Comparison of numerical analysis models for shielding failure of transmission lines

The shielding failure is the occurrence of a lightning stroke that bypasses the overhead shielding wires and strikes on the phase conductors. The accurate design to improve the shielding effect of transmission line to lightning is one of key problems in transmission line design. Some numerical analysis models for analysis of shielding failure performance were proposed and discussed, mainly including the traditional electrogeometric model (EGM) and improved EGM, the leader progression model (LPM). The paper compares the results of lightning current range and location region for shielding failure by numerical calculation applying the three models. The influence of ground slope angle and voltage class of transmission line is also taken into account.