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

4766.

Bartel, Andreas; Günther, Michael
Multirate Schemes -- An Answer of Numerical Analysis to a Demand from Applications
In Michael Günther and Wil Schilders, Editor, Novel Mathematics Inspired by Industrial Challenges
Seite 5--27
Herausgeber: Springer
2022
5--27

4765.

Bartel, Andreas; Günther, Michael
Multirate schemes—an answer of numerical analysis to a demand from applications
In Günther, Michael and Schilders, Wil, Editor aus Mathematics in Industry
Seite 5–27
Herausgeber: Springer Cham
2022
5–27

4764.

Bartel, Andreas; Günther, Michael
Multirate schemes—an answer of numerical analysis to a demand from applications
Novel Mathematics Inspired by Industrial Challenges
Seite 5--27
Herausgeber: Springer International Publishing Cham
2022
5--27

4763.

Bartel, Andreas; Günther, Michael
Multirate schemes—an answer of numerical analysis to a demand from applications
In Günther, Michael and Schilders, Wil, Editor aus Mathematics in Industry
Seite 5–27
Herausgeber: Springer Cham
2022
5–27

4762.

Kapllani, Lorenc; Teng, Long
Multistep schemes for solving backward stochastic differential equations on {GPU}
JMI, 12 (5)
2022

4761.

Kapllani, Lorenc; Teng, Long
Multistep schemes for solving backward stochastic differential equations on GPU
Journal of Mathematics in Industry, 12 (1) :1–22
2022
Herausgeber: Springer Verlag

4760.

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

4759.

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

4758.

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

4757.

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

4756.

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

4755.

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

4754.

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

4753.

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

4752.

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

4751.

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

4750.

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

4749.

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

4748.

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

4747.

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

4746.

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

4745.

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

4744.

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

4743.

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

4742.

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