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



2021

4616.

Hahne, J.; Friedhoff, S.; Bolten, Matthias
Algorithm 1016: PyMGRIT: a Python package for the parallel-in-time method MGRIT
ACM Trans. Math. Software, 47 (2) :Art. 19, 22
2021

4615.

Hahne, J.; Friedhoff, S.; Bolten, M.
Algorithm 1016: PyMGRIT: a Python package for the parallel-in-time method MGRIT
ACM Trans. Math. Software, 47 (2) :Art. 19, 22
2021

4614.

Clevenhaus, Anna; Ehrhardt, Matthias; Günther, Michael
An ADI Sparse Grid method for pricing efficiently American options under the Heston model
Advances in Applied Mathematics and Mechanics, 13 (6) :1384–1397
2021
Herausgeber: Global Science Press

4613.

Clevenhaus, Anna; Ehrhardt, Matthias; Günther, Michael
An ADI Sparse Grid method for pricing efficiently American options under the Heston model
Advances in Applied Mathematics and Mechanics, 13 (6) :1384–1397
2021
Herausgeber: Global Science Press

4612.

Clevenhaus, Anna; Ehrhardt, Matthias; Günther, Michael
An ADI Sparse Grid method for pricing efficiently American options under the Heston model
Advances in Applied Mathematics and Mechanics, 13 (6) :1384–1397
2021
Herausgeber: Global Science Press

4611.


An ADI Sparse Grid method for Pricing Efficiently American Options under the Heston Model
ADVANCES IN APPLIED MATHEMATICS AND MECHANICS, 13 (6) :1384--1397
2021
Herausgeber: GLOBAL SCIENCE PRESS Office B, 9/F, Kings Wing Plaza2, No. 1 On Kwan St~…
ISSN: 2075-1354

4610.

Treibert, Sarah; Ehrhardt, Matthias
An Unsupervised Physics-Informed Neural Network to Model COVID-19 Infection and Hospitalization Scenarios
2021

4609.

Frommer, Andreas; Schimmel, Claudia; Schweitzer, Marcel
Analysis of probing techniques for sparse approximation and trace estimation of decaying matrix functions
SIAM J. Matrix Anal. Appl., 42 (3) :1290-1318
2021

4608.

Frommer, Andreas; Schimmel, Claudia; Schweitzer, Marcel
Analysis of probing techniques for sparse approximation and trace estimation of decaying matrix functions
SIAM J. Matrix Anal. Appl., 42 (3) :1290-1318
2021

4607.

Frommer, Andreas; Schimmel, Claudia; Schweitzer, Marcel
Analysis of probing techniques for sparse approximation and trace estimation of decaying matrix functions
SIAM J. Matrix Anal. Appl., 42 (3) :1290-1318
2021

4606.

Braschke, Kamil; Zoller, Julian; Zargaran, Amin; Dittler, Achim; Janoske, Uwe
Analytical and numerical calculation of the detachment of particle structures from fibers
Aerosol Science and Technology :1--11
September 2021
Herausgeber: Informa {UK} Limited

4605.

Muniz, Michelle; Ehrhardt, Matthias; Günther, Michael
Approximating correlation matrices using stochastic Lie group methods
Mathematics, 9 (1) :94
2021
Herausgeber: MDPI

4604.

Muniz, Michelle; Ehrhardt, Matthias; Günther, Michael
Approximating correlation matrices using stochastic Lie group methods
Mathematics, 9 (1) :94
2021
Herausgeber: MDPI

4603.

Muniz, Michelle; Ehrhardt, Matthias; Günther, Michael
Approximating correlation matrices using stochastic Lie group methods
Mathematics, 9 (1) :94
2021
Herausgeber: MDPI

4602.

Muniz, Michelle; Ehrhardt, Matthias; Günther, Michael
Approximating Correlation Matrices Using Stochastic Lie Group Methods
Mathematics, 9 (1) :94
Januar 2021
Herausgeber: MDPI AG
ISSN: 2227-7390

4601.

[english] Kremer, Richard; Bohrmann-Linde, Claudia; Tausch, Michael W.
Artificial Photosynthesis in Chemical Education - Photocatalytic Generation of Hydrogen in Classroom Experiments
Education Quimica, 32 (3)
2021

4600.

Ferrari, Paola; Serra-Capizzano, Stefano
Asymptotic spectra of large matrices coming from the symmetrization of Toeplitz structure functions and applications to preconditioning
Numer. Linear Algebra Appl., 28 (1) :Paper No. e2332, 16
2021

4599.

Ferrari, Paola; Serra-Capizzano, Stefano
Asymptotic spectra of large matrices coming from the symmetrization of Toeplitz structure functions and applications to preconditioning
Numer. Linear Algebra Appl., 28 (1) :Paper No. e2332, 16
2021

4598.

Hahne, J.; Southworth, B. S.; Friedhoff, S.
Asynchronous Truncated Multigrid-reduction-in-time (AT-MGRIT)
2021

4597.

Hahne, J.; Southworth, B. S.; Friedhoff, S.
Asynchronous Truncated Multigrid-reduction-in-time (AT-MGRIT)
2021

4596.

Hahne, J.; Southworth, B. S.; Friedhoff, S.
Asynchronous Truncated Multigrid-reduction-in-time (AT-MGRIT)
2021

4595.

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 the Foot and the Summit of Mt. Tai – Part I: HONO Formation and Its Role in the Oxidizing Capacity of the Upper Boundary Layer
aus preprint
Gases/Field Measurements/Troposphere/Chemistry (chemical composition and reactions)
Juli 2021

4594.

Illmann, Niklas; Gibilisco, Rodrigo Gastón; Bejan, Iustinian Gabriel; Patroescu-Klotz, Iulia; Wiesen, Peter
Atmospheric oxidation of α,β-unsaturated ketones: kinetics and mechanism of the OH radical reaction
Atmospheric Chemistry and Physics, 21 (17) :13667--13686
September 2021
ISSN: 1680-7324

4593.

Illmann, Niklas; Gibilisco, Rodrigo Gastón; Bejan, Iustinian Gabriel; Patroescu-Klotz, Iulia; Wiesen, Peter
Atmospheric oxidation of α,β-unsaturated ketones: kinetics and mechanism of the OH radical reaction
Atmospheric Chemistry and Physics, 21 (17) :13667--13686
September 2021
ISSN: 1680-7324

4592.

Haussmann, N.; Zang, M.; Clemens, M.; B., Schmülling
Bestimmung der Exposition des menschlichen Körpers durch niederfrequente Magnetfelder in der Umgebung induktiv geladener Elektrotaxis – ein Überblick am Beispiel des TALAKO-Projekts
Abstract at URSI e.V. Deutschland 2020 Kleinheubacher Tagung (KHB 2021)
September 2021