绝缘子人工污秽试验的分散性分析

Statistical Analysis of Variation Coefficient of Artificial Pollution Flashover Voltage for Insulators

对瓷、玻璃绝缘子污闪电压变异系数的分布规律及统计量进行分析;在此基础上,在一定统计误差和置信水平下,对瓷、玻璃绝缘子污闪试验所需的最少试验次数进行统计估算。结果表明:采用均匀升压法得到的瓷、玻璃绝缘子污秽闪络电压的变异系数近似服从正态分布,期望值为5.32%。采用均匀升压法进行污闪试验时,最小样本数与变异系数密切相关。若要求抽样误差es小于5%,最小有效样本数应不少于6次。

The distribution rules and statistics of variation coefficient of pollution flashover voltage for porcelain and glass insulators were analyzed.On this basis,the minimum number of pollution flashover tests for porcelain and glass insulators was estimated under certain statistical error and confidential level.The results show that for porcelain and glass insulators,the variation coefficients of pollution flashover voltage obtained by uniform pressor method obey normal distribution approximately,and the mathematical expected value is 5.32%.The minimum sample number is closely related with the variation coefficient.If the sampling error es is required to be less than 5%,the minimum effective sample number should be more than 6 times.