用冷雾法研究复合绝缘子污秽闪络特性

Using a Cold Fog Test Method to Study Contamination Flashover Performance of Comoposite Insulators

针对绝缘子冬季雾闪的典型气象特征,提出了一种研究复合绝缘子污闪特性的冷雾试验方法。设计了冷雾试验的温度控制方法,即试验时环境温度在-2～2℃范围内循环。根据冷雾中随着温度循环次数的增加试样的闪络电压呈“U”形分布的特征,提出冷雾中复合绝缘子污闪特性的评价方法。最后,分别利用该冷雾试验方法和传统蒸汽雾法评价了一种复合绝缘子短串试样的污秽闪络特性。试验选择一种污秽度、两种初始憎水性状态。结果表明:对于2组具有不同初始憎水性状态的污秽复合绝缘子试样,冷雾法试验结果比蒸汽雾法的试验结果分别低12.8%和25.5%,从而证实了用冷雾法研究复合绝缘子污闪特性的必要性。

A cold fog test method of composite insulators is presented. Firstly, according to the typical meteorological characteristics of the most winter fog problems, the temperature control method is designed, that is to say, the temperature of fog chamber is controlled to cycle in the range of -2-2 ℃ during testing. Then, based on the ＂U＂ distribution of the flashover voltage values of composite insulators with the increase of the temperature cycle in the cold fog, the flashover performance evaluation method is brought forward. Finally, a type of silicone rubber composite insulators was evaluated under one kind of contamination degree and two kinds of hydrophobicity states using this cold fog method and the steam fog method, respectively. It is found that for the two groups of tested samples, the cold-fog test results are lower 12.8% and 25.5% than those in steam fog test, respectively. The test results confirm that the winter fog performance of composite insulators should be investigated using the cold fog method.