预染污方式对瓷和玻璃绝缘子人工覆冰交流闪络电压影响的研究

Effects of Pre-polluting Modes on Artificial Icing AC Flashover Characteristics of Porcelain and Glass Insulators

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。如何模拟和表征污秽对绝缘子冰闪电压的影响,是防冰抗冰设计的基础。笔者根据人工气候室的试验结果,探讨了染污方式,即固体涂层法染污或覆冰水电导率染污对3种型式的瓷和玻璃绝缘子覆冰交流闪络电压的影响,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,固体涂层法染污的绝缘子冰闪路径沿着绝缘子表面;覆冰水电导率模拟污秽时,放电沿着冰层外表面,因此试验结果的分散性较小,试验简便和易于控制。

Insulator icing is a special form of pollution. Generally speaking, icing flashover of insulator happens under operation voltage only as pollution exists on the insulator surface before icing. Based on the test results from the artificial climate chamber, this paper discusses the effects of two pollution modes, i.e. solid layer pollution mode and ice water conductivity mode, on AC performance of three kinds of porcelain and glass insulators, and analyzes the relationship between the two different pollution modes. The test results show that： the two pollution modes are equivalent for the effects on icing flashover voltage, while the ice water conductivity mode is more convenient in test than the solid layer pollution mode with smaller data dispersion; pollution modes impose effect on the flashover path of icing insulators; the flashover path of icing insulator pre-polluted by solid layer pollution mode occurs on the surface of the insulator; and arc develops on outside surface of icing layer of the insulator pre-polluted by ice water conductivity mode, leading to smaller data dispersion, simple test process and easy control.