负角保护针的防雷电绕击效果研究

Research on Effect of Lightning Shielding Failure Protection of Negative Angle Protective Pin

为评估在杆塔上安装负角保护针的防雷电绕击效果,建立三维电气几何模型实现对安装负角保护针后输电线路的雷电绕击跳闸率的计算,并分析负角保护针的安装位置、安装角度和长度对防雷电绕击效果的影响。对220 kV 典型单双回线路杆塔的防雷计算结果表明：对于单回线路,负角保护针宜安装在导线横担处,安装角度为0°（即水平放置）,长度取2~3 m,安装后可将输电线路绕击跳闸率降低10%左右；对于双回线路,负角保护针宜安装在中相导线横担处,安装角度为0°,长度取2~3 m,安装后可将输电线路绕击跳闸率降低10%~15%。

In order to evaluate effect of lightning shielding failure protection of installing negative angle protective pin on the tower,a 3D electrical geometrical model （EGM）was established for realizing calculation on lightning shielding failure trip rate of power transmission lines after installing negative angle protective pin. Meanwhile,impact on effect of lightning shielding failure protection by installation position,installation angle and length of the negative protective pin was analyzed. Calculation result of lightning protection on tower of 220 kV typical single and double circuit line indicated that to the single circuit line,it was suitable to install the negative protective pin on the cross arm of conductor,the installation angle should be zero degree （means horizontal）and the length should be 2~3 m. The shielding failure trip rate of power transmission line could be reduced by about 10% after installation of the negative angle protective pin. To the double circuit line,it was suit-able to install the negative angle protective pin on the cross arm of middle phase conductor,the installation angle should be zero degree and the length should be 2~3 m. The shielding failure trip rate could be reduced by about 10%~1 5%.