Geography´s Influence on Max Shielding Failure Lighting Current of Transmission lines

The landform of transmission lines corridor has great influence on the max shielding failure lightning current. This paper aims to revalue the height of the conductor and the overhead ground wire in the electric geometry model (EGM), and to displace the real height. Taking the case of 500kv transmission lines as an example, the results show that it is probable to distinguish the easy strike tower by this method. The max current increases greatly where the tower passes the mountain valley, so the probability of flashover enhances; and when the ground elevation is bigger, the max current is smaller, while when the absolute values are equal, the current of the minus ground elevation is greater.