Magnetics

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.

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

2023: 5129.
Jäschke, Jens; Skrepek, Nathanael; Ehrhardt, Matthias
Mixed-dimensional geometric coupling of port-Hamiltonian systems
Applied Mathematics Letters, 137 :108508
2023
Herausgeber: Pergamon
DOI: 10.1016/j.aml.2022.108508; 5128.
Jäschke, Jens; Skrepek, Nathanael; Ehrhardt, Matthias
Mixed-dimensional geometric coupling of port-Hamiltonian systems
Applied Mathematics Letters, 137 :108508
2023
Herausgeber: Pergamon
DOI: 10.1016/j.aml.2022.108508; 5127.
Jäschke, Jens; Skrepek, Nathanael; Ehrhardt, Matthias
Mixed-dimensional geometric coupling of port-Hamiltonian systems
Applied Mathematics Letters, 137 :108508
2023
Herausgeber: Pergamon; 5126.
Klamroth, Kathrin; Stiglmayr, Michael; Sudhoff, Julia
Multi-objective matroid optimization with ordinal weights
Discrete Applied Mathematics, 335 :104-119
2023
ISSN: 0166-218X
DOI: 10.1016/j.dam.2022.07.017; 5125.
Vinod, Vivin; Maity, Sayan; Zaspel, Peter; Kleinekathöfer, Ulrich
Multifidelity Machine Learning for Molecular Excitation Energies
J. Chem. Theory Comput., 19 (21) :7658-7670
2023
DOI: 10.1021/acs.jctc.3c00882; 5124.
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
DOI: 10.48550/arXiv.2303.03390; 5123.
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; 5122.
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; 5121.
Finster, Rebecca; Kronschläger, Thomas; Grogorick, Linda; Robra-Bissantz, Susanne
Ok, gegen Cupids Pfeil hilft keine Firewall – Sichere(s) Daten durch ganzheitlichen Kompetenzaufbau
HMD - Praxis der Wirtschaftsinformatik, 61 :27–42
2023
DOI: doi.org/10.1365/s40702-023-01032-5; 5120.
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
Download; 5119.
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
Download; 5118.
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
DOI: 10.1007/s00020-023-02735-6; 5117.
Kraus, Konstantin; Klamroth, Kathrin; Stiglmayr, Michael
On the online path extension problem -- Location and routing problems in board games
2023
DOI: 10.48550/arXiv.2305.12898; 5116.
Bartel, Andreas; Günther, Michael; Jacob, Birgit; Reis, Timo
Operator splitting based dynamic iteration for linear differential-algebraic port-Hamiltonian systems
Accepted at Numerische Mathematik
2023; 5115.
Bartel, Andreas; Günther, Michael; Jacob, Birgit; Reis, Timo
Operator splitting based dynamic iteration for linear differential-algebraic port-Hamiltonian systems
Numerische Mathematik, 155 (1-2) :1–34
2023
Herausgeber: Springer New York
DOI: 10.1007/s00211-023-01369-5; 5114.
Bartel, Andreas; Günther, Michael; Jacob, Birgit; Reis, Timo
Operator splitting based dynamic iteration for linear differential-algebraic port-Hamiltonian systems
Numerische Mathematik, 155 (1-2) :1–34
2023
Herausgeber: Springer New York
DOI: 10.1007/s00211-023-01369-5; 5113.
Bartel, A.; Günther, M.; Jacob, Birgit; Reis, T.
Operator splitting based dynamic iteration for linear differential-algebraic port-Hamiltonian systems
Numer. Math., 155 (1-2) :1-34
2023
DOI: 10.1007/s00211-023-01369-5; 5112.
Farkas, Bálint; Jacob, Birgit; Reis, Timo; Schmitz, Merlin
Operator splitting based dynamic iteration for linear infinite-dimensional port-Hamiltonian systems
2023
DOI: 10.48550/arXiv.2302.01195; 5111.
Frommer, Andreas; Günther, Michael; Liljegren-Sailer, Björn; Marheineke, Nicole
Operator splitting for port-Hamiltonian systems
arXiv preprint arXiv:2304.01766
2023; 5110.
Frommer, Andreas; Günther, Michael; Liljegren-Sailer, Björn; Marheineke, Nicole
Operator splitting for port-Hamiltonian systems
Preprint
2023
DOI: 10.48550/arXiv.2304.01766; 5109.
Frommer, Andreas; Günther, Michael; Liljegren-Sailer, Björn; Marheineke, Nicole
Operator splitting for port-Hamiltonian systems
Preprint
2023
DOI: 10.48550/arXiv.2304.01766; 5108.
Bartel, Andreas; Diab, Malak; Frommer, Andreas; Günther, Michael
Operator splitting for semi-explicit differential-algebraic equations and port-Hamiltonian DAEs
Preprint
2023
DOI: 10.48550/arXiv.2308.16736; 5107.
Bartel, Andreas; Diab, Malak; Frommer, Andreas; Günther, Michael
Operator splitting for semi-explicit differential-algebraic equations and port-Hamiltonian DAEs
Preprint
2023
DOI: 10.48550/arXiv.2308.16736; 5106.
Doganay, Onur Tanil; Klamroth, Kathrin; Lang, Bruno; Stiglmayr, Michael; Totzeck, Claudia
Optimal control for port-Hamiltonian systems and a new perspective on dynamic network flow problems
2023
DOI: 10.48550/arXiv.2303.15082; 5105.
Klamroth, Kathrin; Stiglmayr, Michael; Sudhoff, Julia
Ordinal optimization through multi-objective reformulation
European Journal of Operational Research, 311 (2) :427-443
2023
ISSN: 0377-2217
DOI: https://doi.org/10.1016/j.ejor.2023.04.042

Computational Magnetics

Research Questions

Cooperation

Former and ongoing projects

Publications

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5126.

5125.

5124.

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5119.

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