自然污秽与人工污秽绝缘子等价性分析方法研究

Research on Analysis Method of Equivalence Between Natural Polluted Insulators and Artificial Contaminated Insulators

污闪事故长期威胁着我国电力系统的安全稳定运行,经过多年防污治理工作及治理规程的完善,中国的污闪事故大大减少,但关于污闪机理的分析研究工作仍需继续开展。人工污秽试验是分析研究绝缘子外绝缘性能的重要方式之一,但人工污秽试验与自然污秽试验之间等价性的问题并没有得到妥善解决。目前常用的分析方法是以等值盐密作为绝缘子污秽程度评价标准,用在清洗污秽溶液中产生相同电导率的NaCl盐量表示污层可电离物质的导电性。事实上,该方法并没有完全解决两者等价性的问题。首先提出一套评估人工污秽与自然污秽试验结果等价性的数学方法,并利用本方法在不同污秽度度量标准体系下分析人工污秽试验与自然污秽试验结果的等价性。分析结论表明,以绝缘子整体电导率作为衡量参数时,自然污秽绝缘子的外绝缘性能与人工污秽绝缘子外绝缘性能之间的等价性较好。

The pollution flashover has been threatening to the security and stability of the power grid operation in our country. After years of efforts in anti-pollution governance and perfection of relating regulations, the pollution flashover accidents have been greatly reduced. But the mechanisms of pollution flashover still need further research. Artificial contamination test is one effective method to study and analyze the outer insulation performance of the insulators. However, the equivalence problem between artificial pollution tests and natural contamination test still has not been properly addressed. One widely-used analytical method is to use equivalent salt deposit density（ESDD） as the evaluation criteria of the contamination degree on insulator surface. ESDD use the amount of NaCl, which can produce the same conductivity in an equal amount of water with the contamination washed from insulator surface, to represent the conductivity of ionizable substance in contamination layer. In fact, this does not completely solve the equivalence problem between the two different contamination tests. In this paper, a new method was proposed to evaluate the equivalence between naturally contaminated insulators and artificially contaminated insulators. And it was used to analyze the equivalence problem in different evaluation system for contamination severity. The paper showed that the equivalence between natural and artificial contamination test was better solved when using surface conductivity as the evaluation criteria for contamination severity.