Analysis of Lightning Performance of Overhead Transmission Lines with Insulator Parallel Gaps

Lightning is one of the major threats to the operation of high voltage overhead transmission lines. To improve the lighting performance of overhead transmission lines, various lighting protection measures are used. The major challenge in choosing lightning protection measures is that it's difficult to quantitatively evaluate how these measures changes the lightning performance of the transmission lines. Parallel gap is used to protect insulator from the arc caused by lightning discharge. Based on a large-scale insulator parallel gap installation project, this work analyzed relationship between the insulator parallel gap installation and the lighting performance of the transmission lines. This work first proposed a method for evaluation of lightning performance of existing overhead transmission lines, and then the method was applied to groups of transmission lines installed with insulator parallel gaps. Finally, the lightning performance of the transmission lines before and after the installation of insulator parallel gaps are compared and analyzed.