Selection of semiconductive coatings at different ambient temperatures

Anti- and de-icing techniques for the power systems have been attractive topics in recent years. Semiconductive silicone rubber coatings have been considered and applied in a few regions of China. This paper focuses on the problem of selecting semiconductive coatings under different ambient temperatures. In order to select the semiconductive coatings, the volume resistivity of the coatings doped with various carbon black concentrations was first tested. Then a series of icing/anti-icing tests on bottom-coated insulator strings were carried out in a climate room, where their antiicing performance was studied in terms of icing appearance, ice accretion weight, leakage current and surface temperature. The results show that when the ambient temperature is -2, -4 and -6 °C, the coating resistivities required to prevent ice accretion on the insulator strings tested are presented in this paper.