Influence of Algae Growth on the Electrical Performance of RTV Coated Post Insulators

Algae are found grow on the surface of room temperature vulcanized (RTV) silicone rubber coated insulators installed in warm and humid region such as Sichuan, which brings potential operating risk to power transmission and transformation equipment. In this research, two different types of 110kV RTV coated post insulators with algae growth were obtained from Sichuan. Firstly, the algae coverage rate of upper and lower surfaces of top, middle and bottom shed of insulators were calculated through the image processing method respectively. Then, the wet impulse puncture voltage and fog flashover voltage were tested on the algae-grow insulators as well as clean ones. Lastly, the equivalent salt deposit density (ESDD) and no soluble deposit density (NSDD) of insulators were measured. The results show that the algae on the lower surface of insulators are significantly less than the upper surface. Algae have no effect on impulse puncture voltage of insulators. However, the algae decrease the flashover voltage of insulators under the condition of steam fog by 25.2%~44.0% compared to the clean ones.