The role of polymer composite with high voltage applications

Abstract:

The high-voltage insulation applications of low-density polyethylene (LDPE) and its nanocomposites have become increasingly important due to their superior dielectric and thermal performance. This paper reviews recent progress in LDPE-based polymer nanocomposites with respect to power engineering aspects, namely permittivity, breakdown strength, thermal conductivity, and aging behaviour. We then proceed to elaborate on the mechanisms for dispersing nanoscale fillers to maximize electric-field utilization, reduce space charge, and improve thermal transport, with only minimal loss of mechanical toughness—by comparing existing mixing rules with experimental observations of interfacial polarization. This work combines nonlinear conductivity and field-enhanced conduction by considering filler-induced modifications to trap states. The increase in breakdown strength (15-40% of the virgin value) is attributed to energy losses at filler sites, charge trapping, and crack-arrest effects. Thermal management and percolation-driven improvements in conductivity at filler loadings>∼15-20% are also covered. Finally, the study addressed long-term thermal stability and the dual role of fillers as catalysts and stabilisers in polymer oxidation. The dielectric and thermal properties of LDPE containing various nanofillers. Their major applied areas, including environmentally friendly HV cables, transformers, and rotating machines, are reviewed, together with various challenges such as filler dispersion and economic upscaling. Finally, emerging strategies based on hybrid fillers, graphene-based filler methods, and novel interface engineering are proposed toward next-generation thermal insulation. This study will help orient research on LDPE nanocomposites for ultra-high-voltage power systems.