Abstract As is well known, the armature current will be ahead of the back electromotive force (back-EMF) under load condition of the interior permanent magnet (PM) machine. This kind of advanced armature current will produce a demagnetizing field, which may make irreversible demagnetization appeared in PMs easily. To estimate the working points of PMs more accurately and take demagnetization under consideration in the early design stage of a machine, an improved equivalent magnetic network model is established in this paper. Each PM under each magnetic pole is segmented, and the networks in the rotor pole shoe are refined, which makes a more precise model of the flux path in the rotor pole shoe possible. The working point of each PM under each magnetic pole can be calculated accurately by the established improved equivalent magnetic network model. Meanwhile, the calculated results are compared with those calculated by FEM. And the effects of d-axis component and q-axis component of armature current, air–gap length and flux barrier size on working points of PMs are analyzed by the improved equivalent magnetic network model.

中文翻译：

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用于分析内置永磁电机永磁体工作点的改进等效磁网络建模

摘要 众所周知，内置永磁(PM)电机在负载条件下，电枢电流会超前于反电动势(back-EMF)。这种超前的电枢电流会产生退磁场，容易使永磁体出现不可逆退磁。为了更准确地估计永磁电机的工作点，并在机器设计初期考虑退磁，本文建立了改进的等效磁网模型。每个磁极下的每个 PM 被分段，转子极靴中的网络被细化，这使得转子极靴中磁通路径的更精确模型成为可能。通过建立改进的等效磁网模型，可以准确计算出每个永磁体在每个磁极下的工作点。同时，将计算结果与有限元计算结果进行比较。并通过改进的等效磁网络模型分析了电枢电流的d轴分量和q轴分量、气隙长度和磁通势垒尺寸对永磁电机工作点的影响。