Performance Enhancement of Polymeric Outdoor Insulators with Superhydrophobic Coating

Polymeric outdoor insulators are an essential component in transmission and distribution power systems. These insulators encounter complex stress (electrical, environmental, and chemical) during operation, which could lead to many consequences and eventually complete breakdown of the insulator, such as hydrophobicity loss, surface pollution, surface charge accumulation, and premature aging and degradation. The study proposes a simple, low-cost, and stable superhydrophobic coating based on polydimethylsiloxane PDMS and silica (SiO2) for polymeric outdoor insulators to solve these issues. The superhydrophobic surface shows a very high static contact angle of 159.2°, superior self-cleaning properties (sliding angle=6.9°), and high thermal stability. We investigated the performance of the superhydrophobic 15 kV polymeric insulator under different operating (AC and DC), environmental (dry, fog, and rain), and chemical (clean and salt) conditions. The superhydrophobic insulator shows superior performance compared with the ordinary insulator by improving the surface resistance, minimizing leakage current, preventing the initiation of surface discharge, and increasing the flashover voltage. The superhydrophobic coating enhances the performance of HV SiR insulators and ensure reliable and stable operation under various adverse operating conditions (wet and polluted conditions).