Durable Hydrophobic Coatings for High Voltage Silicone Rubber Insulators

J.C. Kelly, A. Goff, B. Koene
Luna Innovations, Inc.,
United States

Keywords: hydrophobic coating, water shedding, silicone rubber, high voltage insulators, arc discharge

Summary:

Luna Innovations is developing a durable and hydrophobic sol-gel coating for high voltage silicon rubber (SiR) insulating materials. The coating technology effectively sheds water and other contaminants, reduces damaging corona discharge events under high voltage electric fields, and enhances the safety and long-term operation of SiR insulators. The easy-to-apply coating is designed to reduce degradation of SiR bushing components by i) providing excellent water- and contaminant-shedding capabilities in the presence of high power electric fields, and ii) imparting a durable and dense layer to protect components against harsh environmental service conditions. This hydrophobic sol-gel coating is inherently non-hazardous and is being designed for both original equipment manufacturing (OEM) application to new SiR bushing components and for field application to existing components via brush or spray application. Luna has demonstrated the hydrophobicity of the coating as compared to bare SiR surfaces and its superior environmental durability over a wide range of conditions. The sol-gel has proven to be extremely effective at providing a hydrophobic surface while immersed in high voltage electric fields and Luna is currently developing the coating for full-scale bushing component materials.