Studying Dielectric Losses of Serially Combined Silicone Rubber and Epoxy Resin

Abstract

High voltage outdoor insulation systems are conventionally ceramics and glass with several advantages, such as proven in the field, excellent dielectric properties, durability, and long life. However, they are heavy, attract vandals and break easily, and they can lose their dielectric properties easily when subjected to high voltage transients, arcing, and surges. To curb this, polymer insulators are used because they have excellent dielectric properties, such as those of ceramics and glass, with the added advantages that they do not break easily and recover their lost dielectric properties after any electrical transients. Therefore, this paper investigates the dielectric properties of polymeric materials – silicone rubber (SR) and epoxy resin (ER). Some SR samples were manufactured in the laboratory, and others were obtained from the industrial manufacturer. All the ER samples were manufactured in the laboratory. The dielectric measurements were performed with the Insulation Diagnostics System. Within the measured frequency ranges, the dielectric losses of SR manufactured industrially differ from the laboratory-manufactured specimens. This is due to filler materials in the industrially manufactured samples. For the case of serially connecting the SR and ER, there was a higher influence of dielectric loss of SR than the ER, with some remarkable dielectric losses at some frequencies.