@inproceedings{TargitayRothZinketal., author = {Targitay, Deniz and Roth, Lisa and Zink, Markus H. and K{\"u}chler, Andreas and Bier, Markus and Kobus, Maja and Geißler, Michael and Schlittler, Balz}, title = {An FEM simulation model of oil-pressboard insulating systems for HVDC transformers}, series = {23rd International Symposium on High Voltage Engineering (ISH 2023)}, booktitle = {23rd International Symposium on High Voltage Engineering (ISH 2023)}, publisher = {Institution of Engineering \& Technology}, pages = {7}, abstract = {In this contribution, a simulation model for the description of the nonlinear dielectric behaviour of an insulation system composed of mineral oil and oil-impregnated pressboard is presented. The model was verified by comparing the simulation results with electric field and current measurements. At the outset, the ideal case, where a homogeneous initial charge carrier distribution according to the definition of ohmic conductivity is present, is analysed to establish the preliminary foundations pertaining to a typical measurement. Following that, the influence of distinct charge carriers on the measured quantities are investigated by altering their parametrisations. In contrast to the ideal case, a real measurement reveals a current trend, that can be explained by an excess amount of initial charge carriers related to the oil-impregnated pressboard layers. Potential possibilities to the origin of the surplus are discussed. Furthermore, it is shown that the dissociable and intrinsic charge carriers alone can reconstruct the measured quantities in terms of the transient behaviour. This points out that, for the field strength studied here ( E ≤ 1 kV/mm ), the charging of the highly resistive pressboard barriers is dominated by the dissociation of charge carriers in the oil gaps.}, language = {en} } @book{Zink, author = {Zink, Markus H.}, title = {Zustandsbewertung betriebsgealterter Hochspannungstransformatordurchf{\"u}hrungen mit {\"O}l-Papier-Dielektrikum mittels dielektrischer Diagnose}, publisher = {Universit{\"a}tsverlag Ilmenau}, address = {Ilmenau}, language = {de} } @book{Zink, author = {Zink, Markus H.}, title = {Kerntechnik}, publisher = {Vogel Fachbuchverlag}, language = {de} } @book{Zink, author = {Zink, Markus H.}, title = {Kerntechnik}, publisher = {Vogel Fachbuchverlag}, language = {de} } @inproceedings{KuechlerKriegLalaetal., author = {K{\"u}chler, Andreas and Krieg, A. and Lala, G. and Schober, F. and Wiener, J. and Paulus, J. and Zink, Markus H. and Liebschner, M.}, title = {FEM model for describing the dielectric behavior of oil-impregnated pressboard under DC stresses}, series = {33rd International Conference "Science in Practice"}, booktitle = {33rd International Conference "Science in Practice"}, address = {Schweinfurt}, language = {en} } @inproceedings{HartmannHarrerDotterweichetal., author = {Hartmann, J{\"u}rgen and Harrer, S. and Dotterweich, C. and Zink, Markus H. and Hemberger, Frank and Ebert, Hans-Peter and Schnitzler, Tim}, title = {Phase change materials for use in thermally and electrically stressed insulation for high voltage applications}, series = {2016 IEEE Electrical Insulation Conference}, booktitle = {2016 IEEE Electrical Insulation Conference}, publisher = {IEEE}, isbn = {978-1-4673-8706-4}, pages = {605 -- 608}, abstract = {The temperature of high voltage equipment is often the limiting factor when transmitting electrical energy because the electrical insulation can get severely aged when the temperature is exceeding a certain limit. Hence, cooling has to be improved or heat generation must be reduced to avoid damage of the insulation. In this paper a new method was examined by investigating electrically insulating phase change materials which are able to store latent heat during a phase change from the solid to liquid state in times of high energy demand. To verify the electrically insulating properties of paraffins, one class of phase change materials, a special test cell was designed allowing the determination of breakdown voltage of phase change materials. The measurements on one paraffin sample proved the promising electrical insulating properties and it was shown that the breakdown voltage in the liquid state is comparable …}, 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{ZinkDotterweichHartmannetal., author = {Zink, Markus H. and Dotterweich, C. and Hartmann, J{\"u}rgen and Harrer, S. and Hemberger, F. and Ebert, Hans-Peter and Schnitzler, Tim}, title = {Phase Change Materials for Use in Thermally and Electrically Stressed Insulation for High Voltage Applications}, series = {IEEE Electrical Insulation Conference}, volume = {2016}, booktitle = {IEEE Electrical Insulation Conference}, pages = {605 -- 608}, 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{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{HartmannHarrerDotterweichetal., author = {Hartmann, J{\"u}rgen and Harrer, S. and Dotterweich, C. and Zink, Markus H.}, title = {On the conduction process of dielectric liquids based on mineral oil}, address = {Buenos Aires (Argentinien)}, 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} } @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{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} } @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{KochHohlochWirthetal., author = {Koch, Myriam and Hohloch, Jens and Wirth, Isabell and Sturm, Sebastian and Zink, Markus H. and K{\"u}chler, Andreas}, title = {Experimental and simulative analysis of the thermal behavior of high voltage cable joints}, series = {VDE-Hochspannungstechnik 2018, Berlin}, booktitle = {VDE-Hochspannungstechnik 2018, Berlin}, abstract = {Nowadays, cable systems are often preferred when deciding on the type of new transmission lines even in the high and extra high voltage range. One of the main reasons is the better public acceptance. In addition, the power to be transmitted in the grid is increasing leading to increased ohmic losses and thus, to higher thermal stress on the materials. The investigations in this contribution focus on cable joints, which represent important and decisive components of cable systems. In order to optimize the design and to ensure reliable operation over the entire service life, the temperature profile within these components is of special interest. For their detailed investigation, a test circuit was set up consisting of a cable section and sections with build-up stages of a cable joint. A large number of measuring points were defined also at points where no measurement is possible in normal operation. With a thermographic camera the surface temperature distributions were observed. With the laboratory setup temperature profiles under various load conditions were recorded. A detailed FEM model was built and verified with help of these measurements. The model permits the investigation of specific questions of cable systems such as the comparison of temperature loads resulting from normal operating conditions and of test procedures according to the relevant standards. Besides others the effect of stressing the insulation and sealing system by heating the inner conductor vs. heating from outside by surrounding water is discussed.}, 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} } @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{HopfWirthSturmetal., author = {Hopf, K. and Wirth, Isabell and Sturm, Sebastian and K{\"u}chler, Andreas and Zink, Markus H. and Langens, Achim}, title = {Temperature-dependent and anisotropic electrical conductivity of resin-impregnated paper}, series = {Power and Energy Student Summit, N{\"u}rnberg, 2017}, booktitle = {Power and Energy Student Summit, N{\"u}rnberg, 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} } @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{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} }