Enhancement of protective layer coated bushing under artificial coastal pollution conditions

Insulation performance of an electrical power system is greatly affected by the various pollution components. The level of pollution severity on the surface of insulation also determines the rate of breakdown voltage. Here, high voltage bushing is exposed to the artificial pollution conditions such as coastal pollution. This paper analyses the performance of normal bushing and silicone grease coated bushing which are polluted by the mixture NaCl and kaolin contaminants. The breakdown voltage test is carried out under both dry and wet conditions. Finally pollution breakdown voltage of normal bushing is compared with silicone grease coated bushing. The report shows that, the silicone grease coated bushing is an excellent solution to solve very severe contamination flashovers. This is due to the hydrophobic coating over the bushing.