输电线路杆塔接地电阻对线路反击跳闸率影响研究

Study on Influence of Grounding Ｒesistance of Transmission Line Tower on Counterattack Trip － out Ｒate

摘要:

随着输电线路建设运行规模的不断扩大，同一走廊的输电线路杆塔包含不同类型的塔头，从而导致杆塔不同 类型塔头可能处于不同大气环境和土壤环境中，其接地电阻存在很大差异，因此有必要对不同塔头类型的杆塔在不 同接地电阻值下的耐雷水平和反击跳闸率影响进行研究。建立了猫头塔、酒杯塔、鼓型塔等 3 种 500 kV 交流输电线 路杆塔的反击闪络模型，并研究了 3 种塔头模型的杆塔接地电阻对线路反击耐雷性能的影响规律: 酒杯塔与鼓型双回 闪络规律类似，对鼓型单回闪络线路的影响最大，其次是鼓型双回闪络线路和酒杯塔，影响最小的是猫头塔。

关键词:猫头塔; 酒杯塔; 同塔双回鼓型塔; 接地电阻; 反击跳闸率

Abstract:

Due to the expansion of EHV/UHV transmission lines，the probability of lightning strike on the line is increased， and the tower of the same line may be in different working environment． Therefore，it is necessary to study the influence of grounding resistance on lightning resistance performance of the lines． The back － flashover model for three kinds of towers are established，such as cat － head type tower，cup type tower and drum － shaped tower of 500 kV AC transmission lines． The influence regularity of grounding resistance of three models on lightning back － flashover performance is analyzed，that is，the flashover rules of cup type tower is similar to the drum － shaped double － circuit tower，and it has the greatest influence on the drum － shaped single － loop，followed by the drum － shaped double － circuit and the cup type tower，and it has the least influence on the cat － head type tower．

Key words:cat － head type tower; cup type tower; drum － shaped tower of double － circuit tranmsission line on the same tower; grounding resistance; counterattack trip － out rate