随机参数对同塔双回输电线路雷击跳闸过程的影响

同塔双回输电线路较之电压等级相同的单回输电线路具有导线数量多、杆塔高度高等结构特点,更易发生雷击故障。为了深入研究同塔双回输电线路雷击跳闸机理,结合忻州地区实际线路数据,基于Monte Carlo法这一随机数学方法建立了适用于同塔双回输电线路的雷击跳闸率仿真流程,并对其随机参数产生的影响进行了深入探讨,比较分析了单、双回输电线路雷击跳闸率受随机参数影响的敏感程度。结果表明,较之同电压等级下单回输电线路,双回输电线路对雷击部位更为敏感,其绕击跳闸率随地面倾角增加而增加的幅度更大;在考虑工频叠加电压后,单、双回输电线路反击跳闸率均有显著提高,地面倾角较大的情况下单回输电线绕击跳闸率略微减小,而双回输电线路绕击跳闸率则有明显增大。

Effects of Random Parameters on the Lightning Flashover of Double-circuit Transmission Line

Compared to single-circuit transmission line with the same voltage level,double-circuit transmission line has higher probability of lightning flashover,which is caused by structural characteristics,such as the more numbers of conductors,the higher tower-body,etc.In order to study the characteristics of double-circuit transmission line lightning flashover,according to engineering data collected from transmission lines in Xinzhou,Shanxi province,we established a simulation process applied to the double-circuit transmission line lightning flashover by the random mathematical method of Monte Carlo.The effects of random parameters in this process were discussed,and the different sensitivities to these parameters of double-circuit and single-circuit transmission line lightning flashover rate were compared.The results show that,compared to single-circuit transmission line with the same voltage level,double-circuit transmission line is more sensitive with lightning striking position,and the shielding failure flashover rate increases more quickly as the obliquity on the ground increases.After taking the power frequency voltage into consideration,the back flashover rates of double-circuit and single-circuit transmission lines are significantly increased.And with the high obliquity on the ground,the shielding failure flashover rate of single-circuit transmission line is decreased appreciably,and that of double-circuit transmission line is increased obviously.