| Overhead transmission lines are easily influenced by snow and ice weather, the mechanical and electrical damage caused by icing is the main hazards for transmission lines. Therefore, it is of great academic significance and engineering value to develop new technology for anti-icing of transmission lines. In this paper, preparation of wear resistant super-hydrophobic coating was studied, and the wear resistance, hydrophobicity and dielectric properties of the super hydrophobic coating were tested and analyzed. The electrification phenomenon of self-bouncing droplets and anti-icing characteristics on the surface of super hydrophobic coating were studied by low temperature simulation experiment. The main contents of the paper are as follows:(1) The structure and composition of superhydrophobic coating formed on the surface of copper electrodes and silicone rubbers after arc discharge are analyzed and the micro/nano-fillers are prepared from silicone rubber waste treated with atmospheric arc. Basic requirements for the micro-structure and chemical composition of the durable super-hydrophobic coating were analyzed, and a simple method for the preparation of wear-resistant super-hydrophobic coating on the large, curved surface was proposed, which is moving spraying of modified micro/nano-particles. Wear-resistant super-hydrophobic coating with micro/nano-structures was successfully prepared. Surface microstructure, chemical composition, hydrophobicity and adhesion of the wear resistant super-hydrophobic coating were tested.(2) A method was proposed to prepare hybrid superhydrophobic/semicondutive coating. The surface temperature of the coating is improved by using the electric heating effect. And the superhydrophobicity, wear resistance and adhesion of the coating are tested. Results show that the coating remained superhydrophobicity, good wear resistance and high adhesion after wear test; Furthermore the electric heating performance, surface temperature distribution of coating, and the influence of conductive fillers on surface temperature rise are studied.(3) The dielectric constant, dielectric loss, volume/surface resistivity and volume resistivity/temperature relationship of the semiconducting/superhydrophobic coatings with carbon and polyaniline are studied. The reason why semiconducting/superhydrophobic coating with carbon has negative dielectric constant under power frequency is analyzed. The low flashover voltage of the coating is explained by using the negative dielectric constant. And the flashover voltage and leakage current under power frequency and different filler contents are tested. Results showed that semiconducting/superhydrophobic coating with polyaniline can increase the resistance, decrease the leakage current, thus can inhibit the thermal runaway of the coating. Furthermore, the secondary electron emission image of semiconducting/superhydrophobic coating with polyaniline is analyzed. The coating is verified to restrain the leakage current from the microscopic scale.(4) The microscopic frosting process of semiconducting super-hydrophobic coating under low temperature was tested. The self-jumping phenomenon of micro-droplets, charge amount and type of the droplets, and electrokinetic behavior of charged droplets on the super-hydrophobic surface under low temperature were studied and analyzed. It is proved that the coating is able to delay the freezing process. The melting process of the frost on surface of the coating was further studied. Results show that coating can delay the icing on the surface. With the help of droplets jumping and electrokinetic effects, the condensation on the surface can be delayed. At the same time, the super-hydrophobic coating with polyaniline can remove ice under the electric heating effect efficiently.(5) The anti-ice performance of the coating is studied in the artificial climate chamber.The ice morphology, ice weight, flashover voltage and leakage current of insulators with coating under power frequency and ice accretion are tested. Results show that the semiconducting superhydrophobic coating with polyaniline has good anti-ice performance, it can delay icing on insulator strings, effectively reduce the ice weight on insulators. Under the same icing condition, semiconducting superhydrophobic coating with polyaniline can significantly increase the flashover voltage of glass insulators under ice accreation.The results of the above study indicate that the wear resistant and stable super-hydrophobic semiconducting coating can be prepared by moving spraying method. The coating has good electrical properties, and good anti-ice effect under icing environment. |
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