绝缘子覆冰是一种特殊形式的污秽,一般来说覆冰前绝缘子表面存在污秽才会导致绝缘子在运行电压下发生冰闪。为模拟和表征污秽对绝缘子冰闪电压的影响,根据多功能人工气候室的试验结果,探讨了染污方式,即固体涂层法或覆冰水电导率法对两种型式的复合绝缘子覆冰直流电压的影响,分析了人工覆冰绝缘子的两种染污方式之间的关系。研究结果表明:在对冰闪电压的影响上,两种染污方式存在等价性,但采用覆冰水电导率模拟污秽时试验简便,试验结果的分散性相对较小;染污方式对覆冰绝缘子的放电路径有影响,固体涂层法染污的复合绝缘子冰闪路径沿着绝缘子表面,由于憎水性的影响,其间歇性电弧容易烧伤伞裙表面,导致憎水性下降或丧失;覆冰水电导率模拟污秽时,放电沿着冰层外表面,试验结果的分散性较小,试验简便和易于控制。因此,建议试验时可以采用覆冰水电导率法模拟污秽。
How to simulate and figure out the effects of pollution on icing flashover voltage is the foundation of designing anti-icing method. On the basis of the test results carried on the multi-functional artificial climate chamber, we discussed the effects of two different pollution manners, solid layer pollution manner and ice water conductivity manner, on DC flashover performance of 110 kV composite insulators, and analyzed the relationship between the two different pollution manners. The test results show that: while considing the effects on icing flashover voltage, two different pollution manners have a corresponding relationship between them. But ice water conductivity manner is more simple than solid layer pollution manner, and has smaller dispersion than the latter. Pollution manners affect the flashover path of icing insulators, and the flashover path occurs on the sub surface of icing composite insulator that is pre-polluted by solid layer pollution manner. Owing to hydrophobicity, it is easy for intermittent partial arcs between ice and insulator's surface to burn, which lowers the hydrophobicity. The arc develops outside surface of icing layer while pre-polluted by ice water conductivity manner will have smaller dispersion. Therefore, ice water conductivity manner should be suggestd to simulate pollution.