高海拔因素对绝缘子污闪特性的影响  

Influence of High Altitude Factor on the Contamination Flashover Performance of Insulators

作　　者：关志成[1] 李健[1] 周军[2] 王黎明[1] 

机构地区：[1]清华大学深圳研究生院,深圳518055 [2]中国电力科学研究院,北京100192

出　　处：《高电压技术》2012年第10期2481-2491,共11页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2011CB209406;2009CB724503)~~

摘　　要：我国西电东送、西藏联网等工程对高海拔条件下的外绝缘特性研究提出迫切需求。为此,首先总结了国内外关于高海拔、低气压条件下绝缘子污闪特性的研究,重点介绍了我国近年来在该领域问题研究上取得的成果,总结发现气压对污闪电压的影响可以用气压下降指数n来衡量,统计分析表明,交流悬式的n值平均值为0.49,交流支柱为0.48;直流悬式的n值平均值为0.27,直流支柱为0.42。然后对低气压下污闪电压下降机理的问题进行了深入讨论,认为低气压下电弧的伏安特性下降和伞裙间电弧桥接是导致污闪电压下降的2个原因。同时分析了表征气压和海拔高度对污闪电压影响的气压下降指数n和海拔修正系数K的物理意义,认为K有明确的物理意义。最后比较了海拔高度对电晕起始电压、空气间隙击穿电压和污闪电压影响的严酷程度,结果表明,在合理伞形的前提下,高海拔条件下污闪电压的下降幅度不是最严重。According to the urgent needs of the investigation of the outdoor insulation performance in high altitude for the power transmission from west to east and Tibet interconnection,we summarize the research works on the contamination performance of insulators under low pressure both in home and abroad,and emphatically introduce the recent research achievements in the field in China.It is found that the influence of pressure on the contamination flashover voltage can be evaluated by aexponent n.A statistic analysis shows that the average value of n is 0.49 for suspension insulators and 0.48 for post insulators under AC condition while the corresponding values are 0.27 and 0.42,respectively,under DC condition.A further discussion about the mechanism of pollution flashover voltage decrease under low pressure is presented.It is believed that the decrease of AC U-I characteristic and the arc bridging among sheds are the main reasons for the decrease of the voltage.Then,the physical meanings of the characteristic parameters n and K which demonstrate the influence of pressure and altitude are discussed.It is concluded that the parameter K has a definite physical meaning.Finally,the degrees of altitude affecting the corona inception voltage,air gap breakdown voltage and pollution flashover voltage are compared,and the results show that the decrease degree of pollution flashover voltage is not the most serious if the shed profile is reasonable.

关 键 词：低气压 高海拔 绝缘子 污闪 外绝缘 气压下降指数 海拔修正系数 

分 类 号：TM855[电气工程—高电压与绝缘技术]