Pollution can increase leakage current along insulator surfaces, leading to flashovers, line trips and possible outages. There are different options to cope with this: One is increasing leakage distance and selecting the most suitable insulator profile. A second consists of applying silicone rubber insulators which offer a hydrophobic surface but must be properly specified and designed to avoid risk of permanent damage from sustained exposure to corona. A third alternative is applying a silicone coating over glass or porcelain insulators.
Recently, there has also been research on application of naturally hydrophobic and even ‘super hydrophobic’ surface treatments in order to achieve the water repellency of silicone but without the silicone. This edited contribution to INMR by J.M. George, Scientific Director at Sediver, presents findings from recent investigations into the pollution performance of such treatments.
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