Performance Evaluation of Developed Superhydrophobic Coating for Polymeric Outdoor Insulators

Polymeric outdoor insulators are being widely employed in power transmission systems because of their promising features, especially lightweight and better contamination performance; however, their long-term performance under extreme environmental conditions (heavy pollution and icing conditions) is still challenging and governs the reliability of power transmission systems. In addition, many fracture incidents of polymeric insulators have been reported recently in several countries, which may result in a complete shutdown of the transmission line. This work aimed to investigate the influence of superhydrophobic coating on the performance of polymeric outdoor insulators. A simple, low-cost superhydrophobic coating with excellent hydrophobic properties, self-cleaning characteristics, and durability was prepared based on hydrophobic nanosilica and polydimethylsiloxane (PDMS) polymer. The prepared nanoparticle suspension was sprayed on high-temperature vulcanized (HTV) silicone rubber (HTV SiR) slabs and a full-scale 11 kV composite outdoor insulator. The surface morphology, elemental composition, and the change in molecular bonding of coated samples were characterized using the scanning electron microscope (SEM), energy-dispersive X-ray spectrum (EDS), and Fourier-transform infrared spectroscopy (FTIR), respectively; moreover, coated HTV SiR sheets show superior dielectric characteristics. Simulation results of coated samples show improved electrical field distribution under wet conditions. Finally, during experimental investigations, the coated insulator presented outstanding performance, especially under wet conditions where flashover voltage increased by more than 30%, and the leakage current decreased by more than 44%. These promising results could help in improving the long-term performance of composite insulators, especially in wet and polluted areas.