As we all know

freezing water conductivity affects the conductivity of the water film on the surface of ice-covered insulator

which causes a substantial decrease in flashover voltage. However

little research focuses on the special distribution of conductivity in the ice layer and icicle. Energized icing and non-energized icing experiments on 3 units of XP

4

-160 insulator string were carried out in the artificial climate chamber. Combining with simulation analysis and molecular polarization theory

we found that

due to the electric field

the influence of molecular polarization

the leakage current

and corona discharge

the tip of icicle with a smaller diameter and a shorter length will bend toward the axis of insulator string under the energized condition. After the desired ice thickness

the ice layer and icicles are melted separately under constant temperature environment

their conductivity is measured. The experimental results show that the melting water conductivity of the ice layer and icicle decreases nonlinearly with an increase in the melting time under two conditions. The higher the cooling water conductivity is

the more obvious the crystallization effect will be. Owing to the heat effect of corona discharge

local arc and the leakage current

the melting water conductivity under energized condition will significantly be lower than that under non-energized condition.