Influence of electric field on the ice-coating process of insulators with a different dielectric surface

Studying the influence of electric field on the icing process of insulators with various dielectric surfaces is of great importance to the design of external insulation. This study established a finite element model to simulate the distribution of electric field around various insulator strings. Energised and non-energised icing tests were conducted to obtain the influence rules of electric field on the insulator icing process. The results of water droplets freeze experiment provided microscopic explanation of icing tests. Research results indicate that electric field and surface dielectrics have influence on the appearance, density and mass of ice on insulators. In microcosmic view, water droplets on super-hydrophobic surface correspond to longer freezing time and smaller average diameters, which leads to the better anti-icing character of super-hydrophobic insulator. Different types of ice branches appear in the water droplets freezing process on various dielectric surfaces. Owing to the polarisation effect, electric field can inhibit the formation and growth of ice branch, which contributes to different anti-icing characters of various dielectric surfaces in electric field. The effect of dielectric surface on insulator icing process mainly act at the initial period, surface coatings of insulators are not suggested to be applied in heavily icing area.