山区110kV线路雷击事故分析及对策

Analysis of the Lightning Strike Fault of 110kV Transmission Line in Mountainous Area and Counter Measures

通过对山区送电线路雷害事故的分析,得出了山区雷害主要是雷击杆塔或避雷线造成的反击事故。雷击事故主要发生在水库、水塘附近的突出山顶上;高山的山坡或半坡向阳的山脊上;电阻率高的土壤区和附近无树木等山丘突出处。地形坡度较陡的杆塔外边侧绝缘子、大转角杆塔外侧绝缘子串和大档距两端杆塔也易遭雷击闪络。采取杆塔降阻、装设线路避雷器、侧向避雷针和加强绝缘等多种措施后,防雷保护效果较好。

At summarizing lightning accidents of transmission lines in mountainous areas it was concluded that the lightning accidents were mainly caused by inverse flashover of lightning strike on tower. The lightning accident occurred at mountain peak near water reservoirs, slope of high mountain or sunny ridge of mountain slope, soil region with high resistivity and treeless protruding peak. Moreover, outer insulator string on tower at steep slope or on corner tower as well as towers of great span were easily suffered from lightning strikes. The lightning protection could be improved by means of decreasing grounding resistance of tower, installing line type surge an＇ester and side lightning rod as well as increasing the insulation level.