Pollution morphology characteristics on a superhydrophobic surface and its pollution flashover voltage in DC electric field

To solve the pollution problem of insulators on ultra‐high voltage DC transmission lines, superhydrophobic coatings were presented and their pollution deposit morphology and pollution flashover voltage in electric field were studied by an artificial pollution deposit system. The experimental results show that the pollution on the surface of superhydrophobic coating is distributed in clusters, which inhibits the chain distribution on the surface of silicone rubber and improves the pollution flashover voltage. Secondly, the competition mechanism of the pollution flashover on the superhydrophobic coating surface was found. This competition mechanism can lead to the failure of the insulation performance of the superhydrophobic coating in severely polluted environments. Finally, a pollution flashover model of superhydrophobic coating is proposed to explain the competition mechanism, which is affected by pollution and the discrete droplets. The conclusions of this study can provide an experimental and theoretical basis for the application of the superhydrophobic coating in the field of UHV DC external insulation.