Impact of Nanoparticle Structure on Resistance to Partial Discharge and Electrical Treeing in Epoxy Nanocomposite

The failure of polymer dielectric insulation in power apparatus is often caused by partial discharge like electrical tree growth due to the presence of cavity either inside or on the surface of the insulation. To enhance the resistance to partial discharge (PD) and improve its lifespan, epoxy with nanofillers based nanocomposites are being prepared and evaluated for various properties such as thermal and aging behaviours. The aim of this work is to understand the influence of spherical and layered structure of nanoparticles with suitable weight percentage (wt%) added to the epoxy to enhance its resistance to PD. Epoxy is chosen as the base material, and nano sized spherical titanium dioxide (TiO
2
) and layered silicate (Nanoclay) are used as nano fillers. Unfilled epoxy and epoxy with 2.5wt% and 5wt% of TiO
2
and nanoclay nanocomposites are used to investigate the effect of nanofiller inherent permittivity and its concentration on partial discharge resistance. The study also analyzes the structural changes at the interface, which is evident from the measured value of Glass transition temperature (Tg) of the nanocomposites and the PD patterns and the electrical tree penetration at a constant ac voltage of 30kV, 50Hz. The results shows that the structure of nanoparticles greatly influenced the resistance to partial discharge and electrical tree path in epoxy nanocomposite. A simulation model representation is analysed to understand the electrical treeing behaviour in nanocomposites.