To study the flashover performance of insulator for overhead transmission line under typical bird contamination conditions

we put forward an artificial contaminating method to simulate the insulator contamination of bird excretion based on the typical morphology and parameters of contaminated insulator string. Artificial pollution tests were carried out to investigate the insulator string of 110 kV and 220 kV AC transmission lines with additional bird con-tamination stimulant liquid considering the different environmental pollution levels. The tests show

under the different flashover voltages and variant contaminated conditions and in the regions of slight pollution

contaminant flashover will not occur for the string of 9 discs used in 110 kV AC transmission line and the string of 15 discs used in 220 kV AC transmission line. Those results of tests provide references for the analysis of bird-related outage and the selection of prevention measures.