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

4491.

Donatelli, Marco; Ferrari, Paola; Furci, Isabella; Serra-Capizzano, Stefano; Sesana, Debora
Multigrid methods for block-Toeplitz linear systems: convergence analysis and applications
Numer. Linear Algebra Appl., 28 (4) :Paper No. e2356, 20
2021

4490.

Donatelli, Marco; Ferrari, Paola; Furci, Isabella; Serra-Capizzano, Stefano; Sesana, Debora
Multigrid methods for block-Toeplitz linear systems: convergence analysis and applications
Numer. Linear Algebra Appl., 28 (4) :Paper No. e2356, 20
2021
ISSN: 1070-5325

4489.

Donatelli, Marco; Ferrari, Paola; Furci, Isabella; Serra-Capizzano, Stefano; Sesana, Debora
Multigrid methods for block-Toeplitz linear systems: convergence analysis and applications
Numer. Linear Algebra Appl., 28 (4) :Paper No. e2356, 20
2021
ISSN: 1070-5325

4488.

Hutzenthaler, Martin; Jentzen, Arnulf; Kruse, Thomas; others
Multilevel Picard iterations for solving smooth semilinear parabolic heat equations
Partial Differential Equations and Applications, 2 (6) :1--31
2021
Herausgeber: Springer

4487.

Hutzenthaler, Martin; Jentzen, Arnulf; Kruse, Thomas; others
Multilevel Picard iterations for solving smooth semilinear parabolic heat equations
Partial Differential Equations and Applications, 2 (6) :1–31
2021
Herausgeber: Springer International Publishing

4486.

Ferrari, Paola; Furci, Isabella; Serra-Capizzano, Stefano
Multilevel symmetrized Toeplitz structures and spectral distribution results for the related matrix sequences
Electron. J. Linear Algebra, 37 :370-386
2021

4485.

Ferrari, Paola; Furci, Isabella; Serra-Capizzano, Stefano
Multilevel symmetrized Toeplitz structures and spectral distribution results for the related matrix sequences
Electron. J. Linear Algebra, 37 :370-386
2021

4484.

Ferrari, Paola; Furci, Isabella; Serra-Capizzano, Stefano
Multilevel symmetrized Toeplitz structures and spectral distribution results for the related matrix sequences
Electron. J. Linear Algebra, 37 :370-386
2021

4483.

Hachtel, Christoph; Bartel, Andreas; Günther, Michael; Sandu, Adrian
Multirate implicit Euler schemes for a class of differential--algebraic equations of index-1
Journal of Computational and Applied Mathematics, 387 :112499
2021
Herausgeber: North-Holland

4482.

Hachtel, Christoph; Bartel, Andreas; Günther, Michael; Sandu, Adrian
Multirate implicit Euler schemes for a class of differential-algebraic equations of index-1
Journal of Computational and Applied Mathematics, 387 :112499
2021
Herausgeber: North-Holland

4481.

Hachtel, Christoph; Bartel, Andreas; Günther, Michael; Sandu, Adrian
Multirate implicit Euler schemes for a class of differential-algebraic equations of index-1
Journal of Computational and Applied Mathematics, 387 :112499
2021
Herausgeber: North-Holland

4480.

Günther, Michael; Sandu, Adrian
Multirate linearly-implicit GARK schemes
BIT Numerical Mathematics :1--33
2021
Herausgeber: Springer Netherlands

4479.

Lübke, Marco
Neuartige multifunktionelle Tenside auf Basis nachwachsender Rohstoffe
2021

4478.

Claus, L.; Bolten, Matthias
Non-overlapping block smoothers for the Stokes equations
Num. Lin. Alg. Appl., 28 (6) :e2389
2021

4477.

Claus, L.; Bolten, M.
Non-overlapping block smoothers for the Stokes equations
Num. Lin. Alg. Appl., 28 (6) :e2389
2021

4476.

Claus, L.; Bolten, M.
Non-overlapping block smoothers for the Stokes equations
Num. Lin. Alg. Appl., 28 (6) :e2389
2021

4475.

Eichfelder, Gabriele; Klamroth, Kathrin; Niebling, Julia
Nonconvex constrained optimization by a filtering branch and bound
Journal of Global Optimization, 80 :31-61
2021

4474.

Mironchenko, Andrii; Kawan, Christoph; Glück, Jochen
Nonlinear small-gain theorems for input-to-state stability of infinite interconnections
Math. Control Signals Systems, 33 (4) :573--615
2021

4473.

Krämer, Veronika; Barwari, Beawer; Burgmann, Sebastian; Rohde, Martin; Rentschler, Simon; Holzknecht, Christopher; Gmelin, Christoph; Janoske, Uwe
Numerical analysis of an adhering droplet applying an adapted feedback deceleration technique
International Journal of Multiphase Flow, 145 :103808
Dezember 2021
Herausgeber: Elsevier {BV}

4472.

Jacob, Birgit; Zwart, Hans
Observability for port-Hamiltonian systems
European Control Conference (ECC) :2052-2057
2021

4471.

Markert, Clara; Thinius, Marco; Lehmann, Laura; Heintz, Chris; Stappert, Florian; Wissdorf, Walter; Kersten, Hendrik; Benter, Thorsten; Schneider, Bradley B.; Covey, Thomas R.
Observation of charged droplets from electrospray ionization (ESI) plumes in API mass spectrometers
Analytical and Bioanalytical Chemistry
Juli 2021
ISSN: 1618-2642, 1618-2650

4470.

Friedhoff, S.; Southworth, B. S.
On "optimal" $h$-independent convergence of parareal and multigrid-reduction-in-time using Runge-Kutta time integration
Numer. Linear Algebra Appl., 28 (3)
2021

4469.

Friedhoff, S.; Southworth, B. S.
On "optimal" $h$-independent convergence of parareal and multigrid-reduction-in-time using Runge-Kutta time integration
Numer. Linear Algebra Appl., 28 (3) :Paper No. e2301, 30
2021

4468.

Friedhoff, S.; Southworth, B. S.
On "optimal" $h$-independent convergence of parareal and multigrid-reduction-in-time using Runge-Kutta time integration
Numer. Linear Algebra Appl., 28 (3) :Paper No. e2301, 30
2021

4467.

Farkas, Bálint; Friesen, Martin; Rüdiger, Barbara; Schroers, Dennis
On a class of stochastic partial differential equations with multiple invariant measures
NoDEA
2021