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

4918.

Abreu, Pedro; others
A Search for Photons with Energies Above 2 x 10^{17} eV Using Hybrid Data from the Low-Energy Extensions of the Pierre Auger Observatory
Astrophys. J., 933 (2) :125
2022

4917.

Glück, Jochen; Roth, Stefan; Spodarev, Evgeny
A solution to a linear integral equation with an application to statistics of infinitely divisible moving averages
Scand. J. Stat. :30 pages
2022

4916.

Bolten, M.; Donatelli, M.; Ferrari, P.; Furci, I.
A symbol based analysis for multigrid methods for block-circulant and block-Toeplitz Systems
SIAM J. Matrix Anal. Appl., 43 (1) :405-438
2022

4915.

Bolten, Matthias; Donatelli, Marco; Ferrari, Paola; Furci, Isabella
A symbol-based analysis for multigrid methods for block-circulant and block-Toeplitz systems
SIAM J. Matrix Anal. Appl., 43 (1) :405-438
2022
ISSN: 0895-4798

4914.

Bolten, Matthias; Donatelli, Marco; Ferrari, Paola; Furci, Isabella
A symbol-based analysis for multigrid methods for block-circulant and block-Toeplitz systems
SIAM J. Matrix Anal. Appl., 43 (1) :405-438
2022
ISSN: 0895-4798

4913.

Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A two-dimensional port-Hamiltonian model for coupled heat transfer
Mathematics, 10 (24) :4635
2022
Herausgeber: MDPI

4912.

Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A two-dimensional port-Hamiltonian model for coupled heat transfer
Mathematics, 10 (24) :4635
2022
Herausgeber: MDPI

4911.

Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A two-dimensional port-Hamiltonian model for coupled heat transfer
Mathematics, 10 (24) :4635
2022
Herausgeber: MDPI

4910.

Jäschke, Jens; Ehrhardt, M.; Günther, M.; Jacob, Birgit
A Two-Dimensional Port-Hamiltonian Model for Coupled Heat Transfer
Mathematics, 10(24) :4635
2022

4909.

Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A Two-Dimensional Port-Hamiltonian Model for Coupled Heat Transfer
Mathematics, 10 (24) :4635
2022
Herausgeber: MDPI

4908.

Yoda, R.; Bolten, Matthias; Nakajima, K.; Fujii, A.
Acceleration of optimized coarse-grid operators by spatial redistribution for multigrid reduction in time
In Groen, Derek and de Mulatier, Clelia and Paszynski, Maciej and Krzhizhanovskaya, Valeria V. and Dongarra, Jack J. and Sloot, Peter M. A., Editor, Computational Science - ICCS 2022, Seite 214-221
In Groen, Derek and de Mulatier, Clelia and Paszynski, Maciej and Krzhizhanovskaya, Valeria V. and Dongarra, Jack J. and Sloot, Peter M. A., Editor
Herausgeber: Springer International Publishing, Cham
2022

4907.

Yoda, R.; Bolten, M.; Nakajima, K.; Fujii, A.
Acceleration of optimized coarse-grid operators by spatial redistribution for multigrid reduction in time
In Groen, Derek and de Mulatier, Clelia and Paszynski, Maciej and Krzhizhanovskaya, Valeria V. and Dongarra, Jack J. and Sloot, Peter M. A., Editor, Computational Science - ICCS 2022, Seite 214-221
In Groen, Derek and de Mulatier, Clelia and Paszynski, Maciej and Krzhizhanovskaya, Valeria V. and Dongarra, Jack J. and Sloot, Peter M. A., Editor
Herausgeber: Springer International Publishing, Cham
2022

4906.

Ehrhardt, Matthias
An efficient second-order method for the linearized Benjamin-Bona-Mahony equation with artificial boundary conditions
Preprint IMACM
2022
Herausgeber: Bergische Universität Wuppertal

4905.

Ehrhardt, Matthias
An efficient second-order method for the linearized Benjamin-Bona-Mahony equation with artificial boundary conditions
Preprint IMACM
2022
Herausgeber: Bergische Universität Wuppertal

4904.

Ehrhardt, Matthias
An efficient second-order method for the linearized Benjamin-Bona-Mahony equation with artificial boundary conditions
2022

4903.

Arora, Sahiba; Glück, Jochen
An operator theoretic approach to uniform (anti-)maximum principles
J. Differential Equations, 310 :164--197
2022

4902.

Glück, Jochen
Analyticity of positive semigroups is inherited under domination
2022

4901.

Schneider, Lukas; Kaul, Matthias; Braschke, Kamil; Eilts, Peter; Schmidt, Eberhard; Janoske, Uwe
Ash Behaviour in Wall-Flow Filters
In Bargende, Michael and Reuss, Hans-Christian and Wagner, Andreas, Editor, 22. Internationales Stuttgarter Symposium, Seite 629--646
In Bargende, Michael and Reuss, Hans-Christian and Wagner, Andreas, Editor
Herausgeber: Springer Fachmedien Wiesbaden, Wiesbaden
2022

ISBN: 978-3-658-37009-1

4900.

Yoda, R.; Bolten, M.; Nakajima, K.; Fujii, A.
Assignment of idle processors to spatial redistributed domains on coarse levels in multigrid reduction in time
Proceedings of the International Conference on High Performance Computing in Asia-Pacific Region, Seite (accepted)
2022

4899.

Yoda, R.; Bolten, Matthias; Nakajima, K.; Fujii, A.
Assignment of idle processors to spatial redistributed domains on coarse levels in multigrid reduction in time
Proceedings of the International Conference on High Performance Computing in Asia-Pacific Region, Seite 41-51
2022

4898.

Yoda, R.; Bolten, M.; Nakajima, K.; Fujii, A.
Assignment of idle processors to spatial redistributed domains on coarse levels in multigrid reduction in time
Proceedings of the International Conference on High Performance Computing in Asia-Pacific Region, Seite 41-51
2022

4897.

Sch\"afers, Torben; Teng, Long
Asymmetry in stochastic volatility models with threshold and time-dependent correlation
Studies in Nonlinear Dynamics \& Econometrics
2022

4896.

Rottmann, Matthias; Reese, Marco
Automated Detection of Label Errors in Semantic Segmentation Datasets via Deep Learning and Uncertainty Quantification
2022

4895.

Gremmel, Jan N.; Grogorick, Linda; Robra-Bissantz, Susanne; Woisetschläger, David M.
Bildungsangebote als Bindeglied zwischen Forschung und Praxis - Wie aus Forschungsergebnissen zu neuen Technologien praxisrelevante Ideen für Innovationen entstehen
HMD - Praxis der Wirtschaftsinformatik, 60 :230–245
2022

4894.

Forget, Nicolas; Gadegaard, Sune Lauth; Klamroth, Kathrin; Nielsen, Lars Relund; Przybylski, Anthony
Branch-and-bound and objective branching with three or more objectives
Computers & Operations Research, 148
2022
ISSN: 0305-0548