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
4792.
Bolten, M.; De Sturler, E.; Hahn, C.
Krylov Subspace Recycling for Evolving Structures
Comput. Methods Appl. Mech. Engrg., 391 :114222
20224791.
Frommer, Andreas; Kahl, Karsten; Schweitzer, Marcel; Tsolakis, Manuel
Krylov subspace restarting for matrix Laplace transforms
20224790.
Krutz, Isabel; Zeller, Diana; Bohrmann-Linde, Claudia
Kursbuch Was brennt bei einer Kerze?. Eine Lerneinheit des Konzepts KriViNat
Herausgeber: Chemiedidaktik. Bergische Universität Wuppertal
2022
online4789.
Kaiser, Jennifer; Zeller, Diana; Bohrmann-Linde, Claudia
Kursbuch zum Brausetablettenversuch. Eine Lerneinheit des Konzepts KriViNat
Herausgeber: Chemiedidaktik, Bergische Universität Wuppertal
2022
online4788.
Bartel, Andreas; Ehrhardt, Matthias
Lagrangian instabilities in thermal convection with
20224787.
Bartel, Andreas; Ehrhardt, Matthias
Lagrangian instabilities in thermal convection with stable temperature profiles
Preprint IMACM
2022
Herausgeber: Bergische Universität Wuppertal4786.
Bartel, Andreas; Ehrhardt, Matthias
Lagrangian instabilities in thermal convection with stable temperature profiles
Preprint IMACM
2022
Herausgeber: Bergische Universität Wuppertal4785.
Bartel, Andreas; Ehrhardt, Matthias
Lagrangian instabilities in thermal convection with stable temperature profiles
arXiv preprint arXiv:2205.03856
April 20224784.
Bartel, Andreas; Ehrhardt, Matthias
Large-scale convective flow sustained by thermally active {L}agrangian tracers
Journal of Fluid Mechanics, 953 :A5
2022
Herausgeber: Cambridge University Press4783.
Bartel, Andreas; Ehrhardt, Matthias
Large-scale convective flow sustained by thermally active Lagrangian tracers
Journal of Fluid Mechanics, 953 :A5
2022
Herausgeber: Cambridge University Press4782.
Bartel, Andreas; Ehrhardt, Matthias
Large-scale convective flow sustained by thermally active Lagrangian tracers
Journal of Fluid Mechanics, 953 :A5
2022
Herausgeber: Cambridge University Press4781.
Bartel, Andreas; Ehrhardt, Matthias
Large-scale convective flow sustained by thermally active Lagrangian tracers
Journal of Fluid Mechanics, 953 :A5
2022
Herausgeber: Cambridge University Press4780.
[german] Tausch, Michael W.
LED statt Gasbrenner - Mehr Licht für nachhaltigen Chemieunterricht
Chemie in unserer Zeit, 56 (3/2022) :188–196
20224779.
Daners, Daniel; Glück, Jochen; Mui, Jonathan
Local uniform convergence and eventual positivity of solutions to biharmonic heat equations
Differential and Integral Equations, 9/10 :727-756
20224778.
others
Manakov system on metric graphs: Modeling the reflectionless propagation of vector solitons in networks
arXiv preprint arXiv:2206.01283, 479 :128928
Mai 2022
ISSN: 0375-96014777.
Bannenberg, Marcus WFM; Kasolis, Fotios; Günther, Michael; Clemens, Markus
Maximum entropy snapshot sampling for reduced basis modelling
COMPEL-The international journal for computation and mathematics in electrical and electronic engineering, 41 (3) :954–966
2022
Herausgeber: Emerald Publishing4776.
Bannenberg, Marcus WFM; Kasolis, Fotios; Günther, Michael; Clemens, Markus
Maximum entropy snapshot sampling for reduced basis modelling
COMPEL-The international journal for computation and mathematics in electrical and electronic engineering, 41 (3) :954–966
2022
Herausgeber: Emerald Publishing4775.
Wahdan, Shayma
Measurements of observables sensitive to colour reconnection in $t\bar{t}$ events with the ATLAS detector at $\sqrt{s}$ = 13 TeV
Bergische Universitaet Wuppertal
20224774.
Jäschke, J.; Skrepek, N.; Ehrhardt, M.
Mixed-Dimensional Geometric Coupling of Port-{Hamiltonian} Systems
IMACM preprint 22/04
Februar 20224773.
Doganay, Onur Tanil; Klamroth, Kathrin; Lang, Bruno; Stiglmayr, Michael; Totzeck, Claudia
Modeling Minimum Cost Network Flows With Port-Hamiltonian Systems
PAMM
2022
Herausgeber: Wiley4772.
Tordeux, Antoine; Totzeck, Claudia
Multi-scale description of pedestrian collective dynamics with port-Hamiltonian systems
20224771.
Hutzenthaler, Martin; Kruse, Thomas; Nguyen, Tuan Anh
Multilevel Picard approximations for McKean-Vlasov stochastic differential equations
Journal of Mathematical Analysis and Applications, 507 (1) :125761
2022
Herausgeber: Academic Press4770.
Hutzenthaler, Martin; Kruse, Thomas; Nguyen, Tuan Anh
Multilevel Picard approximations for McKean-Vlasov stochastic differential equations
Journal of Mathematical Analysis and Applications, 507 (1) :125761
2022
Herausgeber: Academic Press4769.
Hutzenthaler, Martin; Kruse, Thomas; Nguyen, Tuan Anh
Multilevel Picard approximations for McKean-Vlasov stochastic differential equations
Journal of Mathematical Analysis and Applications, 507 (1) :125761
2022
Herausgeber: Academic Press4768.
Günther, Michael; Sandu, Adrian
Multirate linearly-implicit GARK schemes
BIT Numerical Mathematics :869–901
2022
Herausgeber: Springer Netherlands