Graphical abstract

Polymer nanocomposites materials have recently emerged as a dielectric and for electrical insulation. Polyethylene has long been used as extruded cable and HV insulation. Currently, this material has received significant attention because of its ability to enhance electrical insulation properties by addition of nano-filler. Polarization and Depolarization Current (PDC) measurement is an efficient and effective diagnostic technique based on time domain measurement for evaluating and condition monitoring of polymer nanocomopsite for HV insulation. Electrical conduction for polymer nanocomposites has been used widely as a tool to monitor the dielectric behaviour. This paper focuses on application of Polarization and Depolarization Current (PDC) testing method to evaluate and determine the performance of LLDPE nanocomposite for high voltage insulating material. The experiment was conducted to find PDC pattern of the material when added with nano-filler (silicon oxide) as well as to find its conductivity values at different percentage of nano- filler. PDC values and DC conductivity exhibits significant reduction with addition of nano-filler at different %wt of concentration. This was due to the decrease of initiation probability of short circuit treeing in the insulation. The PDC result shows that addition with certain percentage of nano-filler into the LLDPE based material could improve HV insulation propertie