Effect of Environmental Desert Conditions on the Performance of Hydrophobic Polymer Insulators Surfaces

Polymeric insulators are widely used in newly constructed systems and to replace porcelain and glass insulators in existing power lines due to its improved performance. This paper presents an experimental work, which was carried to evaluate the flashover voltage (kV) of Silicone rubber / Ethylene propylene diene monoemer blends of outdoor insulators. Effect of environmental parameters at desert conditions on the electrical performance of polymer materials has been studied. Each test was repeated five times on each sample under the same conditions to check the accuracy of the results. Results showed that SiR material without any additions gives the best electrical performance with respect to blends of SiR / EPDM and EPDM only. Increasing conductivity, number of droplets and increasing droplet volume cause a reduction of the flashover voltage. Also measurements show that the flashover voltage 13 kV for blend (50% SiR/ 50% EPDM) of one water droplet with volume 0.05ml and water conductivity 5000 μS/cm. Surface roughness (Rmax. μm) of different blends has been estimated after exposure to artificial sand storm. The flashover voltage reaches to 8.51 kV at surface roughness 9.62 Rmax. μm for blend of three water droplets with 0.15 ml volume droplet and 20000 μS/cm . Keywords— Flashover voltage, Polymer blend, Surface roughness, Ultraviolet (UV) radiation, Hydrophobicity.