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



1998

727.

Shestakov, Oleg; Gielen, R.; Fink, Ewald H.
LIF Studies of the A\verb=~= \(^{1}\)A' States of BiOH and BiOD
Journal of Molecular Spectroscopy, 192 (1) :111-118
1998
Herausgeber: Academic Press

726.

Kleffmann, Jörg; Becker, Karl Heinz; Wiesen, Peter
Investigation of the heterogeneous NO2 conversion on perchloric acid surfaces
Journal of the Chemical Society - Faraday Transactions, 94 (21) :3289-3292
1998
Herausgeber: Royal Society of Chemistry

725.

Kleffmann, J{ö}rg; Becker, Karl Heinz; Wiesen, Peter
Investigation of the heterogeneous NO\(_{2}\) conversion on perchloric acid surfaces
Journal of the Chemical Society - Faraday Transactions, 94 (21) :3289-3292
1998
Herausgeber: Royal Society of Chemistry

724.

Kleffmann, J{ö}rg; Becker, Karl Heinz; Wiesen, Peter
Investigation of the heterogeneous NO\(_{2}\) conversion on perchloric acid surfaces
Journal of the Chemical Society - Faraday Transactions, 94 (21) :3289-3292
1998
Herausgeber: Royal Society of Chemistry

723.

Ziebarth, K.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.
High-resolution study of the X2 2Π3/2 → X1 2Π1/2 fine structure transitions of PbF and PbCl
Journal of Molecular Spectroscopy, 191 (1) :108-116
1998
Herausgeber: Academic Press
1997

722.

Jensen, Per; Sauer, Stephan P. A.
Theoretical calculations of the hyperfine structure in the spectra of H3+ and its deuterated isotopomers
Molecular Physics, 91 (2) :319-332
1997

721.

Jensen, Per
Theoretical Rotation-Vibration Energies of X~3B1 NH2+
Journal of Molecular Spectroscopy, 181 (1) :207-214
1997
Herausgeber: Academic Press

720.

Jensen, Per
Theoretical Rotation-Vibration Energies of X\verb=~=\(^{3}\)B\(_{1}\) NH\(_{2}\)\(^{+}\)
Journal of Molecular Spectroscopy, 181 (1) :207-214
1997
Herausgeber: Academic Press

719.

Jensen, Per
Theoretical Rotation-Vibration Energies of X\verb=~=\(^{3}\)B\(_{1}\) NH\(_{2}\)\(^{+}\)
Journal of Molecular Spectroscopy, 181 (1) :207-214
1997
Herausgeber: Academic Press

718.

Günther, Michael; Feldmann, Uwe
CAD based electric modeling in Industry
1997

717.

Jensen, Per; Sauer, Stephan P. A.
Theoretical calculations of the hyperfine structure in the spectra of H\(_{3}\)\(^{+}\) and its deuterated isotopomers
Molecular Physics, 91 (2) :319-332
1997

716.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
An ab Initio Study of the NH2+ Absorption Spectrum
Journal of Molecular Spectroscopy, 186 (2) :319-334
1997

715.

Fink, Ewald H.; Shestakov, Oleg; Setzer, Klaus-Dieter
Fine Structure Transitions of BiOH in the Near-Infrared Region
Journal of Molecular Spectroscopy, 183 (1) :163-167
1997
Herausgeber: Academic Press

714.

Fink, Ewald H.; Shestakov, Oleg; Setzer, Klaus-Dieter
Fine Structure Transitions of BiOH in the Near-Infrared Region
Journal of Molecular Spectroscopy, 183 (1) :163-167
1997
Herausgeber: Academic Press

713.

Fink, Ewald H.; Shestakov, Oleg; Setzer, Klaus-Dieter
Fine Structure Transitions of BiOH in the Near-Infrared Region
Journal of Molecular Spectroscopy, 183 (1) :163-167
1997
Herausgeber: Academic Press

712.

Kirchner, Ulf; Benter, Thorsten; Schindler, Ralph N.
Experimental verification of gas phase bromine enrichment in reactions of HOBr with sea salt doped ice surfaces
Berichte der Bunsengesellschaft für physikalische Chemie, 101 (6) :975-977
1997

711.

Kirchner, Ulf; Benter, Thorsten; Schindler, Ralph N.
Experimental verification of gas phase bromine enrichment in reactions of HOBr with sea salt doped ice surfaces
Berichte der Bunsengesellschaft für physikalische Chemie, 101 (6) :975-977
1997

710.

Kirchner, Ulf; Benter, Thorsten; Schindler, Ralph N.
Experimental verification of gas phase bromine enrichment in reactions of HOBr with sea salt doped ice surfaces
Berichte der Bunsengesellschaft für physikalische Chemie, 101 (6) :975-977
1997

709.

Ehrhardt, M
Discrete transparent boundary conditions for parabolic equations
ZAMM-Zeitschrift fur Angewandte Mathematik und Mechanik, 77 (2) :543--544
1997
Herausgeber: Berlin, Akademie Verlag [etc.]

708.

Ehrhardt, M
Discrete transparent boundary conditions for parabolic equations
ZAMM-Zeitschrift fur Angewandte Mathematik und Mechanik, 77 (2) :543--544
1997
Herausgeber: Berlin, Akademie Verlag [etc.]

707.

Ehrgott, Matthias; Klamroth, Kathrin
Connectedness of efficient solutions in multiple criteria combinatorial optimization
European Journal of Operational Research, 97 :159-166
1997

706.

Spirko, Vladimír; Mengel, Markus; Jensen, Per
Calculation of Rotation-Vibration Energy Levels in Ground State C3 by a Born-Oppenheimer-Type Separation of the Vibrational Motions
Journal of Molecular Spectroscopy, 183 (1) :129-138
1997
Herausgeber: Academic Press

705.

Spirko, Vladim{í}r; Mengel, Markus; Jensen, Per
Calculation of Rotation-Vibration Energy Levels in Ground State C\(_{3}\) by a Born-Oppenheimer-Type Separation of the Vibrational Motions
Journal of Molecular Spectroscopy, 183 (1) :129-138
1997
Herausgeber: Academic Press

704.

Spirko, Vladim{í}r; Mengel, Markus; Jensen, Per
Calculation of Rotation-Vibration Energy Levels in Ground State C\(_{3}\) by a Born-Oppenheimer-Type Separation of the Vibrational Motions
Journal of Molecular Spectroscopy, 183 (1) :129-138
1997
Herausgeber: Academic Press

703.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
An ab Initio Study of the NH\(_{2}\)\(^{+}\) Absorption Spectrum
Journal of Molecular Spectroscopy, 186 (2) :319-334
1997

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