Dielectric spectroscopy and absorption/resorption analysis of composite dielectric with MgO filler

Composite insulation systems are inseparable part of most electrical installations. Strongly inhomogeneous structure of these systems is the main problem which may lead to defect during operation life. Main aim of this paper is to introduce novel composite material designed for insulating system of high voltage equipment. This material is composed of epoxy resin matrix with dispersed magnesium oxide (MgO) nanoparticles and polyethylene naphthalate (PEN) film. The main emphasize is placed on behaviour of this material in AC electric field depending on frequency of testing voltage and ambient temperature and also on the behaviour in DC field. The characterization in AC field is based on broadband dielectric spectroscopy, on the other hand the behaviour in DC field is characterized by dielectric absorption. Parameters like real permittivity, loss factor and dielectric absorption and resorption are mentioned in this paper.