考虑多点接地故障的变压器铁心均匀化建模方法

A Homogenization Modeling Method of Transformer Cores Considering Multi-point Grounding Faults

铁心多点接地故障是变压器发生频率最高、危害最严重的故障之一。针对变压器铁心发生多点接地时故障电流的计算问题进行研究.首先提出了一种考虑铁心多点接地故障的均匀化方法,然后基于所提均匀化方法建立了变压器多点接地有限元计算模型,并在三维涡流场下对试验变压器的故障电流进行有限元计算与分析,最后通过多点接地试验对模型进行验证。结果表明,有限元仿真结果与试验结果相近,说明基于所提出均匀化建模方法可以有效地计算变压器多点接地故障电流,并能满足工程上的精度要求。

The multi-point grounding fault of transformer cores is one of the most frequent and serious faults in transformer＇s faults. In order to calculate the multi-point fault current of the core, firstly a homogenization modeling method of the transformer core considering the multi-point grounding fault was proposed. Secondly, based on the homogenization method, a FEM model of the core with multi-point grounding fault was established, and the FEM analysis of the test transformer under the three-dimensional eddy current field was carried on. Finally, the proposed model was verified by the multi-point grounding test. The results show that the finite element simulation results are close to the test results, it verifies that based on the proposed modeling method, the fault current can be calculated effectively and the accuracy of the engineering can be satisfied.