输电线路雷击跳闸率分级评估方法研究

Study on Grading Assessment Method of Lightning Trip-Out Rate of Transmission Lines

雷击跳闸对电网的安全运行和供电可靠性构成了严重威胁。介绍了输电线路雷击跳闸率的理论值和实际值计算方法,提出了雷击跳闸率分级评估方法,并应用于工程实际。结果表明:采集精确的地闪密度数据,准确计算输电线路雷击跳闸率是雷击风险评估的重要基础;雷击跳闸评估可采用雷击跳闸率与线路雷击跳闸率指标的对比方法,风险级别分为4级;浙江220 k V楠丽线133基杆塔中,70%的杆塔雷击跳闸风险等级为C级及以上,建议优先进行防雷改造。

The lightning trip-out rate has seriously threatened the safe operation and reliable power transmission of power grid. Introduction was made to the theoretical values and actual calculation methods of lightning trip-out rate in transmission lines. This paper put forward the grading evaluation method of lightning trip-out rate and put it in the real project application. The result shows that the accurate acquisition of flash density data and the right calculation of lightning trip-out rate is the key foundation for risk assessment. Lightning trip-out rate grading assessment could be performed by comparing the indexes between the lightning trip-out rate and the lightning line trip-out rate and the level of risk is divided into four grades. Taking the level of risk of 133 base towers in 220 kV transmission line of Nanli in Zhejiang province as an example, 70% of them is C-level or above. It is concluded that lightning protection transformation should be carried out in priority.