Publication

Abstract : Cross-linked Polyethylene (XLPE) cables are widely used for medium voltage underground cables these days. However void and impurity defects have been a major reason for the failure of cable insulations as these defects induces internal discharges and cause a significant change in the dielectric properties of the insulation. For the same reason, polymer nano composite materials have emerged out as a superior insulation material as they have considerable improvement in terms of reduction of mechanical and electrical erosion, electrical breakdown endurance behavior etc. In this paper, the AC characteristics of XLPE-nanocomposites with insulating nanofiller like layered silicate are investigated at various filler concentrations by weight. Using melt mixing method, XLPE nanocomposite samples with uniform dispersion of fillers were prepared and their ac dielectric strengths were studied. In addition, electric field stress in XLPE- nanocomposites is also analyzed using COMSOL Multi-Physics simulation software to have a better understanding of the breakdown mechanism of the insulation. It was observed from the experimental results that the dielectric strength gradually increased with filler concentration up to 5 weight percent and then decreased.