@article{SturmPaulusKempkes2013, author = {Sturm, Sebastian and Paulus, Johannes and Kempkes, Joachim}, title = {Ermittlung der Widerstandsverluste in einem Energieseekabel mittels FEM}, 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-433}, pages = {79 -- 87}, year = {2013}, abstract = {Es werden die in Schirmung und Mantelung (Armierungsdr{\"a}hte) auftretenden Verluste in einem Energieseekabel mit einem Leiterquerschnitt von 1200 mm2 mittels FEM simuliert und den nach IEC 60287-1-1 kalkulierten gegen{\"u}bergestellt. Dabei wird zun{\"a}chst die Kalkulation der Verluste nach IEC Norm aufgezeigt, anschließend der Aufbau und die relevanten Stoffeigenschaften des Simulationsmodells erl{\"a}utert. Die anhand der FEM Simulation berechneten Verluste sind im Gesamten um etwa 25 \% geringer als nach IEC Norm. In Armierungsdr{\"a}hten betragen die berechneten Verluste lediglich ein Drittel der nach IEC Norm kalkulierten.}, 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{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{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} }