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



1997

743.

G{{\'o}}mez, P. C.; Jensen, Per
A potential energy surface for the electronic ground state of H\(_{2}\)Te derived from experiment
Journal of Molecular Spectroscopy, 185 (2) :282-289
1997
Herausgeber: Academic Press

742.

Gómez, P. C.; Jensen, Per
A potential energy surface for the electronic ground state of H2Te derived from experiment
Journal of Molecular Spectroscopy, 185 (2) :282-289
1997
Herausgeber: Academic Press

741.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
A theoretical calculation of the absorption spectrum of CH\(_{2}\)\(^{+}\)
Chemical Physics, 225 (1-3) :33-54
1997
Herausgeber: North-Holland

740.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
A theoretical calculation of the absorption spectrum of CH\(_{2}\)\(^{+}\)
Chemical Physics, 225 (1-3) :33-54
1997
Herausgeber: North-Holland

739.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
A theoretical calculation of the absorption spectrum of CH2+
Chemical Physics, 225 (1-3) :33-54
1997
Herausgeber: North-Holland

738.

Kozin, Igor N.; Jensen, Per; Li, Yan; Buenker, Robert J.; Hirsch, Gerhard; Klee, Stefan
An ab initio calculation of the dipole moment surfaces and the vibrational transition moments of the H\(_{2}\)Te molecule
Journal of Molecular Spectroscopy, 181 (1) :108-118
1997
Herausgeber: Academic Press

737.

Kozin, Igor N.; Jensen, Per; Li, Yan; Buenker, Robert J.; Hirsch, Gerhard; Klee, Stefan
An ab initio calculation of the dipole moment surfaces and the vibrational transition moments of the H\(_{2}\)Te molecule
Journal of Molecular Spectroscopy, 181 (1) :108-118
1997
Herausgeber: Academic Press

736.

Kozin, Igor N.; Jensen, Per; Li, Yan; Buenker, Robert J.; Hirsch, Gerhard; Klee, Stefan
An ab initio calculation of the dipole moment surfaces and the vibrational transition moments of the H2Te molecule
Journal of Molecular Spectroscopy, 181 (1) :108-118
1997
Herausgeber: Academic Press

735.

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

734.

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

733.

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

732.

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

731.

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

730.

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

729.

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

728.

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

727.


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

726.

Ehrhardt, Matthias
Discrete transparent boundary conditions for parabolic equations
ZAMM-Zeitschrift fur Angewandte Mathematik und Mechanik, 77 (S2) :S543–S592
1997
Herausgeber: WILEY-VCH Verlag

725.

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

724.

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

723.

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

722.

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

721.

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

720.

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

719.

G{{\'o}}mez, P. C.; Pacios, L. F.; Jensen, Per
Fourfold Clusters of Rovibrational Energies in H\(_{2}\)Po Studied with an ab Initio Potential Energy Function
Journal of Molecular Spectroscopy, 186 (1) :99-104
1997
Herausgeber: Academic Press