摘要：为了对音圈电机的性能进行提升，需要对其磁场分布进行准确的计算。本文首先根据安培分子环流假说，对于均匀磁化的永磁体，用平行于磁化方向的面电流产生的磁场等效替代永磁体所产生的磁场，推导了等效面电流的磁场分布；之后用镜像法替代磁轭，简化计算量；计算了Halbach阵列音圈电机的气隙磁场分布。最后通过使用Ansoft有限元软件对该音圈电机进行仿真，并且将数值仿真解和面电流解析解相比较，两者结果吻合良好。
关键词：Halbach阵列；音圈电机；面电流；镜像法
Abstract: In order to improve the performance of voice coil motor, the magnetic flux density distribution must be calculated accurately. Firstly, according to ampere molecular hypothesis, the magnetic field of sheet current which is parallel to magnetization can replace the magnetic field of equably magnetized magnet. This paper proposed the derivation of magnetic field of sheet current. Secondly, to simplify the calculation, method of images was used to predict the magnetic field by omitting the yoke. At last, the finite element method software Ansoft was used to validate the analytical solution. According to comparison between these two methods, the analytical expression proposed in this paper was precise.
Key words: Halbach array; voice coil motor; method of sheet current; method of images