500/220kV同塔四回线路的耐雷性能研究

为准确评估500/220 kV同塔混压四回输电线路的耐雷性能,在采用改进电气几何模型(EGM)与电磁暂态程序(EMTP/ATP)计算其绕、反击跳闸率后分析了避雷线保护角、杆塔呼称高度、地面倾角等对5002、20 kV线路绕击耐雷性能的不同影响及杆塔呼称高度、接地电阻、耦合地线架设方式等对500、220 kV线路反击耐雷水平的不同影响。计算结果表明,同塔混压四回线路中不同电压等级线路防雷击侧重点不同,即500 kV线路绕击相对严重,220 kV线路反击相对严重。最后提出了改善线路雷电性能、降低雷击跳闸率的措施,在实际工程中,建议从降低杆塔呼称高度、采用负保护角以及架设耦合地线等方面综合考虑。

Lightning Performance of Quadruple-circuit Transmission Line with Dual Voltage 500/220 kV on the Same Tower

The lightning performance of quadruple-circuit transmission line with dual voltage 500/220 kV on the same tower is calculated and analyzed with EGM(Electro-geometrical Model) and EMTP(Elector-Magnetic Transient Program).And the effects of fielding angle,nominal height of the tower,ground elevation,grounding resistance and the way of laying additional shield wires are discussed in detail.In accordance with 500 kV and 220 kV transmission lines on the same tower,the results show that the priority is different for improving lightning performance,namely,the shielding failure is relatively serious for 500 kV transmission line,and the back flashover is relatively serious for 220 kV transmission line.Finally,several special methods that may be used to improve or degrade lightning performance are presented,such as reducing nominal height of the tower,using negative fielding angle and setting up additional shield wires.