定子永磁型磁通切换电机齿槽转矩及其抑制技术

Overview of Cogging Torque and Its Suppression Technologies in Flux-switching Permanent Magnet Machines

齿槽转矩是永磁电机特有的问题之一,其产生原因是在不通电的情况下永磁体与有槽铁心的相互作用。磁通切换永磁电机作为永磁电机的一种,由于其特有的双凸极结构和聚磁效应,导致该电机的齿槽转矩比常规转子永磁型电机大,从而引起电机转矩脉动、振动和噪声,尤其会影响电机低速时的性能。首先介绍了磁通切换永磁电机齿槽转矩的产生机理,在此基础上介绍了解析法和有限元法这两种通用的齿槽转矩抑制方法,并总结了其各自优点和缺点。针对磁通切换永磁电机这一特定电机类型,从本体角度分析各种抑制齿槽转矩的研究方法,并进行了总结。讨论了在电机设计初始阶段的一些抑制措施和辅助的方法,如斜极、辅助槽和削角等。最后,对该电机齿槽转矩未来的研究方向进行了展望。

Cogging torque is a load-independent component generated by the interaction between permanent magnet （PM） and slotted core, which especially exists in PM machines. As a family member of PM machines, flux-switching PM （FSPM） machine typically suffers from severe cogging torque due to its doubly salient structure and flux-concentration effect, causing undesired torque pulsations, acoustic noise and vibration, especially at low speed. In this paper, an overview on cogging torque and its suppression technique was conducted. The reason why cogging torque exists in FSPM machines was unveiled. Then, two general techniques utilized to study cogging torque, namely analytical method and finite element method, were introduced, and summarized with their advantage and disadvantage. Thereafter, different suppression techniques of cogging torque based on FSPM machine itself were reviewed and analyzed. Besides, the reduction technique during machine design stage and some auxiliary methods, like skewing, dummy slots, chamfering, etc., were also discussed and compared. Finally, the future trends on the cogging torque and suppression methods of FSPM machines were prospected.