@incollection{KuechlerZinkVolletal., author = {K{\"u}chler, Andreas and Zink, M. and Voll, S. and Berger, Frank and Klipfel, V.}, title = {Der Einfluss von Temperatur und Streukapazit{\"a}t auf diagnostische Kapazit{\"a}ts- und Verlustfaktormessungen von 400 kV-Hochspannungstransformatordurchf{\"u}hrungen}, series = {ETG-Fachbericht 134}, booktitle = {ETG-Fachbericht 134}, publisher = {VDE}, address = {Fulda}, language = {de} } @inproceedings{KuechlerZinkBergeretal., author = {K{\"u}chler, Andreas and Zink, M. and Berger, Frank and Klipfel, V.}, title = {Electrical Simulation as a Tool for Ageing-condition Assessment of Generator Transformer Bushings}, series = {2012 IEEE International Conference on Condition Monitoring and Diagnosis CMD}, booktitle = {2012 IEEE International Conference on Condition Monitoring and Diagnosis CMD}, address = {Bali, Indonesia}, pages = {23 -- 27}, language = {en} } @inproceedings{KuechlerSchoberKriegetal., author = {K{\"u}chler, Andreas and Schober, F. and Krieg, A. and Liebschner, M. and Berger, Frank}, title = {Parameter influences on HVDC transformer insulation and its link to conduction processes}, series = {32nd International Conference "Science in Practice"}, booktitle = {32nd International Conference "Science in Practice"}, address = {Osijek, Croatia}, language = {en} } @inproceedings{SturmWirthPaulusetal., author = {Sturm, Sebastian and Wirth, Isabell and Paulus, Johannes and Zink, Markus H. and K{\"u}chler, Andreas and Berger, Frank}, title = {Transient dielectric simulation in time domain with FEM in comparison with circuit models}, series = {XIX International Symposium on Theoretical Electrical Engineering, Ilmenau, 2017}, booktitle = {XIX International Symposium on Theoretical Electrical Engineering, Ilmenau, 2017}, language = {en} } @inproceedings{ZinkBergerKlipfeletal., author = {Zink, Markus H. and Berger, Frank and Klipfel, V. and K{\"u}chler, Andreas}, title = {Ageing Condition Assessment of 400 kV OIP Generator Transformer Bushings}, series = {17th ISH International Symposium on High Voltage Engineering}, booktitle = {17th ISH International Symposium on High Voltage Engineering}, address = {Hannover}, language = {en} } @inproceedings{KuechlerSchoberExneretal., author = {K{\"u}chler, Andreas and Schober, F. and Exner, W. and Krause, Ch. and Liebschner, M. and Berger, Frank}, title = {Interaction of Pressboard with Impregnating Fluids in HVDC Insulation Systems}, series = {IEEE Electrical Insulation Conference}, booktitle = {IEEE Electrical Insulation Conference}, address = {Philadelphia, Pennsylvania, USA}, pages = {276 -- 280}, language = {en} } @incollection{KuechlerWirthReumannetal., author = {K{\"u}chler, Andreas and Wirth, Isabell and Reumann, Andreas and Zink, Markus H. and Schnitzler, Tim and Langens, Achim and Berger, Frank}, title = {Steady-state and Transient Electrical Potential Distributions in HVDC Bushings Measured under Different Thermal Conditions}, series = {19th International Symposium on High Voltage Engineering}, booktitle = {19th International Symposium on High Voltage Engineering}, address = {Pilsen, Czech Repbulic}, abstract = {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.}, language = {en} } @incollection{KuechlerSchoberLiebschneretal., author = {K{\"u}chler, Andreas and Schober, F. and Liebschner, M. and Berger, Frank and Exner, W. and Krause, Ch. and Fritsche, R. and Wimmer, R.}, title = {Dielectric Behaviour of HVDC Insulating Materials, Polarization and Conduction Processes in Mineral Oil and in Pressboard Impregnated with Different Fluids}, series = {19th International Symposium on High Voltage Engineering}, booktitle = {19th International Symposium on High Voltage Engineering}, address = {Pilsen, Czech Repbulic}, language = {en} } @inproceedings{KuechlerSchoberBergeretal., author = {K{\"u}chler, Andreas and Schober, F. and Berger, Frank and Exner, W. and Krause, Ch.}, title = {Pressboard in HVDC Transformer Insulation}, series = {SIP2013 International Conference Science in Practice}, booktitle = {SIP2013 International Conference Science in Practice}, address = {Bremen}, pages = {27 -- 29}, language = {en} } @incollection{KuechlerLiebschnerKrauseetal., author = {K{\"u}chler, Andreas and Liebschner, M. and Krause, Ch. and Heinrich, B. and Leu, C. and Berger, Frank}, title = {Oil Ducts and Solid Insulation in Barrier Systems at HVDC Stresses}, series = {54th IWK Internationales Wissenschaftliches Kolloquium Ilmenau}, booktitle = {54th IWK Internationales Wissenschaftliches Kolloquium Ilmenau}, address = {Ilmenau}, language = {en} } @incollection{KuechlerZinkBergeretal., author = {K{\"u}chler, Andreas and Zink, M. and Berger, Frank and Klipfel, V.}, title = {Ageing Condition Assessment of 400 kV OIP Generator Transformer Bushings}, series = {17th ISH International Symposium on High Voltage Engineering}, booktitle = {17th ISH International Symposium on High Voltage Engineering}, address = {Hannover}, language = {en} } @incollection{KuechlerLiebschnerZerretal., author = {K{\"u}chler, Andreas and Liebschner, M. and Zerr, E. and Heinrich, B. and Krause, Ch. and Schmitt, Ph. and Berger, Frank}, title = {Interaktion von {\"O}lspalten und fester Isolation in HG{\"U}-Barrieren-systemen}, series = {ETG-Fachbericht 125}, booktitle = {ETG-Fachbericht 125}, publisher = {VDE}, address = {K{\"o}ln}, language = {de} }