This paper reports on an investigation into the space charge formation and decay at different material interfaces. In particular, the influence of the interface between electrode and polymer or polymer and polymer on the space charge dynamics has been studied. Planar samples were subjected to high dc electric stresses for extended periods of time and space charge measurements taken using the pulsed ( ) electroacoustic PEA technique. It has been found that the types of interface between electrode and polymer play a significant role in determining the charge distribution in the insulation and that the interface between polymer and polymer acts as a potential barrier to electrons while allowing positive charge carriers through easily.Index Terms -LDPE insulation, insulation interface, space charge dynamics, PEA technique, effect of electrode materials, charge formation, charge decay, potential barrier.
Fillers are widely used in insulation systems to achieve specific electrical, mechanical and thermal properties. Recently, polymer nanocomposites have attracted significant attention as a means of improving their performance and widening their utility. To better use the nanocomposites, a thorough understanding of interaction between nanoparticles and their matrix is important. The interaction can be studied by various methods. In the present study we focus our attention on space charge dynamics of linear low density polyethylene (LLDPE) loaded with nanometric size aluminium oxide (alumina) under dc electric fields. To obtain a good dispersion of nano fillers in LLDPE, a Brabender mixer has been utilised. Four types of LLDPE nanocomposite films were prepared with concentrations of alumina of 0, 1, 5 and 10 wt% for space charge measurements. They were electrically stressed at three electric field levels of 10, 50 and 100 kV/mm and space charge dynamics during stressing period and decay after the removal of the applied electric field were observed. The results show that space charge dynamics in nanocomposites are dependent on both content of filler and the applied electric field. Generally, the amount of space charge in the sample with 1% of alumina is less while there is a significant change in characteristics in the sample loaded with 5% alumina or more. In particular, the electrical performance in the sample with 10% alumina deteriorates, indicating there is an optimal load of alumina.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.