TY - CHAP A1 - Wirth, Isabell A1 - Reumann, Andreas A1 - Zink, Markus H. A1 - Küchler, Andreas A1 - Langens, Achim A1 - Schnitzler, Tim T1 - Messung elektrischer und thermischer Transienten an Hochspannungsgleichstromdurchführungen T2 - Highvolt Kolloquium, Dresden, 2015 (Poster) Y1 - 2015 ER - TY - CHAP A1 - Küchler, Andreas A1 - Wirth, Isabell A1 - Reumann, Andreas A1 - Zink, Markus H. A1 - Schnitzler, Tim A1 - Langens, Achim A1 - Berger, Frank T1 - Steady-state and Transient Electrical Potential Distributions in HVDC Bushings Measured under Different Thermal Conditions T2 - 19th International Symposium on High Voltage Engineering N2 - High voltage DC (HVDC) applications become more and more important and the voltage level for energy transportation increases steadily. Hence the design of the DC insulation systems becomes more and more difficult. The difference between HVDC and HVAC insulation systems is that in HVAC the electrical field is distributed according to the permittivities of the materials. Permittivity is only weakly dependent on temperature, so there is no significant difference between the electrical field distribution at room temperature and operating temperature of the insulation system. In HVDC however the electrical field is distributed according to the conductivities of the insulation materials whereas the conductivity is strongly dependent on temperature. This can lead to completely different field distributions at varying temperatures. The investigations presented here show simulation results of HVDC bushing cores in comparison with measurements on those test objects. Simulations and measurements were performed both for temperature distributions and electric potentials of the grading layers in the bushing at DC voltage. For the first time, it was shown by experiment that the FEM simulation can reproduce real DC field distributions very well. It was also shown, that there is a strong influence of temperature gradients or temperature transients on transient and steady-state electrical potential distribution inside the insulation. Y1 - 2015 CY - Pilsen, Czech Repbulic ER - 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 - TY - CHAP A1 - Wirth, Isabell A1 - Reumann, Andreas A1 - Küchler, Andreas A1 - Schnitzler, Tim A1 - Langens, Achim A1 - Berger, Frank A1 - Zink, Markus H. T1 - Steady-state and Transient Electrical Potential Distribution in HVDC Bushings Measured under Different Thermal Conditions T2 - 19th International Symposium on High Voltage Engineering Y1 - 2015 CY - Pilsen, Czech Republic ER - TY - CHAP A1 - Küchler, Andreas A1 - Krieg, A. A1 - Lala, G. A1 - Schober, F. A1 - Wiener, J. A1 - Paulus, J. A1 - Zink, Markus H. A1 - Liebschner, M. T1 - FEM model for describing the dielectric behavior of oil-impregnated pressboard under DC stresses BT - SIP 2015 T2 - 33rd International Conference “Science in Practice” Y1 - 2015 UR - http://permalink.bibkatalog.de/BV042665355 CY - Schweinfurt ER - TY - CHAP A1 - Küchler, Andreas A1 - Schober, F. A1 - Liebschner, M. A1 - Berger, Frank A1 - Exner, W. A1 - Krause, Ch. A1 - Fritsche, R. A1 - Wimmer, R. T1 - Dielectric Behaviour of HVDC Insulating Materials, Polarization and Conduction Processes in Mineral Oil and in Pressboard Impregnated with Different Fluids T2 - 19th International Symposium on High Voltage Engineering Y1 - 2015 CY - Pilsen, Czech Repbulic ER - TY - CHAP A1 - Küchler, Andreas A1 - Harrer, S. A1 - Schober, F. A1 - Staab, T. A1 - Sextl, G. A1 - Exner, W. A1 - Krause, Ch. T1 - Influence of Water Content of Cellulosic Material on Dielectric Behaviour of HVDC insulation T2 - 19th International Symposium on High Voltage Engineering Y1 - 2015 CY - Pilsen, Czech Repbulic ER - TY - CHAP A1 - Küchler, Andreas A1 - Schober, F. A1 - Exner, W. A1 - Krause, Ch. A1 - Berger, Frank T1 - Influence of Board Density on the Conductivity of Oi-Impregnated Pressboard for HVDC Insulation Systems T2 - IEEE Electrical Insulation Conference Y1 - 2015 SP - 61 EP - 64 CY - Seattle, Washington, USA ER - TY - CHAP A1 - Küchler, Andreas A1 - Schober, F. A1 - Harrer, S. A1 - Krause, Ch. A1 - Berger, Frank T1 - Einfluss von Temperatur und Ligningehalt auf die elektrische Leitfähigkeit von Pressspan als HGÜ-Isolierwerkstoff T2 - 6. RCC-Fachtagung „Werkstoffe zur Anwendung in der el. Energietechnik unter den besonderen Anforderungen der HGÜ“ Y1 - 2015 SP - 268 EP - 273 CY - Berlin ER - TY - CHAP A1 - Küchler, Andreas T1 - Ausbildung und Steuerung elektrischer Felder bei Gleichspannungsbeanspruchung T2 - 6. RCC-Fachtagung „Werkstoffe zur Anwendung in der el. Energietechnik unter den besonderen Anforderungen der HGÜ“ Y1 - 2015 SP - 12 EP - 50 CY - Berlin ER -