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
5416.
Bolten, Matthias; Doganay, Onur Tanil; Gottschalk, Hanno; Klamroth, Kathrin
Non-convex shape optimization by dissipative Hamiltonian flows
Engineering Optimization, 57 :384--403
20255415.
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
20255414.
Figueira, José Rui; Klamroth, Kathrin; Stiglmayr, Michael; Sudhoff Santos, Julia
On the Computational Complexity of Multi-Objective Ordinal Unconstrained Combinatorial Optimization
Operations Research Letters
20255413.
Löhken, Lara; Stiglmayr, Michael
On the multiobjective cable-trench problem
Journal of Combinatorial Optimization, 49 (55)
20255412.
Lorenz, Jan; Zwerschke, Tom; Günther, Michael; Schäfers, Kevin
Operator splitting for coupled linear port-Hamiltonian systems
Applied Mathematics Letters, 160 :109309
2025
Herausgeber: Elsevier5411.
Lorenz, Jan; Zwerschke, Tom; Günther, Michael; Schäfers, Kevin
Operator splitting for coupled linear port-Hamiltonian systems
Applied Mathematics Letters, 160 :109309
2025
Herausgeber: Elsevier5410.
Sinani, Mario; Wynn, Andrew; Palacios, Rafael
Physics-Informed Data-Driven Modelling of Nonlinear Aerodynamic Forces of the Pazy Wing
AIAA SciTech Forum, 6-10 January
01 20255409.
Vinod, Vivin; Lyu, Dongyu; Ruth, Marcel; R. Schreiner, Peter; Kleinekathöfer, Ulrich; Zaspel, Peter
Predicting Molecular Energies of Small Organic Molecules With Multi-Fidelity Methods
J. Comp. Chem., 46 (6) :e70056
20255408.
[german] Zeller, Diana; Bohrmann-Linde, Claudia; Mack, Nils; Schrader, Claudia
Produktion eigener VR-Lernsettings im Projekt FoPro-VR. Ein interdisziplinärer Lehransatz für die Lehramtsausbildung
In Mrohs, Lorenz; Franz, Julia; Herrmann, Dominik; Lindner, Konstantin; Staake, Thorsten, Editor, Digitales Lehren und Lernen an der Hochschule. Strategien - Bedingungen - Umsetzung
Seite 191-204
Herausgeber: transcript, Bielefeld
2025
191-204ISBN: 9783839471203
5407.
Vinod, Vivin; Zaspel, Peter
QeMFi: A Multifidelity Dataset of Quantum Chemical Properties of Diverse Molecules
Sci. Data, 12 (1) :202
2025
Herausgeber: Nature Publishing Group
ISSN: 2052-44635406.
Xue, Chaoyang; Chen, Hui; McGillen, Max R.; Su, Hang; Cheng, Yafang; Kleffmann, Jörg; Li, Guo; Cazaunau, Mathieu; Colomb, Aurélie; Sciare, Jean; DeWitt, Langley; Marchand, Nicolas; Sarda-Esteve, Roland; Petit, Jean-Eudes; Kukui, Alexandre
Role of Heterogeneous Reactions in the Atmospheric Oxidizing Capacity in Island Environments
Environmental Science & Technology, 59 (6) :3153—3164
Februar 2025
ISSN: 0013-936X, 1520-58515405.
Clément, François; Doerr, Carola; Klamroth, Kathrin; Paquete, Luís
Searching Permutations for Constructing Uniformly Distributed Point Sets
PNAS
20255404.
Heintz, Chris; Kersten, Hendrik; Benter, Thorsten; Wissdorf, Walter
Signatures of Charged Droplets from ESI: A Statistical Analysis of Non-summed Mass Spectra Compared to APCI
Journal of the American Society for Mass Spectrometry, 36 (4) :839—849
April 2025
ISSN: 1044-0305, 1879-11235403.
Palitta, Davide; Schweitzer, Marcel; Simoncini, Valeria
Sketched and truncated polynomial Krylov methods: Evaluation of matrix functions
Numer. Linear Algebra Appl., 32 :e2596
20255402.
Liu, Qian; Yanchang, Zhang; Zuan, Wang; Wang, Miao; Zhao, Xiaowei
Small-signal stability of sequence-decomposed grid-forming IBRs with DC-link voltage dynamics
Februar 20255401.
Arora, Sahiba; Mui, Jonathan
Smoothing of operator semigroups under relatively bounded perturbations
20255400.
Santos, Daniela Dos; Klamroth, Kathrin; Martins, Pedro; Paquete, Luís
Solving the Multiobejctive Quasi-Clique Problem
European Journal of Operational Research, 323 :409—424
20255399.
Elghazi, Bouchra; Jacob, Birgit; Zwart, Hans
Well-posedness of a class of infinite-dimensional port-Hamiltonian systems with boundary control and observation
Januar 20255398.
Acu, A.M.; Heilmann, Margareta; Raşa, I.
Convergence of linking Durrmeyer type modifications of generalized Baskatov operators
Bulleting of the Malaysian Math. Sciences Society5397.
Ehrhardt, Matthias
Ein einfaches Kompartment-Modell zur Beschreibung von Revolutionen am Beispiel des Arabischen Frühlings5396.
Günther, Michael
Einführung in die Finanzmathematik5395.
Al{\i}, G; Bartel, A
Electrical RLC networks and diodes5394.
Gjonaj, Erion; Bahls, Christian Rüdiger; Bandlow, Bastian; Bartel, Andreas; Baumanns, Sascha; Belzen, F; Benderskaya, Galina; Benner, Peter; Beurden, MC; Blaszczyk, Andreas; others
Feldmann, Uwe, 143 Feng, Lihong, 515 De Gersem, Herbert, 341 Gim, Sebasti{\'a}n, 45, 333
MATHEMATICS IN INDUSTRY 14 :5875393.
Ehrhardt, Matthias
für Angewandte Analysis und Stochastik5392.
Ehrhardt, Matthias; Günther, Michael; Striebel, Michael
Geometric Numerical Integration Structure-Preserving Algorithms for Lattice QCD Simulations