电力变压器绕组变形诊断分析

应用频率响应分析法判断变压器绕组在遭受短路冲击后是否发生严重变形具有重要的意义。介绍了频率响应法的基本原理并在大量实例的基础上,提出了横向比较分析法,即通过比较变压器三相绕组频率响应特性曲线的一致性及与同厂同型变压器绕组频率响应曲线对比来分析判断绕组变形程度;提出了定量表示2条曲线一致性的相关系数的概念,得出相关系数大小与曲线一致性的关系;提出了测试接线方法及测试过程中应注意的主要事项。

Analysis on Winding Deformation Diagnosing of Power Transformers

It's significant to use frequency response analysis (FRA) to determine whether the windings of power transformers have serious deformation after short-circuit current shock. In terms of the fundamental principle of FRA and a great deal of field experiences, a horizontal comparing approach is presented, that is, to analyze the windings' deformation in terms of comparing the coherence of the windings' frequency response characteristic curve of one phase with those of other two phases as well as in comparison with other same type transformers' curves manufactured by the same factory. Furthermore, a pertinence coefficient is presented to quantify the coherence of two curves. And the relationship between the pertinence values and the curves' coherence is obtained. In particular, the test method and main cares needing careful attentions are also described in this paper.