Artificial icing and AC flashover tests on glass insulators with silicone acrylate resin hydrophobic coatings

Droplets on hydrophobic coating surfaces tend to roll off, which can reduce water volume for icing, help relieve the icing degree of insulators, and improve the electrical performance of iced insulators. Hydrophobic coating is considered as a potentially effective anti-icing method for insulators. Artificial icing and flashover tests for LXP-70 insulator strings coated with four types of silicone acrylate resin (SAR) hydrophobic coatings were conducted in an artificial climate chamber. Bare insulator strings were arranged as the control group. Ice morphology, ice density, growth of ice weight, and AC flashover voltage among different insulator strings were investigated under non-energized and energized conditions. The effects of different SAR coatings on icing performance mentioned above and AC flashover voltage were discussed. Test results indicate that the hydrophobic features of coatings significantly affected the morphology of ice layers of glass insulators with SAR coatings, that is, the stronger the hydrophobicity of the coatings was, the more granular the ice layer became. Ice density was lower on the insulator surface with SAR coatings than that on the insulator surface without coatings. SAR coatings with a contact angle (CA) more than 130° could significantly reduce the ice weight of glass insulators and increase their flashover voltages in the initial stage of the icing process. Coated insulator strings with a CA of 110° showed poorer anti-icing and flashover performances than the bare insulator string.