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
- 2020
4217.
Arendt, Wolfgang; ter Elst, Antonius F. M.; Glück, Jochen
Strict positivity for the principal eigenfunction of elliptic operators with various boundary conditions
Adv. Nonlinear Stud., 20 (3) :633--650
20204216.
Acu, Ana-Maria; Heilmann, Margareta; Raşa, Ioan
Strong converse results for linking operators and convex functions
Journal of Function Spaces, 2020 (1) :4049167
20204215.
Bunker, P. R.; Jensen, Per
The Planck constant of action h\(_{A}\)
Journal of Quantitative Spectroscopy and Radiative Transfer
20204214.
Bunker, P. R.; Jensen, Per
The Planck constant of action h\(_{A}\)
Journal of Quantitative Spectroscopy and Radiative Transfer
20204213.
Bunker, P. R.; Jensen, Per
The Planck constant of action hA
Journal of Quantitative Spectroscopy and Radiative Transfer
20204212.
Kreidler, Henrik
The primitive spectrum of a semigroup of {M}arkov operators
Positivity, 24 (2) :287--312
20204211.
Kreidler, Henrik
The primitive spectrum of a semigroup of Markov operators
Positivity, 24 (2) :287--312
20204210.
Farkas, Bálint; Kreidler, Henrik
Towards a Koopman theory for dynamical systems on completely regular spaces
Phil. Trans. Royal Soc. A, 378
20204209.
Günther, Christoph; Günther, Michael; Günther, Daniel
Tracing contacts to control the COVID-19 pandemic
Preprint
20204208.
Günther, Christoph; Günther, Michael; Günther, Daniel
Tracing contacts to control the COVID-19 pandemic
arXiv preprint arXiv:2004.00517
20204207.
Günther, Christoph; Günther, Michael; Günther, Daniel
Tracing contacts to control the COVID-19 pandemic
Preprint
20204206.
Transparent boundary conditions for the sine-Gordon equation
20204205.
Ehrhardt, Matthias
Valuation of basket credit default swaps under stochastic default intensity models
Advances in Applied Mathematics and Mechanics, 12 (5) :1301–1326
2020
Herausgeber: Global Science Press4204.
Ehrhardt, Matthias
Valuation of basket credit default swaps under stochastic default intensity models
Advances in Applied Mathematics and Mechanics, 12 (5) :1301–1326
2020
Herausgeber: Global Science Press4203.
Ehrhardt, Matthias
Valuation of basket credit default swaps under stochastic default intensity models
Advances in Applied Mathematics and Mechanics, 12 (5) :1301--1326
2020
Herausgeber: Global Science Press4202.
Tausch, Michael W.
Videoclip oder Realexperiment?
Nachrichten aus der Chemie, 68 (6-7) :18-19
20204201.
Skrepek, Nathanael
Well-posedness of linear first order Port-Hamiltonian Systems on multidimensional spatial domains
Evolution Equation \& Control Theory
20204200.
Ehrhardt, Matthias
Wide-angle mode parabolic equations for the modelling of horizontal refraction in underwater acoustics and their numerical solution on unbounded domains
Journal of Sound and Vibration, 484 :115526
2020
Herausgeber: Academic Press4199.
Ehrhardt, Matthias
Wide-angle mode parabolic equations for the modelling of horizontal refraction in underwater acoustics and their numerical solution on unbounded domains
Journal of Sound and Vibration, 484 :115526
2020
Herausgeber: Academic Press4198.
Ehrhardt, Matthias
Wide-angle mode parabolic equations for the modelling of horizontal refraction in underwater acoustics and their numerical solution on unbounded domains
Journal of Sound and Vibration, 484 :115526
2020
Herausgeber: Academic Press- 2019
4197.
Yildiz, Deniz; Baumann, Christoph; Mikosch, Annabel; Kuehne, Alexander J. C.; Herrmann, Andreas; Göstl, Robert
Anti-Stokes Stress Sensing: Mechanochemical Activation of Triplet–Triplet Annihilation Photon Upconversion
Angewandte Chemie International Edition, 58 (37) :12919-12923
September 2019
ISSN: 1521-37734196.
Yildiz, Deniz; Baumann, Christoph; Mikosch, Annabel; Kuehne, Alexander J. C.; Herrmann, Andreas; Göstl, Robert
Anti-Stokes-Belastungsanzeige: Mechanochemische Aktivierung der Triplett-Triplett-Annihilierung-Photonen-Hochkonversion
Angewandte Chemie, 131 (37) :13051-13055
September 2019
ISSN: 1521-37574195.
Jensen, Per
Linear and bent triatomic molecules are not qualitatively different!
Canadian Journal of Physics
August 20194194.
Jensen, Per
Linear and bent triatomic molecules are not qualitatively different!
Canadian Journal of Physics :1-6
August 2019
Herausgeber: NRC Research Press4193.
Jensen, Per
Linear and bent triatomic molecules are not qualitatively different!
Canadian Journal of Physics :1-6
August 2019
Herausgeber: NRC Research Press