This article proposes a novel topology of consequent-pole switched flux permanent magnet (SFPM) machine with U-shaped permanent magnets (PMs) for torque improvement, which is attractive for traction applications. The proposed machine is geometrically derived from a conventional sandwiched SFPM machine by introducing airspace flux barriers and flat-type PMs. The proposed design can provide an effective circulating path for low-order field harmonics. This property is beneficial for torque capability enhancement. The machine topologies and operating principles are introduced first. Moreover, a magnetomotive force (MMF) permeance-based model for the proposed SFPM machines is employed to analytically reveal the underlying working mechanism. The electromagnetic characteristics of the two proposed SFPM machines are investigated by finite element (FE) analyses and compared with those of the conventional sandwiched SFPM machine. Finally, a 6-/13-pole SFPM machine with a U-shaped PM structure is manufactured and tested to experimentally validate the theoretical and FE analyses.

中文翻译：

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磁极切换式磁通永磁电机的原理研究与性能比较

本文提出了一种具有U形永磁体（PMs）的后极开关磁通永磁体（SFPM）机器的新型拓扑，以改善扭矩，这对于牵引应用具有吸引力。所提出的机器是通过引入空域磁通屏障和扁平型PM从传统的三明治SFPM机器中获得的几何形状。所提出的设计可以为低阶场谐波提供有效的循环路径。该特性有利于转矩能力的提高。首先介绍机器的拓扑结构和操作原理。此外，针对所提出的SFPM机器，基于磁通势（MMF）磁导率的模型可用于分析揭示潜在的工作机制。通过有限元（FE）分析研究了两种建议的SFPM机器的电磁特性，并将其与传统的夹层SFPM机器的电磁特性进行了比较。最后，制造并测试了具有U形PM结构的6/13极SFPM机器，并通过实验对理论和有限元分析进行了验证。