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



2024

4927.

Vinod, Vivin; Kleinekathöfer, Ulrich; Zaspel, Peter
Optimized multifidelity machine learning for quantum chemistry
Mach. Learn.: Sci. Technol., 5 (1) :015054
2024

4926.

Bolten, Matthias; Doganay, Onur Tanil; Gottschalk, Hanno; Klamroth, Kathrin
Non-convex shape optimization by dissipative {H}amiltonian flows
Engineering Optimization
2024

4925.

Frommer, Andreas; Rinelli, Michele; Schweitzer, Marcel
Analysis of stochastic probing methods for estimating the trace of functions of sparse symmetric matrices
Math. Comp.
2024

4924.

Bauß, Julius; Stiglmayr, Michael
Adapting Branching and Queuing for Multi-objective Branch and Bound
Operations Research Proceedings 2023
Herausgeber: Springer
2024

4923.

Gaul, Daniela; Klamroth, Kathrin; Pfeiffer, Christian; Stiglmayr, Michael; Schulz, Arne
A Tight Formulation for the Dial-a-Ride Problem
European Journal of Operational Research
September 2024
Herausgeber: Elsevier BV
ISSN: 0377-2217

4922.

Bolten, Matthias; Kilmer, Misha E.; MacLachlan, Scott
Multigrid preconditioning for regularized least-squares problems
SIAM J. Sci. Comput., 46 (5) :s271—s295
2024
ISSN: 1064-8275

4921.

Schultes, Johanna
Multiobjective optimization of shapes using scalarization techniques
Dissertation
Dissertation
Bergische Universität Wuppertal
2024

4920.

Allmendinger, Richard; Fonseca, Carlos M.; Sayin, Serpil; Wiecek, Margaret M.; Stiglmayr, Michael
Multiobjective Optimization on a Budget (Dagstuhl Seminar 23361)
2024
Herausgeber: Schloss Dagstuhl – Leibniz-Zentrum für Informatik

4919.

Bolten, M.; Doganay, O. T.; Gottschalk, H.; Klamroth, K.
Non-convex shape optimization by dissipative Hamiltonian flows
Eng. Optim. :1—20
2024

4918.

Dächert, Kerstin; Fleuren, Tino; Klamroth, Kathrin
A simple, efficient and versatile objective space algorithm for multiobjective integer programming
Mathematical Methods of Operations Research
2024

4917.

Hoang, Manh Tuan; Ehrhardt, Matthias
A second-order nonstandard finite difference method for a general Rosenzweig-MacArthur predator--prey model
Journal of Computational and Applied Mathematics :115752
2024
Herausgeber: Elsevier

4916.

Bauß, Julius
On improvements of multi-objective branch and bound
Dissertation
Dissertation
Bergische Universität Wuppertal
2024

4915.

Abel, Ulrich; Acu, Ana Maria; Heilmann, Margareta; Raşa, Ioan
On some Cauchy problems and positive linear operators
2024

4914.

Clemens, Markus; Henkel, Marvin-Lucas; Kasolis, Fotios; Günther, Michael
A Port-Hamiltonian System Perspective on Electromagneto-Quasistatic Field Formulations of Darwin-Type
Preprint
2024

4913.

Lorenz, Jan; Zwerschke, Tom; Guenther, Michael; Schaefers, Kevin
Operator splitting for coupled linear port-Hamiltonian systems
2024

4912.

Kruse, Thomas; Strack, Philipp
Optimal dynamic control of an epidemic
Operations Research, 72 (3) :1031–1048
2024
Herausgeber: INFORMS
2023

4911.

Haussmann, N.; Stroka, S.; Mazaheri, S.; Clemens, M.
Using Point Clouds for Material Properties Smoothing in Low-Frequency Numerical Dosimetry Simulations
21st Biennial IEEE Conference on Electromagnetic Field Computation (CEFC 2024)
Jeju, South Korea
Dezember 2023

4910.

Kähne, B.; Clemens, M.
A GPU Accelerated Semi-Implicit Method for Large-Scale Nonlinear Eddy-Current Problems Using Adaptive Time Step Control
21st Biennial IEEE Conference on Electromagnetic Field Computation (CEFC 2024)
Jeju, South Korea
Dezember 2023

4909.

Abel, Ulrich; Acu, Ana Maria; Heilmann, Margareta; Raşa, Ioan
Voronovskaja formula for Aldaz–Kounchev–Render operators: uniform convergence
Analysis and Mathematical Physics, 14 (1)
Dezember 2023
ISSN: 1664-235X

4908.

Gernandt, Hannes; Hinsen, Dorothea; Cherifi, Karim
The difference between port-Hamiltonian, passive and positive real descriptor systems
Mathematics of Control, Signals, and Systems
Dezember 2023

4907.

Stroka, S.; Kasolis, F.; Haussmann, N.; Clemens, M.
Efficient Low-Frequency Human Exposure Assessment with the Maximum Entropy Snapshot Sampling
21st Biennial IEEE Conference on Electromagnetic Field Computation (CEFC 2024)
Jeju, Korea
November 2023

4906.

Xuan, Mingjun; Fan, Jilin; Khiêm, Vu Ngoc; Zou, Miancheng; Brenske, Kai-Oliver; Mourran, Ahmed; Vinokur, Rostislav; Zheng, Lifei; Itskov, Mikhail; Göstl, Robert; Herrmann, Andreas
Polymer Mechanochemistry in Microbubbles
Advanced Materials, 35 (47) :2305130
November 2023
ISSN: 1521-4095

4905.

Stroka, S.; Haussmann, N.; Clemens, M.
Efficient Assessment of High-Resolution Low-Frequency Magnetic Field Exposure Scenarios Using Reduced Order Models
15th Scientific Computing in Electrical Engineering (SCEE 2024)
Darmstadt, Germany
November 2023

4904.

[german] Grandrath, Rebecca
Videoschnitt für Einsteiger:innen
Unterricht Biologie - Das Schülerarbeitsheft, 51 :32-36
November 2023

4903.

[german] Kiesling, Elisabeth; Kremer, Richard; Pereira Vaz, Nuno; Venzlaff, Julian; Bohrmann-Linde, Claudia
Wege aus der Klimakrise – ein BNE-Schülerlaborangebot mit mehrdimensionalem Zugang
MNU Journal, 76 (06/2023) :464 - 471
November 2023
ISSN: 0025-5866

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