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
5525.
Asya, Berçin V.; Wang, Sitao; Euchler, Eric; Khiêm, Vu Ngoc; Göstl, Robert
Optical Force Probes for Spatially Resolved Imaging of Polymer Damage and Failure
Aggregate, 6 (4) :e70014
April 2025
ISSN: 2692-45605524.
Hahmann, Johannes; Schüpp, Boris N.; Ishaqat, Aman; Selvakumar, Arjuna; Göstl, Robert; Gräter, Frauke; Herrmann, Andreas
Sequence-specific, mechanophore-free mechanochemistry of DNA
Chem, 11 (4) :102376
April 2025
ISSN: 2451-9294, 2451-93085523.
Rajkovic, Michelle; Benter, Thorsten; Wissdorf, Walter
Investigation of Surface-Induced Dissociation Processes via Molecular Dynamics Simulations of Wall Collisions of Large Droplets Produced by Electrospray Ionization
Journal of the American Society for Mass Spectrometry, 36 (4) :760—770
April 2025
ISSN: 1044-0305, 1879-11235522.
Ocqueteau, Vicente; Tucsnak, Marius
On an Initial Value Problem Describing the Small Oscillations of a Floating Cylinder
April 20255521.
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, 1879-11235520.
Kiesling, Elisabeth
Unterrichtsmaterial Kreislaufwirtschaft - Den Kreislauf in Schwung bringen: Arbeitsblatt: 2.4 Carbon Capture and Stoage und Experiment: 2.5 Modellversuch zur Speicherung von Kohlenstoffdioxid in Kohleflözen
In Dr. Karl Hübner, Prof. Dr. Bernd Ralle, Editor
Herausgeber: Fonds der Chemischen Industrie im Verband der Chemischen Industrie e. V. (FCI)
April 20255519.
Bensberg, Kathrin; Gómez-Suárez, Adrián; Kirsch, S. F.
Solid-Supported Iodine(V) Reagents in Organic Synthesis
Chemistry - A European Journal, 31 :e202500670
März 2025
Herausgeber: Wiley
ISSN: 1521-37655518.
[german] Grandrath, Rebecca; Wiebel, Michelle; Bensberg, Kathrin; Schebb, Nils Helge; Kirsch, Stefan F.; Bohrmann-Linde, Claudia
Aus der Schale in die Schule
Nachrichten aus der Chemie, 73 (3) :10-12
März 20255517.
Storch, Sonja; Campagna, Davide; Aydonat, Simay; Göstl, Robert
Mechanochemical generation of nitrogen-centred radicals for the formation of tertiary amines in polymers
RSC Mechanochemistry, 2 (2) :240-245
März 20255516.
Grandrath, Rebecca; Wiebel, Michelle; Bensberg, Kathrin; Schebb, Nils Helge; Kirsch, S. F.; Bohrmann-Linde, Claudia
Aus der Schale in die Schule
Nachrichten aus der Chemie, 73 :10-12
Februar 2025
Herausgeber: Wiley
ISSN: 1868-00545515.
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, 1520-58515514.
Liu, Qian; Yanchang, Zhang; Zuan, Wang; Wang, Miao; Zhao, Xiaowei
Small-signal stability of sequence-decomposed grid-forming IBRs with DC-link voltage dynamics
IEEE Transactions on Power Electronics,, 40 (2) :2971-2986,
Februar 20255513.
Cornelius, Soraya
„Erklärvideos erklären“- Entwicklung und Erprobung eines interaktiven und digitalen Selbstlernbuchs zum schrittweisen Kompetenzerwerb für die Erklärvideoproduktion im Chemieunterricht (explorative Studie)
20255512.
Zeller, Diana; Bohrmann-Linde, Claudia
„Hallo, ich bin Fritz Haber – oder?“ Material zur Förderung der KI-Kompetenz im Chemieunterricht
Chemie & Schule, 40/4 :24-28
20255511.
Krieger, Emil; Schweitzer, Marcel
A general framework for Krylov ODE residuals with applications to randomized Krylov methods
20255510.
Lopes, Gonçalo; Klamroth, Kathrin; Paquete, Luís
A greedy hypervolume polychotomic scheme for multiobjective combinatorial optimization
Computers & Operations Research, 183 :107140
2025
ISSN: 0305-05485509.
Clevenhaus, A.; Totzeck, C.; Ehrhardt, M.
A Space Mapping approach for the calibration of financial models with the application to the Heston model
20255508.
Gaul, Daniela; Klamroth, Kathrin; Pfeiffer, Christian; Stiglmayr, Michael; Schulz, Arne
A Tight Formulation for the Dial-a-Ride Problem
European Journal of Operational Research, 321 (2) :363-382
2025
ISSN: 0377-22175507.
Bauß, Julius; Stiglmayr, Michael
Adapting Branching and Queuing for Multi-objective Branch and Bound
In Voigt, G., Fliedner, M., Haase, K., Brüggemann, W., Hoberg, K., Meissner, J., Editor, Operations Research Proceedings 2023. OR 2023. Lecture Notes in Operations Research
In Voigt, G., Fliedner, M., Haase, K., Brüggemann, W., Hoberg, K., Meissner, J., Editor
Herausgeber: Springer, Cham
20255506.
Könen, David; Stiglmayr, Michael
An output-polynomial time algorithm to determine all supported efficient solutions for multi-objective integer network flow problems
Discrete Applied Mathematics, 376 :1-14
2025
Herausgeber: Elsevier BV
ISSN: 0166-218X5505.
Frommer, Andreas; Rinelli, Michele; Schweitzer, Marcel
Analysis of stochastic probing methods for estimating the trace of functions of sparse symmetric matrices
Math. Comp., 94 :801-823
20255504.
Hoffe, Leon; Ulutas, Berna; Klamroth, Kathrin; Bracke, Stefan
Assessing the effectiveness and efficiency of selected solution approaches for two-dimensional stock cutting problems (Part III): Hybrid Approach For Printed Circuit Boards
AUTOMATION 2025: Conference on Automation — Innovations and Future Perspectives
20255503.
Schmitz, Denise
Auswirkungen von Fortbildungen zur informatischen Bildung auf den Berufsalltag von Lehrkräften
NakoDI -Nachwuchskonferenz der Didaktik der Informatik
Morschach, Schweiz
2022
20255502.
Hilbig, André
Barrieren im Informatikunterricht identifizieren und auflösen
NakoDI -Nachwuchskonferenz der Didaktik der Informatik
Morschach, Schweiz
2022
Gesellschaft für Informatik
20255501.
Vinod, Vivin; Zaspel, Peter
Benchmarking data efficiency in Δ-ML and multifidelity models for quantum chemistry
The Journal of Chemical Physics, 163 (2) :024134
2025
ISSN: 0021-9606
