500kV交流输电线路组合绝缘子串试验分析

Test Research on Insulator String with Various Materials for 500kV AC Transmission Line

为系统研究500 kV交流线路复合绝缘子和盘形绝缘子组合绝缘子串配置的电压分布,给工程设计提供参考,对复合绝缘子两端安装不同片数玻璃绝缘子、采用下沉式和上扛式悬垂线夹、单I串和双I串、有无均压环等组合绝缘子串结构型式进行了大量试验和数值分析研究,提出了一种可使复合绝缘子金属附件连接区避开高场强区域的绝缘子串组合型式。研究结果表明,在相同结构高度下,采用上扛式悬垂线夹,复合绝缘子导线端配5片玻璃绝缘子,可将该组合串中复合绝缘子高压端部最高电压分布由原41%降低至14%;在导线端安装6片玻璃绝缘子,横担端安装1片玻璃绝缘子,可将该组合串中复合绝缘子高压端部最高电压分布由41%降低至11%,导线端盘型绝缘子可免除均压装置,同时绝缘子串的雷电冲击闪络电压也有所提高。

In order to provide a reference to transmission engineering design, the voltage distribution of 500 kV transmission line insulator strings combined with composite insulator and cap and pin glass insulator is studied systematically. The different combination of insulating structure type is discussed by lots of potential distribution computation and measurement tests, including linking different pieces of glass insulators at the end of composite insulator, using sunken and carry type of suspension clamp, single I and double I string, whether using uniformity voltage fitting and so on. The new insulation configuration way is presented, in which the composite insulator can be avoided to operate in the high electric field region. It is shown that the maximum potential distribution of high voltage end fitting part of composite insulator using carry type of suspension clamp is reduced from 41% to 14 %, when the composite insulators link to five glass insulators and keep the same structural height. It is also shown that the maxi- mum potential distribution of high voltage end fitting part of composite insulator using carry type of suspension clamp is reduced from 41 % to 11% , when the high voltage end of composite insulators links to six glass insulators and a glass insulator at the earth side of composite insulator. The lightning impulse flashover characteristics can also be improved.