Investigation of Ageing Characteristics of Silicone Rubber in Mineral Oil

摘要

The life expectancy of a high voltage equipment is governed by the functioning of its insulation. The operational lifetime of an oil filled electrical equipment increases when its insulation system exhibits good ageing behaviour. In this contribution, the influence of the ageing duration on the dielectric behaviour of silicone rubber in mineral oil is investigated. The behaviour is compared with the ageing characteristics of pressboard in mineral oil and also with mineral oil without any solid insulation samples. Three types of silicone rubbers are considered in this study, namely, conductive silicone, insulative silicone and samples containing both conductive and insulative silicone. The samples were aged at 130 °C for durations of 360, 720 and 1080 h. After the completion of each ageing duration, aged samples were measured for their dielectric properties. The mineral oil samples were measured for their moisture content, dissolved gases and breakdown voltage. Whereas, the solid insulation samples were investigated for their moisture content. The obtained results are analysed and the influence of the ageing duration on dielectric behaviour is investigated.