Research On The Improvement Of Lightning Protection By Installing Ground Wire Of 10kV Overhead Distribution Line In Qingyuan

10kV overhead distribution lines in China is generally in low insulation level and they are prone to lightning accident.In particular,the mountainous areas with frequent lightning activities,where the accidents caused by lightning accounted for 30% of the entire distribution network.Therefore,to strengthen the network lightning protection and improve the lightning withstand the level of 10 kV distribution line is significant to improve power quality of distribution network,also will ensure the safe operation of the distribution network.This thesis selects Qingyuan city 10 kV overhead distribution line as the research object,which has intense lightning activity and a large number of lightning accident.In Qingyuan city,the existing lightning protection is difficult to conduct lightning protection conditions effectively,so we suggest to propose round wire in the 10 kV overhead distribution lines to improve the lightning protection level.Therefore,according to the topography and the special characteristics of the lightning activity in Qingyuan city,we carry out a feasibility study to improve the lightning protection level by Installation the lightning lines on 10 kV overhead distribution lines.The main work is as follows:1)Collected the statistics in the past 5 years of lightning activity information and lightning in Qingyuan area,analyzed the causes and characteristics of lightning accident produced a district of Qingyuan City.The conclusion is that the lightning activity of Qingyuan city is strong,and the Thunderstorm Day is far more and the lightning density is strong.Among them,the strongest lightning activities are Qingcheng district.2)According to the results of analyzing lightning accident,analyzes the producing mechanism of induction thunder and lightning,and the lightning characteristics in Qingyuan city.3)Selected the 10 kV line of Gao Tian,110 kV station of Shengping to calculation the lightning trip rates before and after the erection of ground wire.In order to calculate the lightning trip out rate,a lightning stroke model of overhead distribution line is established,and the influence of grounding resistance on the lightning adjustment rate after laying the lightning conductor is emphatically analyzed,and the best grounding resistance value of the lightning conductor is obtained.4)To verify the correctness of the theoretical analysis,Qingyuan Power Supply Bureau chooses a 10 kV line of Gao Tian,110 kV station of Shengping to set up a lightning rod as a demonstration line.The actual operation result shows that,after setting up the ground wire,the lightning trip rate has dropped from 17.63 /(100km?year)to 3.346 /(100km?year),which shows that it is feasible to improve the lightning withstand level in the Qingyuan city.The work of this paper shows that Qingyuan city because of its special topography,lightning conductors is an effective method to improve the lightning withstand level of 10 kV,and the analysis of the distribution lines together with grounding resistance will offer some guidance advice for the Qingyuan city in the following construction of the erection of ground wire.