Study on surface conductivity distribution of pollution layer during the propagation of local arc on the wet polluted insulation surface

The surface conductivity of the pollution layer plays a pivotal role in the investigation of flashover voltage and the propagating mechanism of the local arc. In order to study the characteristics of the pollution layer, an experimental system is designed in this paper. Ferric chloride is employed as the color indicator for demonstrating the dry state distribution of the pollution layer. Thus, the surface conductivity is calculated by analyzing the red–green–blue value of the pollution layer. In addition, a numerical model for calculating the heat transfer on the surface of the pollution layer is also established. It has been revealed that the dry state distribution of the pollution layer is affected by the leakage current and the speed of the local arc. Moreover, the relationship between the surface conductivity of the pollution layer and the thickness of the surface water film is obtained. The comparative analysis shows that the calculated results are in good agreement with the experimental data.