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混合式步进电动机磁场分布主要有3个特点：内部径向磁场和轴向磁场并存，磁路呈三维分布；磁路局部饱和现象严重，导致电机特性呈现非线性特性；气隙以及邻近部位磁场变化剧烈。采用有限元算法进行计算时，需要建立电机的三维模型，剖分网格要足够精细，尤其是电机气隙以及齿层部位的剖分网格须特别精细，导致电机模型的剖分文件过大，容易发生计算机内存溢出，也延长了计算时间。因此，常规的三维有限元计算方法对混合式步进电动机不甚适用。另一方面，气隙比磁导法和齿槽比磁导法等基于磁路计算的工程方法运算速度快，但精度偏低，尤其是在磁路发生严重饱和的情况下。因此，有必要在保证计算精度的前提下，采用必要的简化措施对混合式步进电动机进行分析。该文以一台两相混合式步进电机为例，提出通过模型等效变换的方法来获得二维等效模型，通过二维有限元软件对其静态特性进行计算，并将计算结果进行后处理(即模型反变换)，实现原电机的性能仿真。仿真结果与实测结果基本一致，证明了基于模型变换的仿真分析方法的可行性与准确性。“,”Magnetic field distribution in hybrid stepping motors has the following characteristics: 1) The field is three dimensional (3D), containing both axial and radial fields. 2) Local saturation occurs, leading to nonlinear properties. 3) The field nearby the air gap and teeth varies significantly. Due to these, a 3D finite element method (FEM) is needed to analyze the performance, and the mesh, especially those at the air gap and teeth layers, must be sufficiently dense, so as to improve the simulation accuracy. As a result, the meshing file is very large, consuming much computer memory and computation time. Therefore, the traditional 3D FEM simulation is somewhat inapplicable for the hybrid stepping motors. There are also analytical methods based on calculating the machine magnetic circuit, which are fast but suffer from low calculation accuracy, especially when severe saturation occurs. Therefore, a simplified analysis method with sufficient accuracy is preferable. In this paper, while taking a two phase hybrid stepping motor as an example, a model transformation-based analysis method is proposal, by which the original model of the hybrid stepping motor is approximate to a two-dimensional (2D) equivalent model. The static performance result is acquired from the equivalent model using 2D FEM simulation software. Then the properties of the original machine are solved through the post-processing of model counter-transformation. Feasibility and accuracy of the proposed method is verified by comparing the simulation and experimental results.