@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} } @inproceedings{WirthReumannZinketal., author = {Wirth, Isabell and Reumann, Andreas and Zink, Markus H. and K{\"u}chler, Andreas and Langens, Achim and Schnitzler, Tim}, title = {Messung elektrischer und thermischer Transienten an Hochspannungsgleichstromdurchf{\"u}hrungen}, series = {Highvolt Kolloquium, Dresden, 2015 (Poster)}, booktitle = {Highvolt Kolloquium, Dresden, 2015 (Poster)}, language = {de} } @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{KuechlerLiebschnerReumannetal., author = {K{\"u}chler, Andreas and Liebschner, M. and Reumann, Andreas and Krause, Ch. and Piovan, U. and Heinrich, B. and Fritsche, R. and Hoppe, J. and Langens, Achim and Titze, J.}, title = {Evaluation of conductivities and dielectric properties for highly stressed HVDC insulating materials}, series = {CIGR{\´E} Session 2010}, booktitle = {CIGR{\´E} Session 2010}, address = {Paris}, language = {en} } @incollection{KuechlerReumannLiebschneretal., author = {K{\"u}chler, Andreas and Reumann, Andreas and Liebschner, M. and Langens, Achim and Titze, J.}, title = {{\"U}berwachung von Hochspannungsdurchf{\"u}hrungen durch Online-Monitoring und dielektrische Diagnose gealterter OIP-Isolierungen}, series = {ETG-Fachbericht 119}, booktitle = {ETG-Fachbericht 119}, publisher = {VDE}, address = {D{\"u}sseldorf}, language = {de} } @incollection{KuechlerReumannLiebschneretal., author = {K{\"u}chler, Andreas and Reumann, Andreas and Liebschner, M. and B{\"o}hm, K. and Langens, Achim and Titze, J. and Heil, B.}, title = {Online Monitoring of Capacitance and Dissipation Factor of HV Bushings}, series = {16th ISH International Symposium on High Voltage Engineering}, booktitle = {16th ISH International Symposium on High Voltage Engineering}, address = {Cape Town}, language = {en} } @incollection{KuechlerReumannLiebschneretal., author = {K{\"u}chler, Andreas and Reumann, Andreas and Liebschner, M. and Langens, Achim and Titze, J.}, title = {Online Monitoring of Capacitance and Dissipation Factor Related to Ageing Research Results on OIP}, series = {54th IWK Internationales Wissenschaftliches Kolloquium Ilmenau}, booktitle = {54th IWK Internationales Wissenschaftliches Kolloquium Ilmenau}, address = {Ilmenau}, language = {en} } @incollection{KuechlerReumannBoehmetal., author = {K{\"u}chler, Andreas and Reumann, Andreas and B{\"o}hm, K. and Langens, Achim and Titze, J. and Heil, B.}, title = {Ageing of OIP Bushing Insulation at very High Temperatures}, series = {16th ISH International Symposium on High Voltage Engineering}, booktitle = {16th ISH International Symposium on High Voltage Engineering}, address = {Cape Town}, language = {en} } @incollection{KuechlerLiebschnerReumannetal., author = {K{\"u}chler, Andreas and Liebschner, M. and Reumann, Andreas and Fritsche, R. and R{\"o}sner, M. and Schenk, M. and Heinrich, B. and Krause, Ch. and Langens, Achim and Titze, J.}, title = {Bestimmung von Leitf{\"a}higkeiten und dielektrischen Eigenschaften hoch beanspruchter HG{\"U}-Isolierwerkstoffe}, series = {ETG-Fachbericht 125}, booktitle = {ETG-Fachbericht 125}, publisher = {VDE}, address = {K{\"o}ln}, language = {de} } @incollection{KuechlerBoehmReumannetal., author = {K{\"u}chler, Andreas and B{\"o}hm, K. and Reumann, Andreas and Langens, Achim and Krump, R. and Titze, J.}, title = {Untersuchung des Alterungsprozesses an den {\"O}l-Papier-Grenzfl{\"a}chen in Transformator-Durchf{\"u}hrungen}, series = {ETG-Fachbericht 112}, booktitle = {ETG-Fachbericht 112}, publisher = {VDE}, address = {W{\"u}rzburg}, language = {de} } @incollection{KuechlerLiebschnerBoehmetal., author = {K{\"u}chler, Andreas and Liebschner, M. and B{\"o}hm, K. and Reumann, Andreas and Krump, R. and Titze, J.}, title = {Online-monitoring of Capacity and Dissipation Factor of High Voltage Bushings at Service Temperature}, series = {15th ISH International Symposium on High Voltage Engineering}, booktitle = {15th ISH International Symposium on High Voltage Engineering}, address = {Ljubljana}, language = {en} } @incollection{KuechlerBoehmReumannetal., author = {K{\"u}chler, Andreas and B{\"o}hm, K. and Reumann, Andreas and Liebschner, M.}, title = {Online-Monitoring dielektrischer Kenngr{\"o}ßen von Hochspannungsdurchf{\"u}hrungen}, series = {Internationales Wissenschaftliches Kolloquium "Science in Practice"}, booktitle = {Internationales Wissenschaftliches Kolloquium "Science in Practice"}, address = {Schweinfurt}, language = {de} } @inproceedings{KriegLalaSchoberetal., author = {Krieg, Andreas and Lala, Gjergj and Schober, Fabian and Wiener, Johannes and Paulus, Johannes and K{\"u}chler, Andreas and Zink, Markus H. and Liebschner, Marcus}, title = {FEM model for describing the dielectric behavior of oil-impregnated pressboard under DC stresses}, series = {Papers of 33rd International Scientific Conference "Science in Practice"}, booktitle = {Papers of 33rd International Scientific Conference "Science in Practice"}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:863-opus-2609}, pages = {62 -- 66}, abstract = {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.}, 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} } @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} } @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} } @inproceedings{HochbruecknerSpiertzKuechleretal., author = {Hochbr{\"u}ckner, Benedikt and Spiertz, Martin and K{\"u}chler, Andreas and Zink, Markus and Steiner, T and Winkelmann, Erik and Kr{\"a}tzschmar, Karsten}, title = {Digital filtering methods for interferences on partial discharges under DC voltage}, language = {en} } @article{SchoberKuechlerKrause, author = {Schober, Fabian and K{\"u}chler, Andreas and Krause, Christoph}, title = {Oil conductivity - an important quantity for the design and the condition assessment of HVDC insulation systems}, series = {FHWS Science Journal}, volume = {1}, journal = {FHWS Science Journal}, number = {2}, address = {W{\"u}rzburg}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:863-opus-463}, pages = {59 -- 78}, abstract = {HVDC (high voltage direct current) transmission is a very effective way of power transmission and it is necessary to supply the worlds growing amount of energy. In HVDC equipment the major insulating materials are oil and pressboard. Oil conductivity is an important quantity for the design, the diagnosis and the condition assessment of HVDC insulation systems. Unfortunately, insulating oil has a strongly nonlinear conductivity which depends on various parameters (field strength, temperature, water content and ageing) and is time-dependent because of charge carrier drift processes. Measuring methods are required to provide the information necessary for the condition assessment of HVDC systems. Therefore, measurements of new and aged oils are compared and taken into account for a diagnosis of oil-filled HVDC insulation systems. Furthermore, today's standards are analyzed and compared to the so called PDC method. Relations between initial and steady-state conductivities at different temperatures, field strengths and for various oil types are presented and consequences for the condition assessment of insulation systems are discussed.}, language = {en} } @incollection{HochbruecknerSpiertzKuechleretal., author = {Hochbr{\"u}ckner, Benedikt and Spiertz, Martin and K{\"u}chler, Andreas and Zink, Markus and Steiner, Thomas and Winkelmann, Erik and Kr{\"a}tzschmar, Karsten}, title = {Digital Filtering Methods for Interferences on Partial Discharges Under DC Voltage}, isbn = {978-3-030-31675-4}, doi = {10.1007/978-3-030-31676-1_53}, pages = {560 -- 571}, language = {en} } @inproceedings{HochbruecknerKuechlerSpiertzetal., author = {Hochbr{\"u}ckner, Benedikt and K{\"u}chler, Andreas and Spiertz, Martin and Kr{\"a}tzschmar, Karsten and Zink, Markus}, title = {Comparison of Algorithms for Clustering of Partial Discharge Signals under DC Voltage}, doi = {10.1109/ICHVEPS47643.2019.9011062}, language = {en} } @inproceedings{KuechlerSchoberZinketal., author = {K{\"u}chler, Andreas and Schober, F. and Zink, M. and Liebschner, M. and Krause, Ch.}, title = {Diagnosis of HVDC Insulation Systems by use of Oil-conductivity Measuring Methods}, 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} } @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} } @article{KuechlerBellmHeroldetal., author = {K{\"u}chler, Andreas and Bellm, H. and Herold, J. and Schwab, A.}, title = {Rogowski-Spulen und Magnetfeldsensoren zur Messung transienter Str{\"o}me im Nanosekundenbereich}, series = {Archiv f{\"u}r Elektrotechnik}, volume = {68}, journal = {Archiv f{\"u}r Elektrotechnik}, pages = {63 -- 68}, language = {de} } @article{KuechlerBellmHeroldetal., author = {K{\"u}chler, Andreas and Bellm, H. and Herold, J. and Schwab, A.}, title = {Rogowski-Spulen und Magnetfeldsensoren zur Messung transienter Str{\"o}me im Nanosekundenbereich}, series = {Archiv f{\"u}r Elektrotechnik}, volume = {68}, journal = {Archiv f{\"u}r Elektrotechnik}, pages = {69 -- 74}, language = {de} }