应用灭弧防雷间隙抑制35kV架空输电线路雷击过电压的方法

针对我国南方部分地区35 kV架空输电线路雷击事故严重的情况,设计一种基于"疏导型"防雷理念和"气吹灭弧"相结合的灭弧防雷间隙,该间隙在输电线路发生雷击时能优先于绝缘子串闪络,将雷电流导入大地的同时熄灭工频续流。通过小电流灭弧特性试验和仿真建立的灭弧防雷间隙的PSCAD仿真计算模型,针对广西大化县35 kV架空输电线路的仿真计算结果和实际运行情况表明,输电线路安装灭弧防雷间隙可有效抑制雷击过电压,降低线路的雷击跳闸率。

An Approach to Suppress Lighting Overvoltage of 35 kV Overhead Transmission Lines by Air-Blast Arc-Quenching Gap

In allusion to serious situation that the faults caused by lightning stroke frequently occur in 35 kV overhead transmission lines in part of South China,an air-blast arc-quenching gap based on the "scatter" thinking of lightning protection is designed.When lightning strikes on overhead transmission line,the designed air-blast arc-quenching gap can flashover prior to the flashover of insulator string and the power frequency afterflow will be quenched while the lightning current is being flowed into ground via the designed gap.Based on the testing data from small-current arc-quenching property tests of the designed gap and simulation results,a PSCAD model of the designed gap is built,and the simulation results of 35 kV overhead transmission line located in Dahua county,the Guangxi Zhuang Autonomous Region as well as the actual operation effect of the gap show that lightning overvoltage can be effectively suppressed by installing the designed gap on 35 kV overhead transmission lines,thus the lightning trip-out rate of overhead transmission line can be decreased.