500 kV交流架空输电线路雷电性能及防护措施

Lightning Performance and Protection Measures of 500 kV AC Overhead Transmission Lines

[目的]雷击是造成500 kV交流输电线路故障和停电事故的主要原因,开展输电线路防雷评估对于系统的稳定运行有着极为重要的意义。[方法]依托我国某在建500 kV交流输电线路工程,根据线路基本参数等信息,通过电磁暂态程序(Electro-Magnetic Transient Program,EMTP)和改进的电气几何模型法(Electro-Geometric Model,EGM),对线路的绕击、反击耐雷性能进行了仿真研究,计算了线路的雷击跳闸(闪络)率,按照线路雷击风险划分原则确定线路杆塔的雷击风险等级,结合邻近已投运线路的实际运行数据,针对雷击风险较高的杆塔提出了雷击防护措施,并通过计算进一步验证了措施的有效性。[结果]仿真结果表明,安装线路避雷器是有效的雷击防护措施,它们可大幅降低杆塔的雷击跳闸率,提升线路耐雷性能。在采取雷击防护措施后,全线无雷击风险等级为IV级的杆塔,全线平均雷击跳闸率下降至I级的安全水平,满足《架空输电线路防雷技术导则》(Q/CSG 1107002—2018)要求。[结论]文章所提的雷击风险评估方法和防雷措施选择流程是正确并有效的,对500 kV交流架空输电线路防雷设计具有一定的工程应用价值与参考意义。

[Introduction]A lightning strike is the main cause of failure and outage in 500 kV AC transmission lines,and it is very important to carry out lightning protection assessment for transmission lines for the stable operation of the system.[Method]In this paper,based on a 500 kV AC transmission line project under construction in China,the lightning resistance of the line was simulated and studied using the EMTP(Electro-Magnetic Transient Program)and the EGM(Electro-Geometric Model)and the lightning trip-out(flashover)rate of the line was calculated according to the basic parameters of the line.The lightning risk level of line towers was determined based on the principle of lightning risk classification.Combined with the actual operation data of the nearby lines,lightning protection measures were proposed for towers with higher lightning risk,and the effectiveness of the measures was further verified through calculation.[Result]The simulation results show that the arrester is an effective lightning protection measure,which can significantly reduce the lightning trip-out rate of the tower and improve the lightning resistance of the line.With lightning protection measures,there is no tower with lightning risk level IV on the whole line,and the average lightning trip-out rate of the whole line has dropped to the safe level I,which meets the requirements of Guide for Lightning Protection of Overhead Transmission Lines(Q/CSG 1107002—2018).[Conclusion]The lightning risk assessment method and the lightning protection measures proposed in this paper are correct and effective,and have somewhat engineering application and reference values for the lightning protection design of 500 kV AC overhead transmission lines.