The development of silicone rubber composite insulators in power system

Power sector is one of the important infrastructures, which gets affected due to disasters leading to disruption in generation, transmission and distribution of electric power. One of the reasons is the deposition of pollutants on the insulators which start conducting during foggy weather conditions resulting in flashover and interruption of power. Amongst the non-ceramic insulators, silicone rubber insulator is better equipped to deal with flashover problems due to its unique hydrophobicity property. The hydrophobicity property of silicone prevents the formation of water forming on surface of insulator. Silicone rubber insulators have many advantages over the ceramic and glass insulators such as good performance in contaminated environment, easy handling, maintenance free, light weight, high strength to weight ratio, high impact resistance etc. Because of these properties it is gaining popularity worldwide and replacing the conventional ceramic and glass insulators in power transmission all over the world. The present paper deals with designing aspects of the silicone rubber composite long rod insulator and testing the same by performing ´Tracking and Erosion test´. As the surface degradation in outdoor applications of either tracking or erosion occurs because of association with arcing over dry bands which develops during or immediately after precipitation. The surface damage, erosion or carbonization results from the heat of the arc and this damage accumulates until the surface between the electrodes can no longer sustain the applied voltage. Tracking and erosion test is a simulated environment testing facility developed at ´ERDA´ which simultaneously tests ultra violet light, rain cycle, voltage, heating and salt-fog environment. This is based on IEC 61109 (1992). The performance of the insulator is compared with the conventional porcelain insulator. The results obtained are encouraging.