Discharge Characteristics of Tower-line Air Gap of AC Transmission Line Caused by Bird Streamer

In order to avoid discharge in tower-line air gap under the influence of bird streamer(bird excretement), we composed a solution according to the electric conductive and viscosity of bird streamer, and then obtained the characteristics of AC discharge in tower-line air gap under the influence of bird streamer through experiments using the solution. Moreover, based on the current field theory, the electrode breakdown model of simplified tower-line is established using finite element simulation software COMSOL Multiphysics. The results show that, when a big bird excretes at the cross-arm of a tower, the streamer can reduce the breakdown voltage of tower-line air gap by 75%,because the electric field strength in the gaps between the end of bird streamer and the two high voltage ends of line increases greatly, which would distort the air-gap electric field severely and cause breakdown in the air gap.