试验室绝缘子泄漏电流测量方法研究

监测泄漏电流是评估绝缘子污秽状态的重要手段,介绍了各种湿度下进行人工污秽绝缘子泄漏电流试验的方法。通过理论分析和试验测量,从变压器容量、测量仪器、采样电阻、屏蔽层接地方式及加湿时间等方面探讨了各因素对泄漏电流实验的影响;提出了非饱和湿度条件下雾湿润效果的检测方法,并通过人工污秽试验进行了验证。结果表明:湿度、盐密及绝缘子的等效电容越大,变压器的容量要求也越大;采样电阻过大,将影响泄漏电流值的准确度;屏蔽层采用两端接地是行之有效的方法;加湿时间为9min时,泄漏电流达到最大值。

Study on Monitoring Method of Leakage Current of Contaminated Insulator for Lab Use

Leakage current monitoring is an important measure for evaluation of contamination status of an insulator. Leakage current measurement method on contaminated insulator at different hu- midity was introduced. Based on theoretical analysis and test measurement. Factors effecting leakage current measurement were approached such as transformer capacity, measuring instruments, sampling resistor, grounding mode of shielding, humidifying duration, etc.. A measurement method for evaluating the humidifying effect of fog under non-saturate conditions was proposed and verified with artificial pollution tests. The results show that the higher the humidity, salt deposit density and equivalent capaci- tance of the tested insulator, the large capacity of the transformer required, excessive high sampling re- sistance might effect the accuracy of leakage current measurement. The effective grounding for shielding layer shall be made at both ends. The maximum leakage current reached at humidifying time of 9 min.