Reduction of Flashover in Ceramic Insulator with Nanocomposites

High Voltage (HV) insulator plays an important role in electrical power systems. In addition to the mechanical support of the conductors, their electrical role is to isolate the metal structure of the tower from the conductor. Ceramic insulators suffer from many pollutants from different sources, such as (lust, saline and sand storms. Contaminated high voltage ceramic insulators in presence of humidity due to fog, rain, and severe temperature changes certainly lead to leakage current, dry band arcing, and ultimately may cause flash over, which results in power outages. Depending on the pollution severity of the site, outdoor insulators need to have sufficient leakage length to ensure minimized dry band formation and surface arcing. Ceramic insulators suffer from hydrophilic surface property, allowing high surface leakage current to flow on the wet surface which causes flashover due to contamination. Utilities have used Room Temperature Vulcanization (RTV) coatings and greasing to improve the surface properties of the insulators. Although effective, these remedies are labor intensive and expensive. In this work, Liquid Silicone Rubber with 1% of Zirconia nano powder was used for coating on the surface of the porcelain. The flash over, pollution performance and comparative tracking index tests were conducted on the above sample as per IEC standards 60243, 60507, 61109, 60112 and 815. Silicon Rubber with Nano composite coated porcelain showed good flashover characteristics.