Research on characteristics of conductor surface electric field considering downward lightning leader

Shielding failures of lightning is a key problem for the reliable operation of transmission lines. The Leader Progression Method (LPM), based on the theory of long air ^{gap discharge}, is an advanced method to evaluate the shielding failure probability of transmission line nowadays. The calculation of surface electric field on phase conductors and ground wires is the key factor that influences the upward leader inception. In this paper, the operation voltage of transmission line, the distance between adjacent check points set on the surface of transmission lines and some other factors that influence the surface electric field were analyzed. The influence of these factors on surface electric field was presented in this paper.