扇形不均匀污染支柱绝缘子的交流闪络特性  

AC Flashover Performance of Post Insulator With Fan-shaped Non-uniform Pollution

作　　者：张志劲[1] 向缨竹 乔新涵 蒋兴良[1] 武剑 ZHANG Zhijin;XIANG Yingzhu;QIAO Xinhan;JIANG Xingliang;WU Jian(State Key Laboratory of Power Transmission Equipment&System Security and New Technology(Chongqing University),Shapingba District,Chongqing 400044,China;State Grid Chongqing Maintenance Company,Gaoxin District,Chongqing 400039,China)

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆市沙坪坝区400044 [2]国网重庆市电力公司检修分公司,重庆市高新区400039

出　　处：《中国电机工程学报》2019年第24期7385-7393,共9页Proceedings of the CSEE

基　　金：国家电网公司科技项目资助(2018渝电科技17#)资助项目(SGCQJX00YJJS1900591);重庆市研究生科研创新资助项目(CYB18010)~~

摘　　要：支柱绝缘子在地形或单向风等因素的影响下易累积形成扇形不均匀污秽,背风侧通常较迎风侧受污染更加严重。对支柱瓷绝缘子进行不同扇形不均匀污染条件下的人工污秽交流闪络试验,讨论扇形不均匀污染对闪络电压、闪络过程、背风侧污层电导率和绝缘子表面电导的影响。试验结果表明,支柱绝缘子在这种不均匀污染下的交流闪络性能与均匀污染下有很大差异,不均匀污秽下的支柱绝缘子闪络电压很大程度上受附盐密度(salt deposit density,SDD)、迎风侧与背风侧的SDD比值(Y/B)以及背风侧面积占总面积之比k的影响。Y/B从1/1降至1/8时,闪络强度下降约16%,k从25%上升至45%时,闪络电压小幅上升;SDD与Uf之间的关系仍可以用负指数函数表示,且扇形非均匀污染对其影响主要在于改变比例系数a,而非指数n。为了进一步分析,还建立一种不均匀污秽下的绝缘子表面污层电导计算模型,并计算得到不同Y/B和k时不均匀污秽与均匀污秽下的表面污层电导之比?的理论值,结果与试验数据规律吻合。这从理论上证明了扇形不均匀污染会导致绝缘子的表面污层电导变大,从而促进电弧传播和闪络过程,最终降低闪络电压。Affected by certain factors, such as unidirectional wind or landform, post insulator surface will easily get coated with fan-shaped non-uniform pollution. To put it another way, leeward sides of post insulators are usually covered with thicker pollution layers. In this paper, AC artificial pollution flashover tests on porcelain post insulator with fan-shaped non-uniform pollution were carried out under various polluted conditions. The influences of fan-shaped non-uniform pollution on flashover voltage, flashover process, surface layer conductivity of leeward side and surface contamination layer conductance were discussed. Test results indicate that there is a huge distinction between AC flashover performances of post insulator under non-uninform pollution and uninform pollution. The flashover voltage of post insulator with non-uninform pollution is largely influenced by salt deposit density(SDD), the ratio of SDD of windward side to leeward side(Y/B) and the occupation ratio of leeward side k. A reduction of Y/B from 1/1 to 1/8 would give a decrease of 16% in flashover strength. Flashover voltage may rise slightly when the occupation ratio(k) of leeward side increases from 25% to 45%. Uf can still be calculated by a negative exponential function of SDD, and the effect of fan-shaped non-uniform pollution on Uf-SDD relationship mainly lies in changing the proportionality coefficient a rather than the exponent n. A surface contamination layer conductance calculation model of non-uniform polluted insulator was established for further analysis. The theoretical ratio of surface contamination layer conductance under non-uniform and uniform pollution ? is calculated by different Y/B and k, which agrees well with experiment data. It is theoretically proved that fan-shaped non-uninform pollution will lead to an increase in surface contamination layer conductance of post insulator, which promotes the arc propagation and flashover process, and finally lowers flashover voltage.

关 键 词：支柱绝缘子 扇形不均匀污秽 交流 表面污层电导 

分 类 号：TM852[电气工程—高电压与绝缘技术]