Effect of the Parameters of the Semiconductive Coating on the Anti-Icing Performance of the Insulators

Partial coating of insulators with semiconductive silicone rubber has proved to be a potential method for reducing ice accretion on insulators. The performance of the coated insulator strings is mainly determined by the insulator parameters, the coating resistance, and the coating area covering the insulator surface. This research is to investigate the effect of using semiconductive silicone rubber coating on the anti-icing performance of ceramic insulators, considering the coating resistance and the coating area. A series of icing tests was carried out in a climate room and the results obtained from tests on a single insulator unit were extended to short insulator strings. The experimental results showed that the magnitude of the appropriate coating resistance was below 0.3 MΩ in the freezing condition recommended, and that the suitable width of the band of the uncoated area was about 5 to 8 cm. Since the main heating power was consumed in the region of the uncoated band, the uncoated area should better be close to the edge of the top surface of the insulator, in which case the icicles could fall off more easily.