单避雷线在输电线路防雷中的应用探讨

通过对110 kV及以上输电线路跳闸事故的统计分析,得出雷击是输电线路跳闸的主要原因。根据雷电活动情况、雷击跳闸情况及国网公司架空输电线路差异化防雷指导意见,对架空输电线路单、双避雷线运行情况进行比较分析,对架空输电线路差异化防雷设计进行了研究,并结合实际提出了有针对性的防雷措施:110 kV线路采用单避雷线时,工程的总体投资可以减少2%~4%;采用单避雷线后,地线支架安装在塔身之上,与双避雷线相比,增强杆塔抗扭性,提高了对冰灾、舞动、大风等突发自然灾害的抵抗力,从而提高了线路的安全性;平原地区,雷电活动偏少,绕击雷极少,雷击跳闸次数较低,开展110 kV架空输电线路单避雷线运行是可行的;对于双回路110 kV线路,导线可以采用"V"形串设计,以减小单避雷线的保护角,降低线路绕击跳闸率。

Application Discussion on Single Lightning Conductor in Transmission Line Lightning Protection

Based on statistics analysis of the 110 kV and above transmission line trip accident,it is indicated that the lightning stroke is the main cause of transmission line trip.According to the lightning activity,lightning trip and the differential lightning protection directive opinion for network overhead transmission line by the State Grid Corporation of China,comparative analysis are carried out on the operation condition of single or double lighting conductor for overhead transmission line,and the corresponding lightning protection measures are proposed combined with the actual:when 110 kV line using single lightning conductor,the overall investment of the projects can be reduced by 2%-4%;grounding line bracket is installed on the tower body when single lightning conductor is used.Compared with the double lightning conductor,pole torsion resistance is enhanced,the sudden natural disaster resistance of ice disaster,dancing,gale,is improved,thereby improving the line safety;in the plain areas,lightning activity are little,shielding lightning is few,lightning trip frequency is low,so it is feasible to carry out the single lightning conductor operation of 110 kV overhead transmission line;for double loop 110 kV line,"V" shape string design of the conductor can be used,to reduce the protection angle of single lightning conductor,and reduce line shielding trip-out rate.