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
- 2022
4916.
Edeko, Nikolai; Kreidler, Henrik; Nagel, Rainer
A dynamical proof of the van der Corput inequality
Dynamical Systems, 37 :648-665
20224915.
Hermle, Patrick; Kreidler, Henrik
A Halmos-von Neumann theorem for actions of general groups
20224914.
Budde, Christian; Dobrick, Alexander; Glück, Jochen; Kunze, Markus
A monotone convergence theorem for strong Feller semigroups
20224913.
Ehrhardt, Matthias; Günther, Michael
A neural network enhanced weighted essentially non-oscillatory method for nonlinear degenerate parabolic equations
Physics of Fluids, 34 (2) :026604
2022
Herausgeber: AIP Publishing4912.
Ehrhardt, Matthias; Günther, Michael
A neural network enhanced weighted essentially non-oscillatory method for nonlinear degenerate parabolic equations
Physics of Fluids, 34 (2) :026604
2022
Herausgeber: AIP Publishing4911.
Ehrhardt, Matthias; Günther, Michael
A neural network enhanced weighted essentially non-oscillatory method for nonlinear degenerate parabolic equations
Physics of Fluids, 34 (2) :026604
2022
Herausgeber: AIP Publishing4910.
A neural network enhanced weighted essentially non-oscillatory method for nonlinear degenerate parabolic equations
Physics of Fluids, 34 (2) :026604
2022
Herausgeber: AIP Publishing LLC4909.
Klass, Friedemann; Gabbana, Alessandro; Bartel, Andreas
A non-reflecting boundary condition for multispeed lattice Boltzmann methods
In Ehrhardt, Matthias and Günther, Michael, Editor, Progress in Industrial Mathematics at ECMI 2021ausMathematics in Industry, Seite 447–453
In Ehrhardt, Matthias and Günther, Michael, Editor
Herausgeber: Springer Cham
20224908.
Klass, Friedemann; Gabbana, Alessandro; Bartel, Andreas
A non-reflecting boundary condition for multispeed lattice Boltzmann methods
In Ehrhardt, Matthias and Günther, Michael, Editor, Progress in Industrial Mathematics at ECMI 2021ausMathematics in Industry, Seite 447–453
In Ehrhardt, Matthias and Günther, Michael, Editor
Herausgeber: Springer Cham
20224907.
Klass, Friedemann; Gabbana, Alessandro; Bartel, Andreas
A non-reflecting boundary condition for multispeed lattice Boltzmann methods
In Ehrhardt, Matthias and Günther, Michael, Editor, Progress in Industrial Mathematics at ECMI 2021ausMathematics in Industry, Seite 447–453
In Ehrhardt, Matthias and Günther, Michael, Editor
Herausgeber: Springer Cham
20224906.
Klass, Friedemann; Gabbana, Alessandro; Bartel, Andreas
A non-reflecting boundary condition for multispeed lattice Boltzmann methods
In M. Ehrhardt and M. Günther, Editor, Accepted at Progress in Industrial Mathematics at ECMI 2021
Herausgeber: Springer-Verlag, Berlin
2022ISBN: 978-3-031-11817-3
4905.
Ehrhardt, Matthias
A Nonstandard Finite Difference Scheme for a Time-Fractional Model of Zika Virus Transmission
20224904.
Treibert, Sarah; Brunner, Helmut; Ehrhardt, Matthias
A nonstandard finite difference scheme for the SVICDR model to predict COVID-19 dynamics
Mathematical Biosciences and Engineering, 19 (2) :1213–1238
2022
Herausgeber: AIMS Press4903.
Treibert, Sarah; Brunner, Helmut; Ehrhardt, Matthias
A nonstandard finite difference scheme for the SVICDR model to predict COVID-19 dynamics
Mathematical Biosciences and Engineering, 19 (2) :1213–1238
2022
Herausgeber: AIMS Press4902.
Treibert, Sarah; Brunner, Helmut; Ehrhardt, Matthias
A nonstandard finite difference scheme for the SVICDR model to predict COVID-19 dynamics
Math. Biosci. Eng, 19 (2) :1213--1238
20224901.
Glück, Jochen
A note on the spectrum of irreducible operators and semigroups
Proc. Amer. Math. Soc., 150 (1) :257--266
20224900.
Zoller, Julian; Zargaran, Amin; Braschke, Kamil; Meyer, Jörg; Janoske, Uwe; Dittler, Achim
A Novel Apparatus for Simultaneous Laser-Light-Sheet Optical Particle Counting and Video Recording in the Same Measurement Chamber at High Temperature
Sensors, 22 (4)
2022
ISSN: 1424-82204899.
Ehrhardt, Matthias
A physics-informed neural network to model COVID-19 infection and hospitalization scenarios
Advances in continuous and discrete models, 2022 (1) :1–27
2022
Herausgeber: Springer Science and Business Media Deutschland GmbH4898.
Ehrhardt, Matthias
A physics-informed neural network to model COVID-19 infection and hospitalization scenarios
Advances in continuous and discrete models, 2022 (1) :1–27
2022
Herausgeber: Springer Science and Business Media Deutschland GmbH4897.
Ehrhardt, Matthias
A physics-informed neural network to model COVID-19 infection and hospitalization scenarios
Advances in Continuous and Discrete Models, 2022 (1) :61
2022
Herausgeber: Springer International Publishing Cham4896.
Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A port-Hamiltonian formulation of coupled heat transfer
Mathematical and Computer Modelling of Dynamical Systems, 28 (1) :78–94
2022
Herausgeber: Taylor & Francis4895.
Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A port-Hamiltonian formulation of coupled heat transfer
Mathematical and Computer Modelling of Dynamical Systems, 28 (1) :78–94
2022
Herausgeber: Taylor & Francis4894.
Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A port-Hamiltonian formulation of coupled heat transfer
Mathematical and Computer Modelling of Dynamical Systems, 28 (1) :78–94
2022
Herausgeber: Taylor & Francis4893.
Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A port-Hamiltonian formulation of coupled heat transfer
Mathematical and Computer Modelling of Dynamical Systems, 28 (1) :78--94
2022
Herausgeber: Taylor & Francis4892.
Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A Port-Hamiltonian Formulation of Coupled Heat Transfer
Math. Comput. Model. Dyn. Syst., 28 (1) :78-94
2022