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



2023

5091.

[german] Zeller, Diana; Bohrmann-Linde, Claudia
Kritischer Umgang mit Videos im naturwissenschaftlichen Unterricht (KriViNat)
In Wilke, T.; Rubner, I., Editor, Band DiCE-Tagung 2023 - Digitalisation in Chemistry Education
Herausgeber: Friedrich-Schiller-Universität Jena, Institut für Anorganische und Analytische Chemie, Jena
2023

5090.

Botchev, M. A.; Knizhnerman, L. A.; Schweitzer, M.
Krylov subspace residual and restarting for certain second order differential equations
SIAM J. Sci. Comput. :S223-S253
2023

5089.

Frommer, Andreas; Kahl, Karsten; Schweitzer, Marcel; Tsolakis, Manuel
Krylov subspace restarting for matrix Laplace transforms
SIAM J. Matrix Anal. Appl., 44 (2) :693-717
2023

5088.

Frommer, Andreas; Kahl, Karsten; Schweitzer, Marcel; Tsolakis, Manuel
Krylov subspace restarting for matrix Laplace transforms
SIAM J. Matrix Anal. Appl., 44 (2) :693-717
2023

5087.

[german] Tausch, Michael W.
Licht und Farbe – ein Muss für den Chemieunterricht
CHEMKON, 30
2023

5086.

Gesell, Hendrik; Janoske, Uwe
Magnetohydrodynamic Analysis of Load Shifting in Hall-Héroult Cells
Journal of Sustainable Metallurgy :1--9
2023
Herausgeber: Springer International Publishing Cham

5085.

Matyokubov, Kh Sh; Ehrhardt, Matthias
Manakov system on metric graphs: Modeling the reflectionless propagation of vector solitons in networks
Physics Letters, Section A, 479 :128928
2023
Herausgeber: North-Holland

5084.

Matyokubov, Kh Sh; Ehrhardt, Matthias
Manakov system on metric graphs: Modeling the reflectionless propagation of vector solitons in networks
Physics Letters, Section A, 479 :128928
2023
Herausgeber: North-Holland

5083.

Ehrhardt, Matthias
Mathematical Analysis and a Nonstandard Scheme for a Model of the Immune Response against COVID-19
2023

5082.


Measurement of $t$-channel production of single top quarks and antiquarks in $pp$ collisions at 13 TeV using the full ATLAS Run 2 dataset
2023

5081.

Mayotte, Eric William; others
Measurement of the mass composition of ultra-high-energy cosmic rays at the Pierre Auger Observatory
PoS, ICRC2023 :365
2023

5080.

[german] Grandrath, Rebecca; Bohrmann-Linde, Claudia
Mit Lactase und Lactose zum elektrischen Strom - enzymatische Brennstoffzellen auf Filterpapierbasis für den Chemieunterricht.
CHEMKON, 30 (1) :37-41
Januar 2023

5079.

Jäschke, Jens; Skrepek, Nathanael; Ehrhardt, Matthias
Mixed-dimensional geometric coupling of port-Hamiltonian systems
Applied Mathematics Letters, 137 :108508
2023
Herausgeber: Pergamon

5078.

Jäschke, Jens; Skrepek, Nathanael; Ehrhardt, Matthias
Mixed-dimensional geometric coupling of port-Hamiltonian systems
Applied Mathematics Letters, 137 :108508
2023
Herausgeber: Pergamon

5077.

Jäschke, Jens; Skrepek, Nathanael; Ehrhardt, Matthias
Mixed-dimensional geometric coupling of port-Hamiltonian systems
Applied Mathematics Letters, 137 :108508
2023
Herausgeber: Pergamon

5076.

Tyshchenko, Andrey; Kozitskiy, Sergey; Kazak, Mikhail; Petrov, Pavel
Modern methods of sound propagation modelling based on the expansion of acoustic fields over normal modes
Acoustical Physics (accepted, to appear in 2023), 69 (5)
Juni 2023

5075.

Rajkovic, Michelle; Benter, Thorsten; Wissdorf, Walter
Molecular Dynamics-Based Modeling of Ion-Neutral Collisions in an Open Ion Trajectory Simulation Framework
Journal of the American Society for Mass Spectrometry, 34 (10) :2156—2165
Oktober 2023
ISSN: 1044-0305, 1879-1123

5074.

Klamroth, Kathrin; Stiglmayr, Michael; Sudhoff, Julia
Multi-objective matroid optimization with ordinal weights
Discrete Applied Mathematics, 335 :104-119
2023
ISSN: 0166-218X

5073.

Vinod, Vivin; Maity, Sayan; Zaspel, Peter; Kleinekathöfer, Ulrich
Multifidelity Machine Learning for Molecular Excitation Energies
J. Chem. Theory Comput., 19 (21) :7658-7670
2023

5072.

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
Preprint
2023

5071.

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
2023

5070.

Müller, Mats; Kemper, Svenja; Schlenkhoff, Andreas
Numerical modelling of the hydraulic capacity of grates inlets (OpenFOAM)
E-proceedings of the 40th IAHR World Congress in 2023 in Vienna, Austria.
2023

5069.

Ehrhardt, Matthias; Kozitskiy, Sergey B
On a generalization of the split-step Padé method to the case of unknown vector-functions
Preprint IMACM
2023
Herausgeber: Bergische Universität Wuppertal

5068.

Ehrhardt, Matthias; Kozitskiy, Sergey B
On a generalization of the split-step Padé method to the case of unknown vector-functions
Preprint IMACM
2023
Herausgeber: Bergische Universität Wuppertal

5067.

Farkas, Bálint; Jacob, Birgit; Schmitz, Merlin
On exponential splitting methods for semilinear abstract Cauchy problems
Integral Equations and Operator Theory, 95 :Paper No. 15
2023