摘要
为得到隔雨伞对染污交流空心套管大雨闪络特性的影响规律,通过模拟试验进行了研究。试验采用5m长、不同伞形的表面脏污瓷空心套管,模拟了大雨条件下这些套管的闪络,获得了套管的闪络特性。同时对套管在淋雨状态下,施加电压后电弧起始、发展、直至闪络或耐受的全过程,以及同步的泄漏电流典型特征进行了分析。结果表明:在爬电距离相近条件下,装有4片隔雨伞和8片隔雨伞的套管最大淋雨耐受电压分别比无隔雨伞时提高了72.7%和127.3%;隔雨伞的存在影响了套管湿润状态、分隔雨帘的形成并阻挡了电弧的串接,使泄漏电流从0增大至最大值或至闪络的时间减小;隔雨伞能够大幅度提高套管在大雨情况下的耐受电压。以上情况也说明,在选择套管或支柱的户外绝缘时,爬电距离不能作为唯一的标准。
To understand the effect of water-cut sheds on flashovers of contaminated hollow core insulators in heavy rain, we performed simulative experiments. Taking 5-meter-long hollow core porcelain insulators for examples, we experimentally simulated flashovers on the samples in heavy rain, and measured the characteristics of the flashovers. Moreover, we analyzed the whole arcs propagating process, including the processes of initiating, developing, and flashover or withstand, under the test conditions, as well as the typical features of leakage current changes synchronously with arcs. The tests show that, with similar creepage distances, insulators in the presence of 4 water-cut sheds and 8 water-cut sheds have maximum withstand voltages averagely 72.7 % and 127.3 % higher than those in the absence of water-cut sheds, respectively. Adding water-cut sheds would influence insulator wetting, cut raining bridges and impede arcs from bridging, and it also accelerates leakage current growing from zero to maximum or turning into flashover. It is concluded that water-cut sheds significantly enhance the withstand voltage of bushing under heavy rain. The results also indicate that when bushings or post insulators are chosen for outdoor insulation, the creepage distance of equipment should not be the only criteria.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2013年第12期2980-2986,共7页
High Voltage Engineering
基金
国家重点基础研究发展计划(973计划)(2011CB209406)~~
关键词
空心套管
大雨
闪络
超
特高压交流
泄漏电流
湿润
电弧
hollow core insulators
heavy rain
flashover
EHV/UHV AC
leakage current
wetting
electric arc
