1000kV交流同塔双回路多根地线的绕击防雷保护

Lightning Shielding Failure Protection of Multi-band Lightning Wires on 1000 kV AC Double Circuit Line

利用EGM击距作图法解释了1998年—2004年日本特高压双回线路上、中、下导线的雷电绕击率依次减少的现象。为了使1 000 kV双回输电线路更加安全可靠地运行,以国内某1 000 kV交流输电线路工程SZC301型双回直线塔模型为研究对象,并且上、中、下横担均挂导线V形串,分雷电流15 k A、30 k A两种情况,并在平地、地面倾角20°条件下,采用EGM击距法,分析了上、中、下横担各挂地线情况下的绕击保护范围,从而得出在防绕击雷方面下横担挂地线较优的结论。

By using EGM method, the phenomenon that lightning shielding failure rate of the three phase conductor from above to below is reduced in proper order on the UHV double-circuit transmission line from 1998 to 2004 in Japan is explained. In order to make the UHV double-circuit transmission line operate more safe and reliable, taking the SZC301 double circuit tangent tower of domestic 1 000 kV AC transmission line project as research object, and the ＂V＂ strings are suspended on three phase conductor cross-arms, it is divided into two cases which are 15 kA and 30 kA of lightning current under the condition of level ground and incline angle of 20 degrees, the scope of lightning shielding failure protection of the three cross arm installing lightning wires are analyzed respectively by using EGM. The conclusion is summarized that the lightning wire installed below cross arm is better in lightning shielding failure protection.