关于10kV交流线路用外间隙避雷器选型现象的一些建议  

Some Explanations About the Chaos in the Selection of EGLA for 10 kV AC Lines

作　　者：王陆璐 黄佳瑞 左中秋 孙泉 张搏宇 吴成成 WANG Lulu;HUANG Jiarui;ZUO Zhongqiu;SUN Quan;ZHANG Boyu;WU Chengcheng(China Electric Power Research Institute,Wuhan 430074,China;Xi'an High Voltage Apparatus Research Institute Co.,Ltd.,Xi'an 710077,China)

机构地区：[1]中国电力科学研究院有限公司,武汉430074 [2]西安高压电器研究院股份有限公司,西安710077

出　　处：《电瓷避雷器》2024年第5期39-46,共8页Insulators and Surge Arresters

摘　　要：为了厘清当前行业中出现的一味提高外串联间隙避雷器本体额定电压值、压缩残压值,混淆本体故障后的工频湿耐受电压要求,以及在带间隙避雷器上配合使用脱离器等现象,以理论分析结合试验论证的方式说明了:1)典型10 kV带外间隙避雷器额定电压13 kV能够满足避雷器自身安全性需求,一味地增加额定电压并不能显著提高避雷器的耐大电流冲击能力,还会影响与间隙性能间的配合;2)典型的10 kV带外间隙避雷器残压值40 kV能够满足线路防雷需求,并有较大的裕度,苛刻的提高残压要求值并无意义;3)线路避雷器的本体故障时EGLA工频湿耐受电压要求值应为不低于系统的最高工频过电压的1.2倍,而非简单的套用“1.2倍额定电压”的表述来计算;4)在外串联间隙线路避雷器上串联脱离器企图实现“双保险”的思路不科学。线路避雷器的外串联间隙已实现了本体故障情况下的隔离功能,并且避雷器的工频续流也在半个周波内能够遮断,不存在脱离器动作的短路电流及其持续时间的工况。随意在线路避雷器上串联脱离器反而占用输电走廊资源,增加线路防雷成本,徒增线路运维负担。In order to clarify the current industry blindly increase the rated voltage value and compression residual voltage value of the series varistor unit of EGLA,confuse the power frequency wet withstand voltage requirements after the SVU failure,and use the disconnector in conjunction with the EGLA.It is explained in the way of theoretical analysis combined with experimental demonstration:Firstly,the rated voltage of a typical 10 kV externally gapped line arrester of 13 kV can meet the safety requirements of the arrester itself.Blindly increasing the rated voltage cannot significantly improve the surge arrester's ability to withstand high current impulse,and will also affect the coordination with the gap performance.Secondly,the residual voltage value of a typical 10 kV externally gapped line arrester of 40 kV can fully meet the lightning protection requirements of the line,and which has a large margin.It is meaningless to increase the residual voltage requirement value.Thirdly,the EGLA power frequency wet withstand voltage requirement value should not be lower than 1.2 times the highest power frequency overvoltage of the system when the body of the SVU fails.It is not simple to apply the expression"1.2 times the rated voltage"to calculate.Fourthly,it is unscientific to try to achieve"double insurance"with the disconnector on the EGLA.The series gap of the line arrester has realized the isolation function under the condition of the SVU fault,and the power frequency freewheeling current of the arrester can also be interrupted within half a cycle,and there is no short-circuit current and its duration of the disconnector action.Arbitrarily connecting the disconnector in series with the line arrester will occupy the resources of the transmission corridor,increase the line lightning protection cost,and increase the line operation and maintenance burden.

关 键 词：EGLA 额定电压 残压 工频耐受电压 

分 类 号：TM862[电气工程—高电压与绝缘技术]