A Comparative Study on Electrical Tree Growth in Silicone Rubber Containing Nanoalumina and Halloysite Nanoclay

Recently, silicone rubber (SiR) is preferably used in high-voltage cable accessories because it offers a wide range of voltage and temperature applications and excellent electrical and mechanical properties. Furthermore, the SiR exhibits flexibility and inhibits oxidation. In this paper, the electrical tree behavior of SiR nanocomposites containing nanoalumina and halloysite nanoclay was investigated; moreover, the nanofiller concentrations were predetermined at 0 vol%, 1 vol%, 2 vol%, and 3 vol%. The electrical tree growth was observed at room temperature at 8 kVrms after tree inception voltage (TIV). The TIV and electrical tree growth in SiR nanocomposites were monitored using an online digital monitoring system, which consisted of a stereomicroscope and a digital camera. The experimental results indicated that the addition of 1 vol%-2 vol% nanoalumina in SiR composite significantly improved the TIV and electrical tree growth rate. However, the addition of 3 vol% nanoalumina in the SiR composite reduced the TIV and accelerated the electric tree growth rate. In the presence of halloysite nanoclay of approximately 3 vol%, the SiR composite showed improved TIV and electrical tree growth rate.