Study on the self-cleaning phenomenon and anti-pollution flashover performance of micro-nanostructure superhydrophobic coating surface under a high humidity environment

Using micro-nanostructure superhydrophobic coating with the unique self-cleaning phenomenon is a feasible method to further reduce the frequency of insulator pollution flashover. However, the research on the antipollution flashover performance of superhydrophobic coating is still insufficient. This paper analyzes the various types of forces on the polluted particles accumulated on the superhydrophobic coating surface, and calculates that the vertical force or the horizontal force on the nano-scale and micro-scale particles is positive when they are in contact with most types of droplets. After being fully wetted, these particles are easily absorbed or pulled by the droplets and leave the coating surface. So it is necessary to establish a new DC pollution flashover mechanism model of superhydrophobic coatings surface from the electric field perspective. Based on this model, the relationship between the pollution flashover voltage and the dry flashover voltage is clarified in the state of extremely small leakage current. Furthermore, the anti-pollution flashover performance experiment was carried out on superhydrophobic coating, RTV coating, and uncoated surface to test the leakage current under different conditions. The experimental results show that at any pollution degree, the leakage current of superhydrophobic coating surface always remains about 16.3 mu A after being completely wetted.