Applied and Computational Mathematics (ACM)

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

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

Cooperation

Former and ongoing projects

Publications



2025

5442.

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, 1520-5851

5441.

Patel, Vivak; Maldonado, D Adrian; Melnichenko, Maksim; Pritchard, Nathaniel; Rao, Vishwas; Rebrova, Elizaveta; Sankararaman, Sriram; Schweitzer, Marcel
Scientific Applications Leveraging Randomized Linear Algebra
2025

5440.

Clément, François; Doerr, Carola; Klamroth, Kathrin; Paquete, Luís
Searching Permutations for Constructing Uniformly Distributed Point Sets
Proceedings of the National Academy of Sciences, 122 (14) :e2424464122
2025

5439.

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, 1879-1123

5438.

Palitta, Davide; Schweitzer, Marcel; Simoncini, Valeria
Sketched and truncated polynomial Krylov methods: Evaluation of matrix functions
Numer. Linear Algebra Appl., 32 :e2596
2025

5437.

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 2025

5436.

Arora, Sahiba; Mui, Jonathan
Smoothing of operator semigroups under relatively bounded perturbations
2025

5435.

Santos, Daniela Dos; Klamroth, Kathrin; Martins, Pedro; Paquete, Luís
Solving the Multiobejctive Quasi-Clique Problem
European Journal of Operational Research, 323 :409—424
2025

5434.

Gökkus, Yasemin
Spieleentwickung im Chemieunterricht. Auftakt einer Aktionsforschung
MNU-Journal, 03/2025 :182-190
2025

5433.

Hamadi, Majed; Mahdavi-Amiri, Nezam; Schweitzer, Marcel
Splitting methods based on the nonzero diagonal pattern for computing matrix functions
2025

5432.

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 2025

5431.

[german] Zeller, Diana; Ramella, Abigail; Mack, Nils; Schrader, Claudia; Bohrmann-Linde, Claudia
Virtual Reality im Unterricht – Potentiale und Herausforderungen beim Einsatz von VR im Chemieunterricht
MNU-Journal, 04/2025 :284-289
2025

5430.

[german] Kiesling, Elisabeth; Bohrmann-Linde, Claudia
Von der Leitlinie BNE zum bilingual-englischen Schülerlabor- Konzeption, Erprobung und Evaluation einer bilingualen Experimentierumgebung im Fach Chemie zum Thema Carbon Capture and Storage
In Andreas Keil, Annika Hanau und Julian Dietze (Hg.): BNE in der Lehrkräftebildung. Erkenntnisse aus Forschung und Praxis., Editor, BNE in der Lehrkräftebildung - Erkenntnisse aus Forschung und Praxis
Seite 327-344
Herausgeber: Waxmann
Mai 2025
327-344

ISBN: 978-3-8188-0035-2

5429.

[german] Zeller, Diana; Bohrmann-Linde, Claudia; Mack, Nils; Schrader, Claudia
VR-Lernsettings zum Thema Verbrennungsreaktionen. Ein interdisziplinäres Lehrprojekt zur Produktion von VR-Räumen durch Lehramtsstudierende
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 79-84
Herausgeber: Waxmann Verlag, Münster New York
2025
79-84

ISBN: ISBN 978-3-8188-0042-0

5428.

Elghazi, Bouchra; Jacob, Birgit; Zwart, Hans
Well-posedness of a class of infinite-dimensional port-Hamiltonian systems with boundary control and observation
Januar 2025

5427.

Testa, Filippo
Well-Posedness of the Hodge Wave Equation on a Compact Manifold
2025
2024

5426.


Oleanolic Acid-Derived High-Glass-Transition-Temperature Methacrylic Polymers
Sustainable Chemistry & Engineering, 12 :18499-18507
Dezember 2024
Herausgeber: ACS
ISSN: 2168-0485

5425.

Sinani, Mario; Palacios, Rafael; Wynn, Andrew
Capturing & Bounding Nonlinear Modal Energy Transfer for Geometrically Exact Beams using Semi-Definite Programming
EEE 63rd Conference on Decision and Control (CDC), 16-19 December
Dezember 2024

5424.

Klass, Friedemann; Gabbana, Alessandro; Bartel, Andreas
Perfectly Matched Layers and Characteristic Boundaries in Lattice Boltzmann: Accuracy vs Cost
AIAA Journal
Dezember 2024

5423.

Bohrmann-Linde, Claudia; Kiesling, Elisabeth; Brunnert, Rainer; Strippel, C.; Landau, R.; Geller, Heidrun
Bilingual Chemistry
In Claudia Bohrmann-Linde, Rainer Brunnert, Elisabeth Kiesling, Editor, Band 1
Herausgeber: Bergische Universität Wuppertal
November 2024

5422.

Aydonat, Simay; Campagna, Davide; Kumar, Sourabh; Storch, Sonja; Neudecker, Tim; Göstl, Robert
Accelerated Mechanochemical Bond Scission and Stabilization against Heat and Light in Carbamoyloxime Mechanophores
Journal of the American Chemical Society, 146 (46) :32117-32123
November 2024
ISSN: 0002-7863

5421.

Liu, Kang; Wang, Ziqi; Zuazua, Enrique
A Potential Game Perspective in Federated Learning
November 2024

5420.


Synthesis of N2-Substituted 1,2,3-Triazoles
Organic Letters, 26 :8816-8820
Oktober 2024
Herausgeber: ACS

5419.

Erbay, Mehmet; Jacob, Birgit; Morris, Kirsten; Reis, Timo; Tischendorf, Caren
Index concepts for linear differential-algebraic equations in finite and infinite dimensions
DAE Panel, 2
Oktober 2024

5418.

Vinod, Vivin; Zaspel, Peter
QeMFi: A Multifidelity Dataset of Quantum Chemical Properties of Diverse Molecules [dataset]
Oktober 2024