Review on Thermal and Electrical Properties for Condition Assessment of Epoxy Nano- Composites by Advanced Techniques

Epoxy nano-composites along with inorganic nanoparticles as filler, can exhibit excellent properties, such as ameliorated mechanical strength, improved thermal conductivity, enhanced dielectric strength, and reduced dielectric dissipation factors. Therefore, epoxy-based insulation is employed in power transformers, motors, generators, converter transformers, gas-insulated switchgear, and gas-insulated transmission lines. This article aims to review the dielectric and thermal properties of epoxy nano-composites with incorporated inorganic nano-fillers. Proper dispersion of nanoparticles inside the polymer matrix can effectively improve the dielectric strength and thermal properties of epoxy insulation. Excessive dispersion of nano-fillers can cause agglomeration and defects between the fillers and matrix, resulting in insulation problems such as higher dielectric loss and reduced dielectric strength. It is considered that the dispersion of nanoparticles in proper ratio can effectively improve the dielectric properties of epoxy insulation. Therefore, an augmented perception of the nanoparticle–epoxy interfaces in nano-composites can enable a pragmatic analysis of the desired properties, opening new arrays for application.