油浸变压器绝缘受潮的介质响应诊断技术研究

Study on the Dielectric Response Diagnostic Techniques for Oil-Immersed Transformer Insulation Damp

现场条件下准确诊断变压器的受潮程度一直是难点,通过对变压器及油纸模型的介质响应测试,分析温度及水分对介质响应的影响。结果显示温度升高主要使介质响应曲线在频率轴方向向高频方向移动,而水分增加主要使介质响应曲线在介质损耗轴方向向上平移。复电容虚部极小值大小随温度变化不明显,但却随着水分的增加呈指数形式显著增加,这一规律,为准确判断变压器的受潮程度提供了一种依据。

It has been a problem to accurately diagnose the moisture level of transformers under field conditions.Therefore,the effects of temperature and moisture content on the dielectric response are analyzed by the dielectric response testing on transformers and oiled paper model.The results show that with the increase of temperature,the dielectric response curve moves to the high-frequency area in frequency axis,while with the increase of moisture content,the dielectric response curve pans up in the longitudinal axis.In addition,the minimal value of the complex capacitance＇ s imaginary part changes insignificantly with the change of temperature; but it increases in exponential form with the increase of moisture content.This conclusion can provide a basis for accurate diagnosis of the moisture level.