Photoelectric Hybrid Coating For Anti-Icing Of Composite Insulators

The development of Chinese transmission lines has gradually matured,and the system has gradually improved,covering most of Chinese high-altitude,high-humidity,and heavy-covered areas.Therefore,the problem of snow and ice coating on the composite insulators of transmission lines has received more and more attention.The surface of the composite insulator is coated with photoelectric hybrid coating,which has the ability to absorb solar heat and generate leakage current,and is one of the ideas of composite insulators for preventing ice.The main work of this paper is as follows:?1?In the rain-covered environment?environment temperature:-6⁰°C,wind speed:2¹5m/s,median diameter of water droplets:20¹00?m?,the heat transfer balance equation of composite insulators was analyzed and established.The critical anti-icing power density and leakage current in this environment were calculated.According to the environmental conditions,the main factors affecting the critical ice protection power density and critical current were summarized.The threshold anti-icing power density of composite insulators is between 23.7 W/m² and 635.6 W/m²,and the threshold anti-icing current is between 0.15 mA and 4.28 mA.It is greatly affected by the ambient temperature and wind speed.?2?The photothermal power and electric heating power required for anti-icing of composite insulators are analyzed and derived,and the range of critical solar power density for anti-icing and volume resistivity of photoelectric hybrid coatings is given.In the rain-covered environment,the volume resistivity of the photoelectric hybrid coating that meets the leakage current of less than 1 mA is between 4.82×10⁶?·m and 7.76×10⁷?·m.The intensity of solar required for anti-ice is between 144 W/m² and 1899 W/m².It is difficult to achieve threshold anti-icing power under icing weather,and it is difficult to achieve the effect of reducing ice coating.?3?This paper presents a preparation method of photoelectric hybrid coating:using that coprecipitation method to prepare the FeMnCuO₄ complex metal oxide powder as light-absorbing pigment,using graphite as conductive paint,using room temperature vulcanized silicone rubber as base material and KH550 was as coupling agent,to make photoelectric hybrid coating.The parameters such as hydrophobicity,self-cleaning property and volume resistivity of different photoelectric hybrid coatings were measured.The results shows that when FeMnCuO₄ has a mass fraction of 5wt%to 10wt%and a graphite mass fraction of 13wt%to 18wt%,the parameters such as hydrophobicity and self-cleaning property of the photoelectric hybrid coating did not change much compared with pure RTV.And the volume resistivity of the photoelectric hybrid coating is maintained between 10⁶?·m and 10⁸?·m,the leakage current is maintained at about 1mA,and it has a certain light absorption performance,the coating has conditions for heat generation by leakage current and absorption of sunlight to prevent heat from building.?4?The artificial icing tests was carried out on composite photoelectric composite insulator composed of FeMnCuO₄ with mass fraction of 5wt%and graphite with mass fraction of 13wt%,15wt%and 18wt%have anti-icing performance.The electric heating power plays a major role,and the photothermal power has little effect.Among them,the composite insulator with FeMnCuO₄ mass fraction of 5wt%and graphite mass fraction of 13wt%has surface leakage current less than 1mA in winter,and has a certain effect of reducing ice coating.However,the long-term leakage current of 1 mA on the surface of the composite insulator will cause serious safety hazard to the system.Therefore,the application of the photoelectric hybrid coating to the composite insulator anti-icing field should be taken with caution.