Charge Transport Dynamics and Space Charge Accumulation in XLPE Composites with 2D Platelet Fillers for HVDC Cable Insulation

Abstract

Here, based on the dielectric response analysis, we report the charge transport dynamics as related to space charge accumulation for three model XLPE composites with 2D platelet silicate fillers. Dynamics of charge transport and the interplay between polarization and space charge are revealed by the equivalent circuit analysis with the Dissado-Hill dielectric response model. In addition to the quasi-DC process, a characteristic dielectric loss peak in the frequency range of 0.1 Hz to the power frequency is observed and attributed to the relaxation of charges trapped by filler-polymer interfaces. It is demonstrated that the physical nature of trapping and transport revealed by parameters extracted from the quasi-DC process and dielectric loss peak can be well correlated to the characteristics of space charge accumulations in the model XLPE composites containing distinctively different 2D platelet fillers.