TY - CHAP A1 - Krieg, Andreas A1 - Lala, Gjergj A1 - Schober, Fabian A1 - Wiener, Johannes A1 - Paulus, Johannes A1 - Küchler, Andreas A1 - Zink, Markus H. A1 - Liebschner, Marcus T1 - FEM model for describing the dielectric behavior of oil-impregnated pressboard under DC stresses T2 - Papers of 33rd International Scientific Conference "Science in Practice" N2 - According to the worldwide growing demand for electric energy, it is necessary to construct safe and efficient power systems. HVDC (high voltage direct current) applications become more and more important due to larger distances for the energy transportation and the increasing demand for reactive power transportation. Appropriate insulation materials, i.e. mineral oil and pressboard, are widely used in HVDC components, mainly in power transformers though the knowledge about dielectric behavior of oil-impregnated pressboard under DC stresses in time domain is not sufficient. In this paper, a Finite Element Method (FEM) model is presented to describe the electrical conduction behavior of the material by separate consideration of mineral oil and pressboard. With this model the electric potential distribution under DC stress was simulated to analyze polarization and electrical conduction. The model parameters volume ratio as well as angle variations of FEM model are investigated and their influences on the current through the model are evaluated. Furthermore, geometrical and physical parameters are estimated and the results are compared to currents that are measured on oil-impregnated pressboard samples in time domain. KW - electrical conduction KW - FEM simultation KW - HVDC KW - polarization KW - oil-impregnated pressboard Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:863-opus-2609 SP - 62 EP - 66 ER -