摘要
污秽覆冰环境下绝缘子电气特性是覆冰地区输电线路外绝缘选择的基础,然而国内外针对不同材质绝缘子覆冰闪络特性的对比研究甚少。为此,在人工气候室内模拟覆冰气象条件,采用恒压升降法对3种不同材质绝缘子进行了大量覆冰直流闪络试验研究。分析试验结果得出了目前常用3种绝缘子在覆冰污秽条件下的直流闪络特性,结果表明:严重覆冰条件下,复合绝缘子电弧闪络梯度略高于瓷和玻璃绝缘子,且其污秽特征指数略小;覆冰水电导率和表面污秽对电弧闪络梯度的影响特征指数有明显差异。最后提出了绝缘子串覆冰水电导率及表面污秽共同作用时的直流电弧闪络梯度校正公式。研究结果可为覆冰地区输电线路外绝缘的选择和设计提供参考。
The electrical performance of insulators in freezing condition is a basis for selecting external insulation of transmission lines and substations in icing regions. However, little research has been dedicated to the comparison between composite, porcelain and glass insulators in their DC icing flashover performances. Therefore, we analyzed these perfor- mances on the basis of a number of experiments carried out in an artificial climate chamber. The results indicate that, in severe icing condition, compared porcelain and glass insulators, ice-covered composite insulators have greater flashover voltage grads （FVG） but smaller characteristic exponents that characterize the influence of pollution on icing FVG. The characteristic exponents vary obviously with different salt deposit density and freezing-water conductivity. We also pro- posed a calculation expression for correcting the minimum DC FVG of iced insulators in single or coexisting conditions of salt deposit density and freezing-water conductivity. The results could be referred by the selection and design of trans- mission lines＇ external insulation in ice regions.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2014年第2期434-440,共7页
High Voltage Engineering
基金
国家重点基础研究发展计划(973计划)(2009CB 724501/502/503)
国家创新研究群体基金(51021005)~~
关键词
绝缘子
覆冰水电导率
表面污秽
直流
覆冰闪络特性
电弧闪络梯度
insulators
freezing-water conductivity
salt deposit density
DC
icing flashover performance
flashovervoltage grads
