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

4893.

Paquete, Luís; Schulze, Britta; Stiglmayr, Michael; Lourenço, Ana Catarina
Computing Representations using Hypervolume Scalarizations
Computers and Operations Research, 137 :105349
2022

4892.

Muniz, Michelle; Ehrhardt, Matthias; Günther, Michael
Correlation matrices driven by stochastic isospectral flows
Progress in Industrial Mathematics at ECMI 2021, Seite 455–461
Herausgeber: Springer Cham
2022

4891.

Muniz, Michelle; Ehrhardt, Matthias; Günther, Michael
Correlation matrices driven by stochastic isospectral flows
Progress in Industrial Mathematics at ECMI 2021, Seite 455–461
Herausgeber: Springer Cham
2022

4890.

Muniz, Michelle; Ehrhardt, Matthias; Günther, Michael
Correlation matrices driven by stochastic isospectral flows
Progress in Industrial Mathematics at ECMI 2021, Seite 455–461
Herausgeber: Springer Cham
2022

4889.

Muniz, Michelle; Ehrhardt, Matthias; Günther, Michael
Correlation Matrices Driven by Stochastic Isospectral Flows
Progress in Industrial Mathematics at ECMI 2021
Seite 455--461
Herausgeber: Springer International Publishing Cham
2022
455--461

4888.

Arora, Sahiba; Glück, Jochen
Criteria for eventual domination of operator semigroups and resolvents
To appear in the Proceedings of IWOTA 2021, Lancaster
2022

4887.

Anna Braun, geboren Tscherniewski
Crowd Management at Train Stations in Case of Large-Scale Emergency Events
Bergische Universität Wuppertal
2022

4886.

Alves Batista, Rafael; others
CRPropa 3.2 -- an advanced framework for high-energy particle propagation in extragalactic and galactic spaces
JCAP, 09 :035
2022

4885.

Schweitzer, Marcel
Decay bounds for Bernstein functions of Hermitian matrices with applications to the fractional graph Laplacian
Electron. Trans. Numer. Anal., 55 :438-454
2022

4884.

Schweitzer, Marcel
Decay bounds for Bernstein functions of Hermitian matrices with applications to the fractional graph Laplacian
Electron. Trans. Numer. Anal., 55 :438-454
2022

4883.

Schweitzer, Marcel
Decay bounds for Bernstein functions of Hermitian matrices with applications to the fractional graph Laplacian
Electron. Trans. Numer. Anal., 55 :438-454
2022

4882.

Stiglmayr, Michael; Figueira, José Rui; Klamroth, Kathrin; Paquete, Luís; Schulze, Britta
Decision Space Robustness for Multiobjective Integer Linear Programming
Annals of Operations Research, 319 :1769--1791
2022

4881.

Stiglmayr, Michael; Uhlemeyer, Svenja; Uhlemeyer, Björn; Zdrallek, Markus
Determining Cost-Efficient Controls of Electrical Energy Storages Using Dynamic Programming
2022

4880.

[german] Cornelius, Soraya; Bohrmann-Linde, Claudia
Digitalisierung: Mit einem E‐Book in die organische Chemie starten
Nachrichten aus der Chemie, 70 (1) :34-36
2022

4879.

Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
Discrete port-Hamiltonian coupled heat transfer
In Ehrhardt, Matthias and Günther, Michael, Editor, Progress in Industrial Mathematics at ECMI 2021, Seite 439–445
In Ehrhardt, Matthias and Günther, Michael, Editor
Herausgeber: Springer Cham
2022

4878.

Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
Discrete port-Hamiltonian coupled heat transfer
In Ehrhardt, Matthias and Günther, Michael, Editor, Progress in Industrial Mathematics at ECMI 2021, Seite 439–445
In Ehrhardt, Matthias and Günther, Michael, Editor
Herausgeber: Springer Cham
2022

4877.

Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
Discrete port-Hamiltonian coupled heat transfer
In Ehrhardt, Matthias and Günther, Michael, Editor, Progress in Industrial Mathematics at ECMI 2021, Seite 439–445
In Ehrhardt, Matthias and Günther, Michael, Editor
Herausgeber: Springer Cham
2022

4876.

Jäschke, Jens; Ehrhardt, M.; Günther, M.; Jacob, Birgit
Discrete port-Hamiltonian Coupled Heat Transfer
Progress in Industrial Mathematics at ECMI 2021, The European Consortium for Mathematics in Industry, Seite 439-445
In M. Ehrhardt and M. Günther, Editor
Herausgeber: Springer
2022

4875.

Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
Discrete port-Hamiltonian coupled heat transfer
Progress in Industrial Mathematics at ECMI 2021
Seite 439--445
Herausgeber: Springer International Publishing Cham
2022
439--445

4874.

Edeko, Nikolai; Kreidler, Henrik
Distal systems in topological dynamics and ergodic theory
2022

4873.

Lugo, Pedro L.; Straccia, V.G.; Rivela, Cynthia B.; Patroescu-Klotz, Iulia; Illmann, Niklas; Teruel, Mariano A.; Wiesen, Peter; Blanco, María B.
Diurnal photodegradation of fluorinated diketones (FDKs) by OH radicals using different atmospheric simulation chambers: Role of keto-enol tautomerization on reactivity
Chemosphere, 286 :131562
Januar 2022
ISSN: 00456535

4872.

Khosrawi-Rad, Bijan; Grogorick, Linda; Keller, Paul; Schlimbach, Ricarda; Rinn, Heidi; Robra-Bissantz, Susanne
Do you trust the Bot? – Entwicklung und Evaluation eines Conversational Agents zur Klassifikation von Lernstilen
Seite 75-80
20. E-Learning Fachtagung Informatik (DeLFI)
Karlsruhe
2022

ISBN: 978-3-88579-716-6

4871.

Rohde, Martin; Barwari, Beawer; Burgmann, Sebastian; Janoske, Uwe
Droplet motion induced by superposition of shear flow and horizontal surface vibration
International Journal of Multiphase Flow, 155 :104163
2022
Herausgeber: Pergamon

4870.

McWalter, Thomas A; Kienitz, Jörg; Nowaczyk, Nikolai; Rudd, Ralph; Acar, Sarp K.
Dynamic initial margin estimation based on quantiles of Johnson distributions
Journal of Credit Risk, 18 :93–116
2022
Herausgeber: Incisive Media

4869.

Kienitz, Jörg; Lee, Gordon; Nowaczyk, Nikolai; Geng, N.
Dynamically controlled kernel estimation
Risk Cutting Edge, 1
2022
Herausgeber: Incisive Media