永磁转子偏转式三自由度电机建模与结构分析

针对以往研究中单层结构永磁转子三自由度电机转矩特性的不足,提出一种新型永磁"蝶形"转子偏转式三自由度运动电机,采用球坐标系下分离变量法和洛伦兹力法分别对电机气隙磁场和转矩进行解析建模,确定气隙磁场空间谐波含量和结构参数对基波磁通密度和转矩幅值的影响,同时进行三维有限元仿真分析.通过研究两种计算方法下气隙磁场、自转和偏转转矩的特点及规律,并进行对比分析.结果表明:"蝶形"永磁转子结构的气隙磁通密度分布和转矩特性优于单层结构,气隙磁通密度径向分量空间分布近似平顶波,转子中间层磁极的气隙磁通密度幅值最大,解析法与有限元法的计算误差均小于6.7%.

Modeling and structure analysis of a permanent magnet rotor deflection type 3-DOF motor

A new 3-DOF deflection type PM motor with a "butterfly" type rotor is proposed in this paper. In order to overcome the disadvantages of torque characteristics of the single layer structured permanent magnet 3-DOF motor mentioned in the previous research, the air-gap magnetic field and electromagnetic torque of the motor are analytically modeled using the seperation of variables method and the Lorentz force method in spherical coordinates. The space-harmonics of the magnetic field and the influence of structural parameters on the fundamental flux density and torque amplitude are defined; also the 3D finite element simulation and analysis are performed simutaneously. In the present study, the distribution characteristics and the regularities of air gap magnetic field, spin and deflection torque are investigated under different calculation methods. Simulation results show that the flux density distribution and torque characteristics with "butterfly" type permanent magnet rotor structure is superior to single layer structure. The spacial distribution of radial component of the flux density approximates the flat top waves and its maximum magnitude values appear in the middle layer of the rotor poles. The computation errors by the analytical and finite element methods are all less than 6.7%.