大理典型密集输电通道雷击特性分析

Lightning Strike Characteristics of Typical Dense Transmission Lines in Dali

选取大理地区典型密集输电通道为研究对象,根据线路实际结构及参数,建立了雷击过电压计算模型,通过计算各线路的耐雷水平,获得了密集线路的防雷薄弱段;分析了交叉跨越线路的电磁耦合特性,以及雷击上层线路时对下层交叉跨越线路的影响情况;研究了临近线路之间的雷电屏蔽效应,计算了考虑雷电屏蔽效应后紧凑并行线路的绕击跳闸率。结果表明:由于杆塔接地电阻的影响,各线路的反击耐雷水平差异较大;雷击上层羊丽Ⅰ回线时,不会造成下层交叉跨越线路剑鹤中线闪络跳闸;当剑鹤中线和羊鹤Ⅰ回线线路段的间距为40 m时,考虑雷电屏蔽效应后,绕击跳闸率分别降低了52.18%和41.2%。

The typical dense transmission lines in Dali area were selected as the research objects.According 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 YangliⅠline,it will not cause the flashover trip of the lower crossover Jianhe line.When the distance between the Jianhe line and Yanghe I line is 40 meters,considering the lightning shielding effect,the lightning trips are reduced by 52.18%and 41.2%respectively.