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
5491.
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
315-3255475.
Khosrawi-Rad, Bijan; Keller, Paul; Grogorick, Linda; Benner, Dennis; Janson, Andreas; Robra-Bissantz, Susanne
Let's Play with AI! A 2x2 Experiment on Collaborative vs. Competitive Game Elements for Pedagogical Conversational Agents
Pre-ICIS SIG Services Workshop on Synergizing Service Ecosystems with AI
Bangkok, Thailand
20255474.
Schmitz, Denise
LinkedIn-Posts zur Jahrestagung
Nachhaltige IT und Alternativen zu Big Tech, 49
2025
Herausgeber: Gesellschaft für Informatik e.V.5473.
[german] Cornelius, Soraya; Bohrmann-Linde, Claudia
Motivieren mit (Teil-)Aufgaben zur Erklärvideoproduktion im Chemieunterricht
In Johannes Huwer, Timm Wilke, Amitabh Banerji, Editor, Band Progress in Digitalisation in Chemistry Education 2024. Digitales Lehren und Lernen an Hochschule und Schule im Fach Chemie
Seite 37-42
Herausgeber: Waxmann-Verlag, Münster New York
2025
37-42ISBN: 978-3-8188-0042-0
5472.
Finster, Rebecca; Grogorick, Linda; Robra-Bissantz, Susanne
Navigation im Cyberraum: Die NIS2-Umsetzung in der öffentlichen Verwaltung - mit KOMPASS und SEXTANT
Fachtagung Rechts- und Verwaltungsinformatik (RVI)
Hamburg
20255471.
Schweitzer, Marcel
Near instance optimality of the Lanczos method for Stieltjes and related matrix functions
SIAM J. Matrix Anal. Appl., 46 :1846-1865
20255470.
Bolten, Matthias; Doganay, Onur Tanil; Gottschalk, Hanno; Klamroth, Kathrin
Non-convex shape optimization by dissipative Hamiltonian flows
Engineering Optimization, 57 :384--403
20255469.
Beck, Christian; Jentzen, Arnulf; Kleinberg, Konrad; Kruse, Thomas
Nonlinear Monte Carlo Methods with Polynomial Runtime for Bellman Equations of Discrete Time High-Dimensional Stochastic Optimal Control Problems
Appl. Math. Optim., 91 (1) :26
20255468.
Arlinghaus, Clarissa Sabrina; Schmitz, Denise
NRW vernetzt sich – Neue Regionalgruppe Frauen und Informatik gestartet
Nachhaltige IT und Alternativen zu Big Tech, 49
2025
Herausgeber: Gesellschaft für Informatik e.V.5467.
Abel, Ulrich; Acu, Ana Maria; Heilmann, Margareta; Raşa, Ioan
On some Cauchy problems and positive linear operators
Mediterranean Journal of Mathematics, 22
2025