Experimental Research on Lightning Influence of 500kV Transmission Lines in Complex Terrains

Abstract

This paper presents the lightning influence of complex mountainous terrains in 500kV transmission lines and the corresponding methods to improve lightning withstanding level for the safety and stability of power system. According to the general situations and space distributions of lightning activities in East China, that is, mountainous areas are more serious than plains. Four groups of discharging experiment are conducted by the construction of solid models that simulate transmission line routes in mountains. Meanwhile, some commonly used effective methods are studied in detail to reach a conclusion that the lateral rod can reduce shielding rate most efficiently. Then the operation principles and effect factors of lateral rods are analyzed theoretically through the establishment of Electro-geometric Model (EGM), and a large number of repetitive discharging tests are also executed to count and calculate the experimental shielding rates. Experimental results indicate that different terrains have a significant influence mostly on the lightning shielding rate of lines. The lateral rod can largely reduce the shielding rate and the protection effects are influenced by the rod length and angle. The conclusion obtained corroborates the theoretical analysis, which can be widely used as reference in practical applications and lightning protection transformation assessments