考虑输电线路走廊地闪密度的防雷措施效果评估

为使防雷措施的效果评估更加接近工程实际情况,提出采用单位雷击跳闸率评价防雷措施效果的方法.该方法以实际雷电观测数据和输电线路运行记录为基础,将雷击跳闸率归算到同一地闪密度水平,弥补了仿真计算和模型试验需要简化和假设的不足,克服了单纯采用雷击跳闸率指标或仅进行年雷暴日归算的评估方法的片面性.对江西电网输电线路广泛应用的负角保护针、防绕击避雷针分别进行了效果评估.结果标明电压等级越低,防绕击措施所起的效果越弱,并给出了定量评价结果

A Method to Evaluate Effects of Lightning Protection Measures Considering Ground Flash Density in Transmission Corridor

To make the effect evaluation results of lightning protection measures conform closer to engineering reality,it was proposed to evaluate effects of lightning protection measures by specific lightning trip-out rate.Based on observational data of lightning stroke and operation log of transmission lines the lightning trip-out rate was reduced to identical ground flash density level,thus the defects in simplification and assumption necessary for both simulation and model tests could be remedied and the one-sidedness of evaluation methods,in which the index of lightning trip-out rate was adopted merely or only annual thunderstorm day was reduced,was rectified.The effects of lightning protection measures widely applied in Jiangxi power grid such as the lightning rod with negative protection angle and lightning rod for shielding failure prevention were evaluated,and evaluation results showed that the lower the voltage class of transmission line,the poorer the effect of lightning rod for shielding failure prevention would be,in addition,the results of quantitative evaluation were given.