超高压交流/特高压直流同塔多回输电线路塔宽及离子流对带电作业间隙放电特性的影响  

Influence of Tower Width and Ion Current Density on Live-working Gap Flashover Characteristics of EHVAC/UHVDC Transmission Line on the Same Tower

作　　者：刘庭[1,2] 胡毅[2] 刘凯[2] 彭勇[2] 肖宾[2] 吴田[2] 

机构地区：[1]武汉大学电气工程学院,武汉430072 [2]中国电力科学研究院,武汉430074

出　　处：《高电压技术》2012年第12期3261-3267,共7页High Voltage Engineering

基　　金：国家电网公司科技项目(SG0956)~~

摘　　要：超高压交流/特高压直流同塔多回输电线路下层500kV交流导线平行处的塔身宽度(简称塔宽)比单一500kV线路铁塔增大1倍以上,同时下层带电作业间隙还存在着上层±800kV直流线路产生的离子流。为此,试验分析了"等电位作业人员-塔身"典型作业工况下,1.4～11.0m不同塔宽下空气间隙的操作冲击放电特性,并开展了0.80～1.25m间隙距离下离子流密度对空气间隙操作冲击放电电压影响的试验研究。研究结果表明,随着塔宽的增大,相等带电作业间隙距离的操作冲击放电电压相应降低;当作业间隙距离为7.5m时,11m塔宽下的操作冲击50%放电电压比1.4m塔宽下降低了约14%;在0～167nA/m2离子流密度范围内的离子流对0.80～1.25m间隙距离的空气间隙操作冲击放电电压无影响。该试验研究结果可以为超高压交流/特高压直流同塔多回输电线路带电作业工作的开展提供技术依据。The transmission line which consists of extra high voltage alternating current{EHVAC） and ultra high voltage direct current （UHVDC） on one tower differs from that of single variety or voltage grades, and its tower width, which is paralleled to the 500 kV line, is twice as more as that of the single 500 kV towers, having an ion flow in the lower operation gaps caused by ± 800 kV DC transmission line above. Therefore, based on typical ＂equipotential worker-tower＂ situation, the flashover of the operation gap under switching overvoltage with tower widths of 1.4~11.0 m was researched, and the influence of the ion current density at a distance of 0. 8~1.25 m on the flashover voltage was also experimentally studied. Based on field records and experimental results, it is concluded that, with the increasing tower width, the switching induced {lashover voltage decreases at the same operating distance： when the distance is 7.5 m and the tower width is 11 m, the switching induced 50~/6o flashover voltage is about 14% lower than that with a tower width of 1.4 m. Within a range of 0~167 nA/m2, the ion current density has hardly any effect on the 0.80~1.25 m air gap switching impulse flashover voltage. The results can be considered as a reference for live-working on the EHVAC and UHVDC consisted lines.

关 键 词：超高压交流(EHVAC) 特高压直流(UHVDC) 带电作业 塔宽 离子流密度 放电特性 

分 类 号：TM855[电气工程—高电压与绝缘技术]