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



2022

4793.

Fatoorehchi, Hooman; Ehrhardt, Matthias
Numerical and semi-numerical solutions of a modified Thévenin model for calculating terminal voltage of battery cells
Journal of Energy Storage, 45 :103746
2022
Herausgeber: Elsevier

4792.

Gerlach, Moritz; Glück, Jochen
On characteristics of the range of integral operators
2022

4791.

Ehrhardt, Matthias
On decomposition of the fundamental solution of the Helmholtz equation over solutions of iterative parabolic equations
Asymptotic Analysis, 126 (3-4) :215–228
2022
Herausgeber: IOS Press

4790.

Ehrhardt, Matthias
On decomposition of the fundamental solution of the Helmholtz equation over solutions of iterative parabolic equations
Asymptotic Analysis, 126 (3-4) :215–228
2022
Herausgeber: IOS Press

4789.

Ehrhardt, Matthias
On decomposition of the fundamental solution of the Helmholtz equation over solutions of iterative parabolic equations
Asymptotic Analysis, 126 (3-4) :215--228
2022
Herausgeber: IOS Press

4788.

Farkas, Bálint; Nagy, Béla; Révész, Szilárd Gy.
On intertwining of maxima of sum of translates functions with nonsingular kernels
Trudy Inst. Mat. Mekh. UrO RAN
2022

4787.

Jacob, Birgit; Morris, Kirsten
On solvability of dissipative partial differential-algebraic equations
IEEE Control. Syst. Lett., 6 :3188-3193
2022

4786.

Petrov, {Pavel S.}; Ehrhardt, Matthias; Trofimov, {M. Yu.}
On the decomposition of the fundamental solution of the {Helmholtz} equation via solutions of iterative parabolic equations
Asymptotic Analysis, 126 (3-4) :215--228
2022
Herausgeber: IOS Press

4785.

Hutzenthaler, Martin; Kruse, Thomas; Nguyen, Tuan Anh
On the speed of convergence of Picard iterations of BSDEs
Probability, Uncertainty and Quantitative Risk, 7 (2)
2022
Herausgeber: American Institute of Mathematical Sciences

4784.

Hutzenthaler, Martin; Kruse, Thomas; Nguyen, Tuan Anh
On the speed of convergence of Picard iterations of BSDEs
Probability, Uncertainty and Quantitative Risk, 7 (2)
2022
Herausgeber: American Institute of Mathematical Sciences

4783.

Hutzenthaler, Martin; Kruse, Thomas; Nguyen, Tuan Anh
On the speed of convergence of Picard iterations of BSDEs
Probability, Uncertainty and Quantitative Risk, 7 (2)
2022
Herausgeber: American Institute of Mathematical Sciences

4782.

Bartel, Andreas; Günther, Michael; Jacob, Birgit; Reis, Timo
Operator Splitting Based Dynamic Iteration for Linear Port-{H}amiltonian Systems
arXiv preprint arXiv:2208.03574
2022

4781.

Bartel, Andreas; Günther, Michael; Jacob, Birgit; Reis, Timo
Operator Splitting Based Dynamic Iteration for Linear Port-Hamiltonian Systems
arXiv preprint arXiv:2208.03574
2022

4780.

Sudhoff, Julia
Ordinal costs in multi-objective combinatorial optimization
Dissertation
Dissertation
Bergische Universität Wuppertal
2022

4779.

[german] Banerji, Amitabh; Dörschelln, Jennifer; Schwarz, D.
Organische Leuchtdioden im Chemieunterricht
Chemie in unserer Zeit, 52 (1) :34-41
2022

4778.

Hutzenthaler, Martin; Jentzen, Arnulf; Kruse, Thomas; Nguyen, Tuan Anh
Overcoming the curse of dimensionality in the numerical approximation of backward stochastic differential equations
Journal of Numerical Mathematics
2022
Herausgeber: De Gruyter

4777.

Hutzenthaler, Martin; Jentzen, Arnulf; Kruse, Thomas
Overcoming the curse of dimensionality in the numerical approximation of parabolic partial differential equations with gradient-dependent nonlinearities
Foundations of Computational Mathematics, 22 (4) :905–966
2022
Herausgeber: Springer New York

4776.

Hutzenthaler, Martin; Jentzen, Arnulf; Kruse, Thomas
Overcoming the curse of dimensionality in the numerical approximation of parabolic partial differential equations with gradient-dependent nonlinearities
Foundations of Computational Mathematics, 22 (4) :905--966
2022
Herausgeber: Springer US New York

4775.

Hutzenthaler, Martin; Jentzen, Arnulf; Kruse, Thomas
Overcoming the curse of dimensionality in the numerical approximation of parabolic partial differential equations with gradient-dependent nonlinearities
Foundations of Computational Mathematics, 22 (4) :905–966
2022
Herausgeber: Springer New York

4774.

Zang, Martin; Haussmann, Norman; Mease, Robin; Stroka, Steven; Clemens, Markus; Burkert, Amelie; Popp, Alexander; Schmülling, Benedikt
Personenschutz bei induktivem Laden von Fahrzeugbatterien -- Ansätze zur praktikablen Echtzeitbestimmung der magneto-quasistatischen Körperexposition
In Proff, Heike, Editor
Seite 173--194
Herausgeber: Springer Fachmedien Wiesbaden, Wiesbaden
2022
173--194

4773.

Acu, Ana-Maria; Heilmann, Margareta; Raşa, Ioan; Seserman, Andra
Poisson approximation to the binomial distribution: extensions to the convergence of positive operators
2022

4772.


Progress in Industrial Mathematics at ECMI 2021
In Ehrhardt, Matthias and Günther, Michael, Editor aus Mathematics in Industry
Herausgeber: Springer Cham
2022

ISBN: 978-3-031-11817-3

4771.


Progress in Industrial Mathematics at ECMI 2021
In Ehrhardt, Matthias and Günther, Michael, Editor aus Mathematics in Industry
Herausgeber: Springer Cham
2022

ISBN: 978-3-031-11817-3

4770.


Progress in Industrial Mathematics at ECMI 2021
In Ehrhardt, Matthias and Günther, Michael, Editor aus Mathematics in Industry
Herausgeber: Springer Cham
2022

ISBN: 978-3-031-11817-3

4769.

Ehrhardt, Matthias; Günther, Michael
Progress in Industrial Mathematics at ECMI 2021
2022