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

4866.

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

4865.

Xue, Chaoyang; Ye, Can; Kleffmann, Jörg; Zhang, Chenglong; Catoire, Valéry; Bao, Fengxia; Mellouki, Abdelwahid; Xue, Likun; Chen, Jianmin; Lu, Keding; Zhao, Yong; Liu, Hengde; Guo, Zhaoxin; Mu, Yujing
Atmospheric measurements at Mt. Tai – Part I: HONO formation and its role in the oxidizing capacity of the upper boundary layer
Atmospheric Chemistry and Physics, 22 (5) :3149—3167
März 2022
ISSN: 1680-7324

4864.

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

4863.

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

4862.

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

4861.

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

4860.

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

4859.

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

4858.

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

4857.

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

4856.

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

4855.

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

4854.

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

4853.

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

4852.

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

4851.

Stiglmayr, Michael; Figueira, Jos\'{e} Rui; Klamroth, Kathrin; Paquete, Lu\'{i}s; Schulze, Britta
Decision Space Robustness for Multiobjective Integer Linear Programming
Annals of Operations Research, 319 :1769--1791
2022

4850.

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

4849.


Development of a gas chromatography-mass spectrometry (GC-MS) method for the analysis of triterpenic acids
Lebensmittelchemie, 76 :S2-338-S2-338
2022
Herausgeber: Wiley
ISSN: 0937-1478

4848.

[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

4847.

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

4846.

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

4845.

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

4844.

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

4843.

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

4842.

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