磁路互补型模块化磁通切换永磁直线电机

Novel Modularized Flux-Switching Permanent Magnet Linear Machine With Complementary Magnetic Circuits

新型模块化初级永磁直线电机的永磁体和电枢绕组都置于初级短动子,而次级长定子结构简单,仅由导磁铁心组成,若应用在轨道交通等长定子等场合,可大大降低系统成本。在深入分析现有电机结构特点的基础上,提出一种基于磁通切换原理磁路互补的新结构。结构的互补性使每相绕组的反电势更正弦、电机总的定位力更小。介绍了模块化初级永磁直线电机的结构特点和运行原理,并基于有限元法,研究了其静态特性,具体包括对空载和单相绕组通电时的磁场及气隙磁通密度、绕组永磁磁链、空载反电动势、定位力、绕组电感以及静态推力等,并分析了永磁磁场和电枢磁场之间的相互耦合作用对电感特性的影响。理论分析和样机实验结果验证了设计方案的正确性和有效性。

In modularized primary permanent magnetlinear （MPPML） machine, both the magnets and armaturewindings are placed in the short primary mover, while the longsecondary stator is only made of iron, being perfectly suitablefor the long stator applications, such as urban rail transit. Basedon the depth analysis of the structure of the MPPML machine,a novel topology of MPPML machine adopting＂flux-switching＂ principle with complementary magneticcircuit is proposed. Due to the complementary structure,sinusoidal phase back-EMF is obtained and the total coggingforce of the machine is minimized. The structure features andoperation principle of the machine are introduced. Based onfinite element method, the static characteristics of the machine,including magnetic fields and air-gap flux density distributionsat the conditions of no-load and one-phase-on are analyzed,respectively. Consequently, the open-circuit flux-linkage,back-EMF, cogging force, winding inductance and static thrustforce are deduced. Additionally, the effect of the cross-couplingbetween the permanent magnet field and armature field on theinductance is taken into account. The theoretical analysis andexperiments on a prototype machine verify the correctness andeffectiveness of proposed machine.