This article proposes a new separated type permanent magnet (ST-PM) excitation machine (STPMM) based on bidirectional field modulation effect, which has the merits of high quality output torque and high power density. ST-PM can be designed by separating rotor surface-mounted PM into one piece radially excited outer PM and two pieces circumferentially excited inner PMs. This design takes advantage of high airgap flux density, which can be achieved by extending the length and adjusting the rotating angle of inner PMs. The operating principle and design method of the proposed STPMM are provided including the key design parameters. The analytical modeling considering rotating angle of inner PMs in STPMM and bidirectional field modulation effect is presented. The electromagnetic performances of the proposed STPMM are evaluated using finite-element analysis (FEA) and compared with the conventional designs. The FEA-predicted results show that the proposed STPMM exhibits high quality electromagnetic performances. The prototype of the proposed STPMM is manufactured and tested, then, the experimental result confirms the advantages of the new machine topology.

中文翻译：

---

基于双向场调制效应的新型分体式永磁电机的设计与分析

本文提出了一种基于双向场调制效应的新型分离式永磁（ST-PM）励磁机（STPMM），具有高质量输出扭矩和高功率密度的优点。ST-PM 可以通过将转子表面安装永磁体分为一件径向励磁外永磁体和两件周向励磁内永磁体来设计。该设计利用了高气隙磁通密度，这可以通过延长内部永磁体的长度和调整旋转角度来实现。提供了所提出的 STPMM 的工作原理和设计方法，包括关键设计参数。提出了考虑STPMM内部永磁体旋转角度和双向场调制效应的分析模型。使用有限元分析（FEA）评估所提出的 STPMM 的电磁性能，并与传统设计进行比较。FEA 预测结果表明，所提出的 STPMM 具有高质量的电磁性能。所提出的 STPMM 原型已制造并测试，实验结果证实了新机器拓扑的优点。