Halbach阵列永磁球形电动机转矩的三维有限元分析

为分析Halbach阵列永磁球形电动机复杂边界条件对电机性能的影响，采用有限元法对电机转矩特性进行了研究．建立了Halbach阵列永磁球形电动机三维有限元模型，得到了电机转矩的空间分布，并与解析法得到的结果进行了对比分析．在保证Halbach阵列永磁球形电机体积不变的情况下，分析了电机结构参数对电机性能的影响．对不同磁体结构球形电动机产生的自转转矩和倾斜转矩进行了比较．漏磁、磁场谐波及各自由度之间的电磁耦合对转矩特性的影响可以在有限元法中得到体现，使其与解析法得到的结果有所差别．永磁球形电动机采用Halbach阵列磁体结构后，转矩的输出能力得到了提高．在电机结构参数中，转子磁体厚度、定子线圈高度、内径及外径对电机的输出转矩能力具有较大的影响．结果表明在提高电机转矩输出能力上，电机结构参数存在最优值．

3-D Finite Element Torque Analysis of a Halbach Array PM Spherical Motor

The torque characteristic of the Halbach array PM spherical motor with complicated boundary conditions is analyzed using finite element method （FEM）. A three-dimensional （3-D） finite element model of the Halbach array PM spherical motor is built. The space distributions of the torque are obtained by FEM ,which are compared with those obtained by analytical method. The effects of the structure parameters of the motor on the performance of the motor are discussed. The rolling torque and tilting torque obtained by different magnet arrays are compared. The influences of flux leakage ,magnetic harmonic and electromagnetic coupling among all degrees of freedom on the torque characteristic can be considered in FEM, which makes results of FEM and analytical method different. The torque output capacity of the Halbach array PM spherical motor is improved. The magnet thickness, the height of coils ,the inner and outer diameters of coils play an important role in the output torque capacity. The results indicate the structure parameters of the Halbach array PM spherical motor have optimum values in improving the torque output capacity.