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



2015

3153.

Shcherbakov, Dmitry; Ehrhardt, Matthias; Günther, Michael; Peardon, Michael
Force-gradient nested multirate methods for Hamiltonian systems
Computer Physics Communications, 187 :91–97
2015
Herausgeber: North-Holland

3152.

Shcherbakov, Dmitry; Ehrhardt, Matthias; Günther, Michael; Peardon, Michael
Force-gradient nested multirate methods for Hamiltonian systems
Computer Physics Communications, 187 :91–97
2015
Herausgeber: North-Holland

3151.

Shcherbakov, Dmitry; Ehrhardt, Matthias; Günther, Michael; Peardon, Michael
Force-gradient nested multirate methods for Hamiltonian systems
Computer Physics Communications, 187 :91–97
2015
Herausgeber: North-Holland

3150.

Gibilisco, Rodrigo G.; Bejan, Iustinian; Barnes, Ian; Wiesen, Peter; Teruel, Mariano A.
FTIR gas kinetic study of the reactions of ozone with a series of hexenols at atmospheric pressure and 298 K
Chemical Physics Letters, 618 :114-118
2015
Herausgeber: North-Holland

3149.

Gibilisco, Rodrigo G.; Bejan, Iustinian; Barnes, Ian; Wiesen, Peter; Teruel, Mariano A.
FTIR gas kinetic study of the reactions of ozone with a series of hexenols at atmospheric pressure and 298 K
Chemical Physics Letters, 618 :114-118
2015
Herausgeber: North-Holland

3148.

Gibilisco, Rodrigo G.; Bejan, Iustinian; Barnes, Ian; Wiesen, Peter; Teruel, Mariano A.
FTIR gas kinetic study of the reactions of ozone with a series of hexenols at atmospheric pressure and 298 K
Chemical Physics Letters, 618 :114-118
2015
Herausgeber: North-Holland

3147.

Siemon, Dominik; Eckardt, Linda; Robra-Bissantz, Susanne
GamEducation - Spielelemente in der Universitätslehre
HMD - Praxis der Wirtschaftsinformatik, 52 (6) :915-925
2015

3146.

Eckardt, Linda; Huttner, Jan-Paul; Robra-Bissantz, Susanne
GamEducation in einer virtuellen 3D-Umgebung mit Googles Virtual-Reality-Brille Cardboard
Seite 1295-1306
INFORMATIK 2015
Cottbus
Herausgeber: GI-Edition Lecture Notes in Informatics (LNI)
2015

ISBN: 978-3-88579-640-4

3145.

Meuter, Nico
Gefährdungsbeurteilungen zu CHEMIE 2000+ Qualifikationsphase
In Michael W. Tausch and M. von Wachtendonk, Editor
Herausgeber: C. C. Buchner, Bamberg
2015

3144.

Erhardt, Hellmuth; Häring, Andreas P.; Kotthaus, Andreas; Roggel, Markus; Tong, My Linh; Biallas, Phillip; Jübermann, Martin; Mohr, Fabian; Kirsch, Stefan F.
Geminal Diazides Derived from 1,3-Dicarbonyls: A Protocol for Synthesis
The Journal of Organic Chemistry, 80 (24) :12460–12469
2015
ISSN: 0022-3263

3143.

Bolten, Matthias; Donatelli, M.; Huckle, T.; Kravvaritis, C.
Generalized grid transfer operators for multigrid methods applied on Toeplitz matrices
BIT, 55 :341-366
2015

3142.

Bolten, M.; Donatelli, M.; Huckle, T.; Kravvaritis, C.
Generalized grid transfer operators for multigrid methods applied on Toeplitz matrices
BIT, 55 :341-366
2015

3141.

Bolten, M.; Donatelli, M.; Huckle, T.; Kravvaritis, C.
Generalized grid transfer operators for multigrid methods applied on Toeplitz matrices
BIT, 55 :341--366
2015

3140.

Häring, Andreas P.; Klahn, Philipp; Jübermann, Martin; Mohr, Fabian; Kirsch, Stefan F.
Gold(I)-catalyzed heterocyclization of β-alkynyl hydroxamic acids: synthesis of isoxazolidin-3-ones
Monatshefte für Chemie - Chemical Monthly, 146 (1) :119–134
2015
ISSN: 1434-4475

3139.

Hendricks, Christian; Ehrhardt, Matthias
High order combination technique for the efficient pricing of basket options
Acta Mathematica Universitatis Comenianae, 84 (2) :243--253
2015

3138.

Hendricks, Christian; Ehrhardt, Matthias; Günther, Michael
High order combination technique for the efficient pricing of basket options
Acta Mathematica Universitatis Comenianae, 84 (2) :243–253
2015
Herausgeber: Univerzita Komenskeho

3137.

Hendricks, Christian; Ehrhardt, Matthias; Günther, Michael
High order combination technique for the efficient pricing of basket options
Acta Mathematica Universitatis Comenianae, 84 (2) :243–253
2015
Herausgeber: Univerzita Komenskeho

3136.

Hendricks, Christian; Ehrhardt, Matthias; Günther, Michael
High order combination technique for the efficient pricing of basket options
Acta Mathematica Universitatis Comenianae, 84 (2) :243–253
2015
Herausgeber: Univerzita Komenskeho

3135.

Hendricks, Christian; Heuer, Christof; Ehrhardt, Matthias; Günther, Michael
High-order ADI schemes for parabolic equations in the combination technique with application in finance
2015

3134.

Hendricks, Christian; Ehrhardt, Matthias; Günther, Michael
High-Order-Compact ADI schemes for diffusion equations with mixed derivatives in the combination technique
2015

3133.

Hendricks, Christian; Ehrhardt, Matthias; Günther, Michael
High-order-compact ADI schemes for diffusion equations with mixed derivatives in the combination technique
Preprint IMACM
2015
Herausgeber: Bergische Universität Wuppertal

3132.

Hendricks, Christian; Ehrhardt, Matthias; Günther, Michael
High-order-compact ADI schemes for diffusion equations with mixed derivatives in the combination technique
Preprint IMACM
2015
Herausgeber: Bergische Universität Wuppertal

3131.

Hendricks, Christian; Ehrhardt, Matthias; Günther, Michael
High-order-compact ADI schemes for diffusion equations with mixed derivatives in the combination technique
Preprint IMACM
2015
Herausgeber: Bergische Universität Wuppertal

3130.

Alì, Giuseppe; Bartel, Andreas; Rotundo, Nella
Index-2 elliptic partial differential-algebraic models for circuits and devices
Journal of Mathematical Analysis and Applications, 423 (2) :1348–1369
2015
Herausgeber: Academic Press

3129.

Al{\`\i}, Giuseppe; Bartel, Andreas; Rotundo, Nella
Index-2 elliptic partial differential-algebraic models for circuits and devices
Journal of Mathematical Analysis and Applications, 423 (2) :1348--1369
2015
Herausgeber: Academic Press