线路避雷器在110kV荔茂线60^#杆防雷中的应用

Application of Line Surge Arrester to Lightning Protection on the 60^# Pole of 110 kV Li-Mao Transmission Line

110 kV荔茂线60#杆为大跨越三联杆,A、C相杆的避雷线对B相(中相)导线的保护角为51°时,不起保护作用,使60#杆B相(中相)导线易遭受雷击,造成绝缘子串闪络。为解决60#杆的雷害问题,安装了线路避雷器。对线路避雷器雷击动作后杆塔相邻相绝缘子串的耐雷水平的计算结果表明:线路避雷器除了可防止相绝缘子串遭雷击闪络而引起线路跳闸外,还可利用其雷击动作时向导线分流部分雷电流,从而降低杆塔分流系数,将杆塔相邻相绝缘子串的耐雷水平提高了约7%。近两年的线路运行表明,采用线路避雷器是线路防雷的有效措施。

The 60^# pole of 110 kV Li-Mao Transmission Line is long-span crossing three poles and the protection angle between the lightning conductors of A and C-phase poles and B-phase （middie phase）conductor is θ=51° without the protective role, which causes the B-phase（middle phase） conductor of 60^# pole vulnerable to lightning, resulting in insulator string flashover. In order to solve the lightning accident problem of 60^# pole, line surge arrester has been installed. The result of calculation on the lightning withstand level of adjacent phase insulator strings of the tower after the line surge arrester operation after lightning stroke indicate that the line surge arrester, in addition to prevent the installed phase insulator string from causing line tripping due to lightning flashover, also can share part of lightning current to the conductor during its operation, thus to reduce the lightning sharing coefficient of the tower and enhance the lightning withstand level of the adjacent phase insulator strings of the tower by about 7%. the result of the last two year running of the line shows that, introducing line surge arrester in effective measures of line lightning protection.