This article proposed a nonlinear analytical model (NAM) for external rotor permanent magnet synchronous motor (ER-PMSM) considering both rotor and stator saturation. The improved magnetic equivalent circuit (IMEC) is introduced to accurately describe the saturation effect of rotor and stator. The air gap reluctance is replaced by magnetic flux source, and, therefore, the size of IMEC can be reduced while keeping high accuracy. For the air gap field calculation, the analytical solution will be obtained based on the modified boundary condition from the IMEC. The complex permeance function is extended to represent the slotting effect of ER-PMSM. Hence, the NAM will be numerically solved from the combination of IMEC and analytical air gap solution. Both finite-element analysis (FEA) and experiment demonstrate that the proposed model has high accuracy and requires little time.

中文翻译：

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外转子永磁同步电动机的非线性分析

本文提出了同时考虑转子和定子饱和的外转子永磁同步电动机（ER-PMSM）的非线性分析模型（NAM）。引入改进的磁等效电路（IMEC）来准确描述转子和定子的饱和效应。气隙磁阻被磁通量源代替，因此，可以在保持高精度的同时减小IMEC的尺寸。对于气隙场计算，将基于来自IMEC的修改后的边界条件获得解析解。扩展了复磁导函数，以表示ER-PMSM的开槽效果。因此，将通过IMEC和分析气隙解决方案的组合来数值求解NAM。