油气套管连接的变压器绕组变形试验差异分析

Difference Analysis of Oil-gas Bushing-connected Transformer Winding Deformation Test

油气套管连接的变压器现场绕组变形试验只能通过套管末屏取信号的方式进行。套管末屏以及气体绝缘母线部分的影响导致所得幅频响应曲线与出厂试验、交接试验所得曲线有较大不同。本文采用构建变压器等效模型的方法,对比套管末屏取信号的现场试验与绕组端部取信号的交接试验所得幅频响应曲线,从低频率段、中频率段、高频率段的曲线以及幅值的变化方面分析两者的差异及产生原理,得出两者曲线不宜纵向对比的结论,并为现场试验提出相关建议。

The field winding deformation test of the transformer with oil and gas bushing connected can be processed only by acquiring signals at the bushing tap. The influence of the bushing tap and the gas insulated line section makes the amplitude- frequency response curves different from the factory test and commissioning test. The method of constructing equivalent model of transformer is adopted, and the amplitude-frequency response curves of the field test at the bushing tap signal and the commissioning test at the winding end signal are compared. Differences and production principles are analyzed from the curve variation and amplitude variation of low frequency segments, medium frequency segments and high frequency segments. It＇s concluded that the curves should not be contrasted vertically, and suggestions for on-site tests are given.