Since 2011

330 kV line in Ningxia has repeatedly occurred bird fault tripping

a serious threat to the safeand stable operation of Ningxia power grid. There is still a lack of research about the guano flashover mechanism of 330 kV line and its factors at home and abroad. This paper firstly studied the hydrophobic property of contaminatedsilicone rubber in low temperature environment pollution. Then based on the relationship between the maximum con-tinuous length and guano parameters during the drop of guano

this paper studied the influence of drop way

dropchannel

conductivity

viscosity

volume

drop position and relative humidity on the flashover characteristic of 330 kV composite insulators in contaminated laboratory. The test results showed that the flashover probability of 330 kV com-posite insulator increases with the decrease of distance and the increase of guano. The flashover probability of guanoescaped from cross arm is lower than not escaped

and the insulators have higher flashover probability when with coro-na ring than that without corona ring. When the guano volume

conductivity

and the air relative humidity are large

the probability of occurrence of flashover is greater.