考虑层间效应的复磁导率铁芯频变模型

Frequency-depended Modeling for the Core of Power Transformer Based on Complex Permeability Considering Interlaminar Effects

现有变压器铁芯模型的建立通常未能充分考虑层间效应的影响,针对该问题,建立了考虑层间效应的铁芯复磁导率2维模型,推导了基于该复磁导率的铁芯频变阻抗表达式。在此基础上应用改进矢量匹配法对铁芯频变阻抗表达式进行了有理函数逼近,然后应用电路综合方法建立了铁芯的6阶Foster电路模型。将所建模型与未考虑层间效应的复磁导率一维模型进行了对比分析,结果表明:考虑层间效应的2维模型所得阻抗值相比一维模型所得阻抗值要低,根据铁芯参数不同,其差值约为1.3%~4%。因此,建模时有必要考虑层间效应。论文研究为基于FRA的变压器绕组准确建模打下了基础,同时也可为变压器宽频建模提供参考。

The establishment of the existing transformer core model usually fails to fully consider the influence of the interlaminar effects. In order to solve this problem in transformer modeling, the influence of interlaminar effects on the complex permeability of the iron core was considered, and a two-dimensional model of the complex permeability of the iron core based on the Interlaminar effects was established. The modified vector fitting was used to fit the iron core frequency-dependent impedance expression. Then, a six-step Foster circuit model of the core is established by applying a circuit synthesis method, and it was compared with the one-dimension model of the complex permeability. The results show that the impedance value obtained by two-dimensional model considering the interlaminar effects is lower than that obtained by one-dimension model, the difference is about 1.3%~4% depending on the parameters of different cores.Therefore, it is necessary to consider the interlaminar effects in modeling. This paper lays the foundation for the accurate modeling of transformer winding based on FRA, and it also provides a reference for wideband modeling of transformers.