Researches On 35kV Country Power System Of The Lightning Protection

Qinan substation is located in the south of Chongqing and most of service regions are in the country. Most of transmission line is 35kV and single line, the line corridor of the country power system is in the mountainous area with high soil resistivity, complex landform and bad environment, that cause power supply reliability low. So it's difficulty to the lightning protection for the transmission lines. The operation data in recent years reveals that the accidents which caused by lightning striking are percent 50 to 70 in all accidents which caused by lightning striking. So it was worth studying synthetic lightning protection measures on demonstration of the situation of the Qinan Bureau's 35kV lines.According to the former conditions, study of 35kV lighting withstand level is meaningful to practice project. This article bases on the lighting protect situation of Qinan area, analyzes the lighting reasons through electric parameter, transmission lines and substation single phase capacity, and analyzes the are suppressing coil operation. With the demonstration of 35kV line of Qinan substation, it built a numeral value calculation model of on-line data of each pole with EMTP program. Find out some factors of causing lines to outage frequently and the measures how to improve lightning withstand level of lines and decrease the lightning tripping outage of transmission line.According the research, summarizing the main reason of causing lighting tripping outrage, giving the decreasing lighting tripping outrage synthetical method through decreasing tower grounding resistance, applying arc suppression coil suitably and installing line MOA on the easily striken towers.