providing a solid comparison basis from the point of view of machine cooling. For each rotor design, torque potential and machine material cost are assessed, the latter expressed as torque per dollar. A promising configuration was found based on a spoke pattern for which further modeling was performed to assess efficiency as well as mechanical strength and resistance to short circuits and to demagnetization. It reduces the rare-earth magnet volume by over 60%.

中文翻译：

---

具有多种磁铁类型的低成本内置永磁电机

这篇文章是回答以下问题的贡献：是否有可能设计出具有稀土磁体预期性能但成本更低的永磁电机？性能被理解为扭矩、尺寸、效率、退磁和温升。该问题通过对混合稀土和铁氧体永磁体的不同内部永磁电机拓扑结构的系统探索来解决。该研究从生产基线开始，即普锐斯 2010 牵引电机，其内部磁铁放置在单个 V 形图案中。它研究了各种转子设计，尤其是单 V 型和双 V 型以及辐条配置。定子截面设计和绕组选择是固定的，从机器冷却的角度提供了坚实的比较基础。对于每个转子设计，评估扭矩潜力和机器材料成本，后者表示为每美元扭矩。基于辐条图案发现了一种有前途的配置，对其进行了进一步的建模以评估效率以及机械强度以及抗短路和退磁能力。它减少了60%以上的稀土磁铁体积。