Simulation Of Shielding Failure Flash-Over Of Transmission Line Based On Leader Progression Model

Transmissionline lightning failures threaten safe and reliable operation of power grid. Guangzhou is one of areas with the strongest lightning activities in China. Lightning protection in Guangzhou power grid has reference role to construction and operation of power grid in other places with frequent lighting in China. Therefore, selection of key parameters in leader progression model is studied. Distribution rule of lighting activities and line lighting trip-out in Guangzhou is analyzed; shielding failure features of typical 500kV power transmission line in Guangzhou are analyzed. The study shows that lighting trip-out frequency has certain relevance to cloud-to ground lightning frequency. Operation data show that Guangzhou 500kV line shielding failure flash-over rate is 0.125 times / (100 km.year). Two terrains of plain and mountain are considered. The line shielding failure flash-over rate is 0.108 times / (100 km.year) according to calculation.