@incollection{KuechlerReumannZinketal., author = {K{\"u}chler, Andreas and Reumann, Andreas and Zink, M. and Voll, S. and Berger, Frank and Langens, Achim and Titze, J.}, title = {Der Einfluss von Temperatur, Feldst{\"a}rke und Atmosph{\"a}re auf die Alterung von OIP Hochspannungstransformatordurchf{\"u}hrungen}, series = {ETG-Fachbericht 134}, booktitle = {ETG-Fachbericht 134}, publisher = {VDE}, address = {Fulda}, language = {de} } @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} } @incollection{KuechlerLiebschnerKrauseetal., author = {K{\"u}chler, Andreas and Liebschner, M. and Krause, C. and Heinrich, B. and Berger, Frank}, title = {Einfluss von Grenzfl{\"a}chen auf das dielektrische Verhalten von HG{\"U}-Isoliersystemen}, series = {ETG-Fachbericht 112}, booktitle = {ETG-Fachbericht 112}, publisher = {VDE}, address = {W{\"u}rzburg}, language = {de} } @inproceedings{KuechlerSchoberExneretal., author = {K{\"u}chler, Andreas and Schober, F. and Exner, W. and Krause, Ch. and Berger, Frank}, title = {Influence of Board Density on the Conductivity of Oi-Impregnated Pressboard for HVDC Insulation Systems}, series = {IEEE Electrical Insulation Conference}, booktitle = {IEEE Electrical Insulation Conference}, address = {Seattle, Washington, USA}, pages = {61 -- 64}, language = {en} } @article{KuechlerSchoberHarreretal., author = {K{\"u}chler, Andreas and Schober, F. and Harrer, S. and Berger, Frank and Liebschner, M. and Krause, Ch. and Exner, W.}, title = {Conductivity of Pressboard for HVDC Insulation Systems}, series = {IJECES International Journal of Electrical and Computer Engineering Systems}, volume = {4}, journal = {IJECES International Journal of Electrical and Computer Engineering Systems}, number = {2}, pages = {1 -- 7}, language = {en} } @inproceedings{WirthReumannKuechleretal., author = {Wirth, Isabell and Reumann, Andreas and K{\"u}chler, Andreas and Schnitzler, Tim and Langens, Achim and Berger, Frank and Zink, Markus H.}, title = {Steady-state and Transient Electrical Potential Distribution 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 Republic}, language = {en} } @article{ZinkKuechlerBerger, author = {Zink, Markus H. and K{\"u}chler, Andreas and Berger, Frank}, title = {Kompensation des Temperatureinflusses auf dielektrische Messungen im Zeitbereich zur Beschreibung von Isolierwerkstoffen}, series = {ETG-Fachtagung „Grenzfl{\"a}chen in elektrischen Isoliersystemen"}, journal = {ETG-Fachtagung „Grenzfl{\"a}chen in elektrischen Isoliersystemen"}, address = {Dresden}, language = {de} } @inproceedings{WirthSturmKuechleretal., author = {Wirth, Isabell and Sturm, Sebastian and K{\"u}chler, Andreas and Zink, Markus H. and Berger, Frank and Schnitzler, Tim}, title = {Ber{\"u}cksichtigung von Leitungs- und Polarisationsmechanismen in transienten FEM-Simulationen von HG{\"U}-Isoliersystemen}, series = {VDE-Hochspannungstechnik 2018, Berlin}, booktitle = {VDE-Hochspannungstechnik 2018, Berlin}, abstract = {The calculation of electrical field distributions in insulation systems for high voltage direct current (HVDC) transmission using the finite element method (FEM) usually only considers the dielectric properties in the form of permittivities and conductivities. Due to not sufficiently well simulated transient processes, state of the art is considering the polarization processes by equivalent network models. The application and implementation of polarization mechanisms in a FEM soft- ware closes this gap and allows calculating the electric field distribution more precisely. An implementation of additional differential equations, according to the RC-network model, describing the field dependent polarization mechanisms, are complementing the displacement and conduction current. Material equations and their parameters are determined by measuring the polarization and depolarization currents (PDC). These equations are necessary for both the RC-network models and the differential equations for the FEM. They can be adapted to the actual temperatures in the insulation system. Hence, the necessarily multidimensional electric field calculations of complex insulation systems with stationary or transient temperature-gradients are possible. The described calculation method is verified by reactionless fieldmill voltmeter measurements of transient voltage profiles at the grading foils of modified high voltage DC-bushings. A better accuracy is achieved for the simulation of transient and stationary potential distributions.}, language = {de} } @inproceedings{WirthReumannKuechleretal., author = {Wirth, Isabell and Reumann, Andreas and K{\"u}chler, Andreas and Zink, Markus H. and Berger, Frank and Langens, Achim and Schnitzler, Tim and Heil, B.}, title = {Measurement and simulation of transient field stresses and impacts on advanced insulation design and new test procedures for HVDC components}, series = {Cigre-Konferenz, Paris}, booktitle = {Cigre-Konferenz, Paris}, language = {en} } @article{ZinkKlipfelBergeretal., author = {Zink, Markus H. and Klipfel, V. and Berger, Frank and K{\"u}chler, Andreas and Voll, S.}, title = {Der Einfluss von Temperatur und Streukapazit{\"a}t auf diagnostische Kapazit{\"a}ts- und Verlustfaktormessungen von 400 kV-Hochspannungstransformatordurchf{\"u}hrungen}, series = {ETG-Fachtagung „Diagnostik elektrischer Betriebsmittel"}, journal = {ETG-Fachtagung „Diagnostik elektrischer Betriebsmittel"}, address = {Fulda}, language = {de} } @inproceedings{WirthHessdoerferKuechleretal., author = {Wirth, Isabell and Heßd{\"o}rfer, Nadja and K{\"u}chler, Andreas and Zink, Markus H. and Langens, Achim and Berger, Frank}, title = {Measurements and calculations of critical thermal and electrical stress conditions for HVDC bushings}, series = {20th International Symposium on High Voltage Engineering, Buenos Aires, 2017}, booktitle = {20th International Symposium on High Voltage Engineering, Buenos Aires, 2017}, language = {en} } @inproceedings{WirthKuechlerZinketal., author = {Wirth, Isabell and K{\"u}chler, Andreas and Zink, Markus H. and Berger, Frank and Langens, Achim}, title = {Elektrische Feldverteilung und Polarisationsstr{\"o}me in HG{\"U} Durchf{\"u}hrungen}, series = {Fachtagung Polymere Isolierstoffe und ihre Grenzfl{\"a}chen, Zittau, 2018}, booktitle = {Fachtagung Polymere Isolierstoffe und ihre Grenzfl{\"a}chen, Zittau, 2018}, language = {de} } @incollection{KuechlerSchoberHarreretal., author = {K{\"u}chler, Andreas and Schober, F. and Harrer, S. and Krause, Ch. and Berger, Frank}, title = {Einfluss von Temperatur und Ligningehalt auf die elektrische Leitf{\"a}higkeit von Pressspan als HG{\"U}-Isolierwerkstoff}, series = {6. RCC-Fachtagung „Werkstoffe zur Anwendung in der el. Energietechnik unter den besonderen Anforderungen der HG{\"U}"}, booktitle = {6. RCC-Fachtagung „Werkstoffe zur Anwendung in der el. Energietechnik unter den besonderen Anforderungen der HG{\"U}"}, address = {Berlin}, pages = {268 -- 273}, language = {de} } @incollection{KuechlerSchoberHarreretal., author = {K{\"u}chler, Andreas and Schober, F. and Harrer, S. and Wolfinger, T. and Krause, Ch. and Exner, W. and Berger, Frank}, title = {Leitf{\"a}higkeit von Pressspan als diagnostische Kenngr{\"o}ße f{\"u}r HG{\"U}-Betriebsmittel}, series = {ETG-Fachbericht 144}, booktitle = {ETG-Fachbericht 144}, publisher = {VDE}, address = {Berlin}, language = {de} } @incollection{KuechlerReumannWirthetal., author = {K{\"u}chler, Andreas and Reumann, Andreas and Wirth, Isabell and Langens, Achim and Berger, Frank}, title = {Erfassung transienter elektrischer Potentialverteilungen in thermisch hoch belasteten Gleichspannungsdurchf{\"u}hrungen}, series = {ETG-Fachbericht 144}, booktitle = {ETG-Fachbericht 144}, publisher = {VDE}, address = {Berlin}, abstract = {Mit Hilfe kapazitiver Steuerung k{\"o}nnen Durchf{\"u}hrungen hochspannungsf{\"u}hrende Leiter durch geerdete W{\"a}nde in Geb{\"a}uden oder Ger{\"a}ten f{\"u}hren. Bei zeitver{\"a}nderlichen Belastungen (Stoß-, Wechselspannungen) wird die gew{\"u}nschte Potentialaufteilung durch die Kapazit{\"a}ten zwischen den leitf{\"a}higen Steuerbel{\"a}gen erzwungen. Bei Gleichspannung ergibt sich eine resistive Steuerung, die bei homogener Leitf{\"a}higkeit des Isolierk{\"o}rpers eine prinzipiell gleichartige Potentialaufteilung ergibt. Durchf{\"u}hrungen sind jedoch thermisch hoch belastete Betriebsmittel, in denen starke Temperaturgradienten und in ihrer Folge starke Leitf{\"a}higkeitsgradienten entstehen, die zu einer erheblichen Verschiebung der Potentialverteilung f{\"u}hren k{\"o}nnen [1]. F{\"u}r Design und Diagnose ist das Verst{\"a}ndnis dieser bisher nur theoretisch erfassbaren Vorg{\"a}nge von großer Bedeutung. Deshalb wurden f{\"u}r experimentelle Untersuchungen zwei identische Durchf{\"u}hrungsk{\"o}rper hergestellt, die mit Temperaturf{\"u}hlern f{\"u}r thermische Messungen bzw. mit Anzapfungen f{\"u}r die Erfassung von elektrischen Potentialen ausger{\"u}stet wurden. Die identische Beheizung beider Leiterrohre erlaubt es, eine Korrelation gemessener thermischer und elektrischer Profile und Transienten herzustellen. F{\"u}r r{\"u}ckwirkungsfreie Messung der Gleichspannungspotentiale wurde ein Rotationsvoltmeter benutzt. Die Untersuchungen best{\"a}tigen das theoretisch erwartete thermisch-elektrische Verhalten und sie zeigen, dass erhebliche transiente und station{\"a}re elektrische Belastungen auftreten k{\"o}nnen, die im Zusammenhang mit thermischen Transienten und Belastungen gesehen werden m{\"u}ssen. Sie sind beim Design in Rechnung zu stellen und sie zeigen, dass die bei dielektrischen Diagnosemessungen erfassten Materialkenngr{\"o}ßen wichtige Aussagen {\"u}ber den elektrischen Belastungszustand der Durchf{\"u}hrung liefern k{\"o}nnen.}, language = {de} } @incollection{KuechlerZinkBerger, author = {K{\"u}chler, Andreas and Zink, M. and Berger, Frank}, title = {Kompensation des Temperatureinflusses auf dielektrische Messungen im Zeitbereich zur Beschreibung von Isolierwerkstoffen}, series = {ETG-Fachbericht 140}, booktitle = {ETG-Fachbericht 140}, publisher = {VDE}, address = {Dresden}, language = {de} }