Computational Magnetics
Many electro-technical devices such as e.g. printed circuit boards, electrical drives and antenna systems can be simulated on the basis of electrical circuits. However, the increasing frequencies and the decreasing size force designers to account for wave propagation effects, eddy-current effects, ferromagnetic saturation and hysteresis. For wave propagation effects and eddy-current effects, the results of stand-alone field simulation can be represented by an order-reduced equivalent model, which is then inserted in the overall circuit model. The representation of field-dependent nonlinearities and hysteresis effects, however, is not straightforward.
2D Simulation of a Transformer
The coupled field and circuit simulation becomes troublesome when a large number of time steps is required. This occurs when e.g. simulating an electrical drive where the machine requires 10 periods of 50 Hz to reach nominal speed whereas the switching of the Insulated Gate Bipolar Transistors in the frequency converter switches at 20 kHz, necessitating a time steps in the order of a microsecond to be used in the simulation. Since the field model consists typically of a few million degrees of freedom, all those unknowns have to be solved in every time step. Fortunately, the relevant time constants in electrical-energy converter are in the range 50 Hz. Hence the field model does not have to be time-stepped at the same rate as the circuit model, in which fast switches are present. The use of adaptive multirate time-integration schemes can reduce the numerical complexity of the problem substantially.
Research Questions
- Efficiency of the time-integration for field devices in pulsed circuits (multirate, dynamic iteration)
- DAE-index of the coupled system
- Existence and Uniqueness of the solution
Cooperation
- Herbert De Gersem, Katholieke Universiteit Leuven
- Markus Clemens, Bergische Universität Wuppertal
- Sascha Baumanns, Universität zu Köln
Former and ongoing projects
Publications
- 2025
5500.
Hellmig, Lutz; Burk, Steffen; Hennecke, Martin; Herper, Henry; Hilbig, André; Michaeli, Tilman; Mittag, Alexander; Pasternak, Arno; Puhlmann, Hermann; Röhner, Gerhard; Rücker, Michael; Schmalfeldt, Thomas; Spalteholz, Wolf; Stechert, Peer
Bildungsstandards Informatik für die Sekundarstufe I – Empfehlungen der Gesellschaft für Informatik
Herausgeber: Gesellschaft für Informatik e.V.
20255499.
Kiesling, Elisabeth; Bohrmann-Linde, Claudia
Carbon Capture and Storage - Nachweis von adsorbiertem Kohlenstoffdioxid
Naturwissenschaften im Unterricht Chemie, 1/25 :Versuchskarteikarte
20255498.
Clément, François; Doerr, Carola; Klamroth, Kathrin; Paquete, Luís
Constructing Optimal Star Discrepancy Sets
accepted in Proceedings of the AMS
20255497.
Diaz, Ignacio; Gorrec, Yann Le; Wu, Yongxin
Control Oriented Modular Modelling of a Floating Wind Turbine: The Port-Hamiltonian Approach
IFAC-PapersOnLine, 59 (8) :125-130
20255496.
Schaller, Manuel; Schmitz, Merlin; Jacob, Birgit; Farkas, Bálint
Dissipativity-based time domain decomposition for optimal control of hyperbolic {PDE}s
20255495.
Lachetta, Michael; Schmitz, Denise; Morawski, Michael; Humbert, Ludger; Kuckuck, Miriam
Einschätzungen von Grundschullehrkräften zur Relevanz von informatischer Bildung in der Grundschule
Seite 93-109
Herausgeber: Verlag Julius Klinkhardt, Bad Heilbrunn
2025
93-1095494.
Holzenkamp, Matthias; Lyu, Dongyu; Kleinekathöfer, Ulrich; Zaspel, Peter
Evaluation of uncertainty estimations for Gaussian process regression based machine learning interatomic potentials.
Machine Learning: Science and Technology
20255493.
Lyu, Dongyu; Vinod, Vivin; Holzenkamp, Matthias; Holtkamp, Yannick M.; Maity, Sayan; Salazar, Carlos R.; Kleinekathöfer, Ulrich; Zaspel, Peter
Excitation Energy Transfer between Porphyrin Dyes on a Clay Surface: A study employing Multifidelity Machine Learning.
Adv. Theory Simul., 8 (11) :e00271
20255492.
Song, Yongcun; Wang, Ziqi; Zuazua, Enrique
FedADMM-InSa: An Inexact and Self-Adaptive ADMM for Federated Learning
Neural Network, 181
Januar 20255491.
Kienitz, J; Moodliyar, L
Gaussian views explained
Wilmott, 2025 (135) :72–77
2025
Herausgeber: Wilmott Magazine5490.
Xu, Zhuo; Tucsnak, Marius
Global Exponential Stabilization for a Simplified Fluid-Particle Interaction System
Januar 20255489.
Bartel, Andreas; Schaller, Manuel
Goal-oriented time adaptivity for port-Hamiltonian systems
Journal of Computational and Applied Mathematics, 461 :116450
2025
ISSN: 0377-04275488.
Schmitz, Denise
Grundschullehrkräfte zwischen informatischer Bildung und Medienbildung
In Jan Grey, Denise Schmitz, Inga Gryl, Alexander Best, Miriam Kuckuck, Ludger Humbert, Editor
Seite 41-50
Herausgeber: Verlag Julius Klinkhardt, Bad Heilbrunn
2025
41-505487.
Grey, Jan; Schmitz, Denise; Gryl, Inga; Best, Alexander; Kuckuck, Miriam; Humbert, Ludger
Herausforderungen und Möglichkeiten informatischer Bildung in der Grundschule
In Jan Grey, Denise Schmitz, Inga Gryl, Alexander Best, Miriam Kuckuck, Ludger Humbert, Editor
Seite 7-23
Herausgeber: Verlag Julius Klinkhardt, Bad Heilbrunn
2025
7-235486.
Schäfers, Kevin; Finkenrath, Jacob; Günther, Michael; Knechtli, Francesco
Hessian-free force-gradient integrators
Computer Physics Communications, 309 :109478
2025
ISSN: 0010-46555485.
Schäfers, Kevin; Finkenrath, Jacob; Günther, Michael; Knechtli, Francesco
Hessian-free force-gradient integrators
Computer Physics Communications, 309 :109478
2025
ISSN: 0010-46555484.
Schäfers, Kevin; Finkenrath, Jacob; Günther, Michael; Knechtli, Francesco
Hessian-free force-gradient integrators and their application to lattice QCD simulations
PoS, LATTICE2024 :025
20255483.
Schäfers, Kevin; Finkenrath, Jacob; Günther, Michael; Knechtli, Francesco
Hessian-free force-gradient integrators and their application to lattice QCD simulations
PoS, LATTICE2024 :025
20255482.
Krhac, Kaja; Schuller, Frederic P.; Stramigioli, Stefano
Hybrid Schrödinger-Liouville and projective dynamics
IFAC-PapersOnLine, 59 (8) :208-213
20255481.
Shaju, K.; Laepple, T.; Hirsch, N.; Zaspel, P.
Ice borehole thermometry: Sensor placement using greedy optimal sampling
Geoscientific Instrumentation, Methods and Data Systems, 14 (2) :459—474
20255480.
Brinda, Torsten; Diethelm, Ira; Dittert, Nadine; Humbert, Ludger; Kramer, Matthias; Losch, Daniel; Schmitz, Denise
Informatics Competencies for All Teachers - Development of Recommendations for Teacher Education
OCCE 2024
Bournemouth, UK
20255479.
Bergner, Nadine; Humbert, Ludger; Schmitz, Denise; Fricke, Martin
Informatik kommt in die Grundschule
In Jan Grey, Denise Schmitz, Inga Gryl, Alexander Best, Miriam Kuckuck, Ludger Humbert, Editor
Seite 231-249
Herausgeber: Verlag Julius Klinkhardt, Bad Heilbrunn
2025
231-2495478.
Hilbig, André; Schmitz, Denise
Informatikdidaktische Sicht auf Barrierefreiheit als Unterrichts- und Forschungsgegenstand
INFOS 2025 – 21. GI-Fachtagung Informatik und Schule
Stoos, Schweiz
20255477.
Vinod, Vivin; Zaspel, Peter
Investigating Data Hierarchies in Multifidelity Machine Learning for Excitation Energies
J. Chem. Theory Comput., 21 (6) :3077-3091
20255476.
[german] Grandrath, Rebecca; Orhan, Nalan; Bohrmann-Linde, Claudia
Konzeption einer Projektwoche zu den Themen Food Waste und Food Loss für die gymnasiale Oberstufe
In Andreas Keil, Annika Hanau und Julian Dietze (Hg.): BNE in der Lehrkräftebildung. Erkenntnisse aus Forschung und Praxis., Editor
Seite 315-325
Herausgeber: Waxmann
2025
315-325