污秽瓷绝缘子泄漏电流的估算方法

Method of Evaluating Leakage Current of Contaminated Porcelain Insulators

泄漏电流的检测和分析作为污秽绝缘子在线监测的一种方法近年来引起大量关注。国内外研究表明,泄漏电流受作用电压和环境因素等的影响,但探索绝缘子泄漏电流与各影响因素之间的本质联系较少。为此,以单片的普通悬式绝缘子XP-70为试品,在人工雾室中进行了大量的人工污秽试验,利用最小二乘原理分析得到了作用电压U、盐密ρESDD和相对湿度RH与泄漏电流的具体关系式。结果表明:人工污秽试验中,绝缘子的泄漏电流幅值Ih与作用电压U、盐密ρESDD和湿度RH均有关,盐密、湿度影响较明显;随着ρESDD的增加,Ih按幂函数规律增加,特征指数为0.413;随着U和RH的增加,Ih均按指数函数规律增加,特征指数分别为0.044和9.815。研究结果对于工程中建立基于绝缘子泄漏电流的污秽度评估系统有一定的参考价值。

The measurment and analysis of leakage current is an important means of on-line detection of polluted insulators, which has attracted a lot of research and attentio on it. The previous study results show that leakage current has a correlation with the applied voltage and environment factors, but there is few study about the elemental relation between leakage current and influence factors. According to the test results of the single XP-70 insulator carried in the artificial fog chamber,it is analyzed that the effects of the applied voltage U, the equivalent salt deposit density ρESDO and the relative humidity density RH on the leakage current of the XP-7 insulator based on the least squares algorithm in this paper. The result shows that the peak maxmim of leakage current Ih has a correlation with U, ρESDO and RH, the latter two contribute dominant on Ih. The Ih ineases with the increase of ρESDO by an power function with a postive index whichi is 0. 413, while ineases with the increase of both U and RH by an exponential function with a postive index that is 0. 044 for U and 9. 815 for RH. The result could be used as references to estamnate the contamination condition of insultors based on evaluating leakage current ,which is of great value for providing technical references to the external insulation design and anti-polluting in Western China.