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
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
- Efficiency of the time-integration for field devices in pulsed circuits (multirate, dynamic iteration)
- DAE-index of the coupled system
- Existence and Uniqueness of the solution
Cooperation
- Herbert De Gersem, Katholieke Universiteit Leuven
- Markus Clemens, Bergische Universität Wuppertal
- Sascha Baumanns, Universität zu Köln
Former and ongoing projects
Publications
- 2022
4716.
Aad, Georges; others
Search for flavour-changing neutral-current interactions of a top quark and a gluon in pp collisions at $\sqrt{s}=13$~TeV with the ATLAS detector
Eur. Phys. J. C, 82 (4) :334
20224715.
Vorländer, Anna
Search for high-mass resonances in dilepton final states with associated b-jets at the ATLAS experiment
20224714.
Austrup, Volker Andreas
Search for scalar and vector leptoquarks decaying into quarks and leptons of different generations
Bergische Universitaet Wuppertal
20224713.
Roggel, Jens
Search for vector-like partners of the top and bottom quarks with the ATLAS experiment
Wuppertal U.
20224712.
Abreu, Pedro; others
Searches for Ultra-High-Energy Photons at the Pierre Auger Observatory
Universe, 8 (11) :579
20224711.
Ackermann, Julia; Kruse, Thomas; Urusov, Mikhail
Self-exciting price impact via negative resilience in stochastic order books
Annals of Operations Research :1--23
2022
Herausgeber: Springer4710.
Kienitz, J.
Semi-Analytic Conditional Expectations
RISK, 7
20224709.
Kienitz, Jörg
Semi-analytical conditional expectations
Risk Cutting Edge, 7
2022
Herausgeber: Incisive Media4708.
Arora, Sahiba; Glück, Jochen
Stability of (eventually) positive semigroups on spaces of continuous functions
C. R., Math., Acad. Sci. Paris, 360 :771--775
20224707.
Gerlach, Moritz; Glück, Jochen; Kunze, Markus
Stability of transition semigroups and applications to parabolic equations
To appear in Trans. Amer. Math. Soc.
20224706.
Muniz, Michelle; Ehrhardt, Matthias; Günther, Michael; Winkler, Renate
Stochastic Runge-Kutta-Munthe-Kaas methods in the modelling of perturbed rigid bodies
Advances in Applied Mathematics and Mechanics, 14 (2) :528–538
2022
Herausgeber: Global Science Press4705.
Muniz, Michelle; Ehrhardt, Matthias; Günther, Michael; Winkler, Renate
Stochastic Runge-Kutta-Munthe-Kaas methods in the modelling of perturbed rigid bodies
Advances in Applied Mathematics and Mechanics, 14 (2) :528–538
2022
Herausgeber: Global Science Press4704.
Muniz, Michelle; Ehrhardt, Matthias; Günther, Michael; Winkler, Renate
Stochastic Runge-Kutta-Munthe-Kaas methods in the modelling of perturbed rigid bodies
Advances in Applied Mathematics and Mechanics, 14 (2) :528–538
2022
Herausgeber: Global Science Press4703.
Muniz, Michelle; Ehrhardt, Matthias; Günther, Michael; Winkler, Renate
Stochastic Runge-Kutta–Munthe-Kaas Methods in the Modelling of Perturbed Rigid Bodies
AAMM, 14 (2) :528--538
2022
ISSN: 2075-13544702.
Kienitz, Jörg
Stochastic volatility – a story of two decades of SABR and Wilmott magazine
Wilmott, 2022 (121) :24–26
2022
Herausgeber: Wilmott Magazine4701.
Muniz, M.; Ehrhardt, M.; Günther, M.; Winkler, R.
Strong stochastic Runge-Kutta-Munthe-Kaas methods for nonlinear Itô SDEs on manifolds
IMACM preprint 22/14
Juni 20224700.
[english] Mertineit, Ann-Kathrin; Schaper, Klaus; Bohrmann-Linde, Claudia; Burdinski, Dirk; Zulauf, Bert; Meuter, Nico; Hackradt, Hans; Kremer, Richard
Teaching Software Skills Using a Freely Accessible Learning Space - an OER Approach
Seite 7073-7081
2022ISBN: 978-84-09-42484-9
4699.
Alvarez, Elena Gómez; Carslaw, Nicola; Dusanter, Sébastien; Edwards, Pete; Gábor Mihucz, Viktor; Heard, Dwayne; Kleffmann, Jörg; Nehr, Sascha; Schoemacker, Coralie; Venables, Dean
Techniques for measuring indoor radicals and radical precursors
Applied Spectroscopy Reviews, 57 (7) :580—624
August 2022
ISSN: 0570-4928, 1520-569X4698.
Kääpä, Alex; Kampert, Karl-Heinz; Mayotte, Eric
The effects of the GMF on the transition from Galactic to extragalactic cosmic rays
PoS, ICRC2021 :004
20224697.
Albrecht, Johannes; others
The Muon Puzzle in cosmic-ray induced air showers and its connection to the Large Hadron Collider
Astrophys. Space Sci., 367 (3) :27
20224696.
Clevenhaus, Anna; Ehrhardt, Matthias; Günther, Michael
The parareal algorithm and the sparse grid combination technique in the application of the Heston model
Progress in Industrial Mathematics at ECMI 2021, Seite 477–483
Herausgeber: Springer Cham
20224695.
Clevenhaus, Anna; Ehrhardt, Matthias; Günther, Michael
The parareal algorithm and the sparse grid combination technique in the application of the Heston model
Progress in Industrial Mathematics at ECMI 2021, Seite 477–483
Herausgeber: Springer Cham
20224694.
Clevenhaus, Anna; Ehrhardt, Matthias; Günther, Michael
The parareal algorithm and the sparse grid combination technique in the application of the Heston model
Progress in Industrial Mathematics at ECMI 2021, Seite 477–483
Herausgeber: Springer Cham
20224693.
Clevenhaus, Anna; Ehrhardt, Matthias; Günther, Michael
The Parareal Algorithm and the Sparse Grid Combination Technique in the Application of the Heston Model
Progress in Industrial Mathematics at ECMI 2021
Seite 477--483
Herausgeber: Springer International Publishing Cham
2022
477--4834692.
Bolten, Matthias; Ekström, S.-E.; Furci, I.; Serra-Capizzano, S.
Toeplitz Momentary Symbols: definition, results, and limitations in the spectral analysis of structured matrices
Linear Algebra Appl., 651 :51-82
2022