径轴向聚磁型永磁推进电机优化设计与分析

Design Optimization and Analysis of Radial-axial Flux-focusingPermanent Magnet Propulsion Motor

为了进一步实现永磁电机磁负荷和转矩密度的提升,提出了一种径轴向聚磁型永磁推进电机结构,转子永磁体在Halbach径向聚磁结构基础上进一步结合轴向延伸永磁体,实现了永磁磁场的径轴向聚磁。针对该种新型电机,本文详细研究了其结构特点,利用有限元分析了所提电机结构的电磁性能。首先对比分析了定转子等长结构、定转子不等长(overhang)结构输出性能,并对对称型overhang结构进行了参数化优化,有效提升了电机转矩密度。最后,利用三维有限元模型对比分析了径向overhang和径轴向overhang电机的电磁性能,结果发现径轴向overhang电机空载磁密提升了6%、输出转矩增大了1.3%、转矩脉动减少了0.4%,进一步验证了电机性能的优越性。

In order to improve magnetic load and torque density of permanent magnet motors,the radial-axial flux-focusing permanent magnet propulsion motor was proposed,which could improve the motor torque output capacity by using the flux-focusing ability of axially magnetized permanent magnets combined with Halbach array permanent magnets.Aiming at this new type of motor,this paper studied its structural characteristics in detail and analyzes the electromagnetic performance of the proposed motor structure using finite element.Firstly,the traditional and overhang structures were compared and analyzed,and the symmetrical overhang structure was optimized to further improve the torque characteristics.Finally,the initial radial overhang and optimized radial-axial overhang motors were simulated under no load and load conditions using the 3D electromagnetic field model,the no load magnetic flux and the average torque are found to increase by 6%and 1.3%,and the torque pulsation is reduced by 0.4%,which further verified the superiority of the motor performance.