盐雾环境下清洁和染污绝缘子交流耐压特性  

AC Withstand Characteristics of Clean and Polluted Insulators in Salt-fog

作　　者：刘琴 李瑶琴 谢梁 徐涛 万小东 LIU Qin;LI Yaoqin;XIE Liang;XU Tao;WAN Xiaodong(China Electric Power Research Institute,Wuhan 430074,China)

机构地区：[1]中国电力科学研究院有限公司

出　　处：《高电压技术》2018年第9期2828-2834,共7页High Voltage Engineering

基　　金：国家电网公司科技项目(特高压输电工程应对复杂环境的外绝缘关键技术研究)~~

摘　　要：盐雾是沿海及盐碱地区一种特殊的气象环境,盐雾环境下绝缘子的耐受电压会显著降低,威胁到输电线路的安全运行。为了研究绝缘子在盐雾环境下的耐压特性,对悬式瓷绝缘子XWP–300表面清洁和染污2种情况下的试品进行了盐雾试验。研究结果表明,当盐密和雾水电导率增大到一定程度时,绝缘子的50%耐受电压（U（50%））趋于稳定;雾水电导率相同的情况下,绝缘子在NaNO3盐雾中的50%U较在NaCl盐雾中的低,Na2SO4盐雾中的U（50%）较高,但3种盐雾中的U（50%）差异较小,盐雾对绝缘子耐受电压的影响主要取决于雾水电导率。分析清洁和染污绝缘子盐雾试验过程中的泄漏电流发现,清洁绝缘子表面泄漏电流幅值随时间呈现快速增长到最大值后趋于稳定的趋势,而染污绝缘子表面泄漏电流幅值随时间呈现先增大后减小的趋势。此外,根据清洁绝缘子在电压恒定时表面泄漏电流随雾浓度变化的规律,提出了清洁绝缘子在盐雾中采用电压升降法进行试验的改进方案。Salt fog is a unique weather in coastal and saline-alkali area, which can significantly decrease the flashover voltage of insulators. In order to study the withstand characteristics of insulators in salt fog, the insulator specimens of cap-and-pin ceramic insulator XWP-300 were tested in artificial salt fog under conditions of non-pollution and pollution. The results indicate that the 50% withstand voltage（U50%） tends to be saturated when the SDDρ（salt deposit density） and fog conductivity increase to some degree. Under the same conditions of water fog conductivity, The U50% of insulators is lower in NaNO3 fog than in Na Cl fog, while it is higher in Na2SO4 fog. But the difference of U50% is not noticeable in these three kinds of salt fog, so the fog conductivity is the main factor considering the influence of salt fog on the withstand voltage of insulators. On the basis of analyzing the leakage currents of polluted and clean insulators, it is found that the clean insulators＇ leakage current will tend to be a constant after rapidly reaching its maximum, while to the polluted insulators withstanding a voltage, the leakage current pulse will decrease continually and slowly after reaching its maximum. Moreover, on the basis of a rule that the leakage current merely changes with the fog concentration ofr clean insulators under constant voltages, an improved scheme for voltage lifting and lowering method of clean insulators in salt fog test has been put forward.

关 键 词：盐雾 绝缘子 人工污秽试验 50%耐受电压 泄漏电流 

分 类 号：TM216[一般工业技术—材料科学与工程]