大理典型密集输电通道雷击特性分析OA

The typical dense transmission lines in Dali area were selected as the research objects.Accord-ing to the actual structure and parameters of the lines,a calculation model of lightning strike overvoltage was established.By calculating the lightning resistance level of each line,the weak sections of lightning protection for the dense lines were obtained.The electromagnetic coupling characteristics of the crossover line and the influence of the upper line on the lower crossover line under the lightning strike conditions were analyzed.The shielding effect of lightning between adjacent lines was studied,and the shielding failure trip-out rate of compact parallel lines was calculated considering the lightning shielding effect.The result shows that the lightning resistance level of each line is quite different due to the influence of the grounding resistance of the tower.When the lightning strikes the upper Yangli Ⅰ line,it will not cause the flashover trip of the lower crossover Jianhe line.When the distance between the Jianhe line and Yang-he Ⅰ line is 40 meters,considering the lightning shielding effect,the lightning trips are reduced by 52.18％and 41.2％respectively.