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



1996

618.

Kozin, Igor N.; Jensen, Per; Polanz, Oliver; Klee, Stefan; Poteau, Laurent; Demaison, Jean
The Rotational Spectrum of H2Te
Journal of Molecular Spectroscopy, 180 (2) :402-413
1996
Herausgeber: Academic Press

617.

Bunker, Philip R.; Jensen, Per; Yamaguchi, Yukio; Schaefer III, Henry F.
The Rovibrational Energy Levels of Quasilinear c\verb=~= \(^{1}\)A\(_{1}\) Methylene
Journal of Molecular Spectroscopy, 179 (2) :263-268
1996
Herausgeber: Academic Press

616.

Bunker, Philip R.; Jensen, Per; Yamaguchi, Yukio; Schaefer III, Henry F.
The Rovibrational Energy Levels of Quasilinear c\verb=~= \(^{1}\)A\(_{1}\) Methylene
Journal of Molecular Spectroscopy, 179 (2) :263-268
1996
Herausgeber: Academic Press

615.

Bunker, Philip R.; Jensen, Per; Yamaguchi, Yukio; Schaefer III, Henry F.
The Rovibrational Energy Levels of Quasilinear c~ 1A1 Methylene
Journal of Molecular Spectroscopy, 179 (2) :263-268
1996
Herausgeber: Academic Press

614.

Arste, J.; Klamroth, Kathrin; Mengersen, Ingrid
Three color Ramsey numbers for small graphs
Utilitas Mathematica, 49 :85--96
1996

613.

[german] Tausch, Michael W.
Ungleiche Gleichgewichte
{CHEMKON}, 3 (3) :123--127
1996
Herausgeber: Wiley
1995

612.

Mengel, Markus; Jensen, Per
A Theoretical Study of the Stark Effect in Triatomic Molecules: Application to H\(_{2}\)O
Journal of Molecular Spectroscopy, 169 (1) :73-91
1995
Herausgeber: Academic Press

611.

Mengel, Markus; Jensen, Per
A Theoretical Study of the Stark Effect in Triatomic Molecules: Application to H\(_{2}\)O
Journal of Molecular Spectroscopy, 169 (1) :73-91
1995
Herausgeber: Academic Press

610.

Mengel, Markus; Jensen, Per
A Theoretical Study of the Stark Effect in Triatomic Molecules: Application to H2O
Journal of Molecular Spectroscopy, 169 (1) :73-91
1995
Herausgeber: Academic Press

609.

Jensen, Per; Brumm, Martin; Kraemer, Wolfgang P.; Bunker, Philip R.
A Treatment of the Renner Effect Using the MORBID Hamiltonian
Journal of Molecular Spectroscopy, 171 (1) :31-57
1995
Herausgeber: Academic Press

608.

Jensen, Per; Brumm, Martin; Kraemer, Wolfgang P.; Bunker, Philip R.
A Treatment of the Renner Effect Using the MORBID Hamiltonian
Journal of Molecular Spectroscopy, 171 (1) :31-57
1995
Herausgeber: Academic Press

607.

Jensen, Per; Brumm, Martin; Kraemer, Wolfgang P.; Bunker, Philip R.
A Treatment of the Renner Effect Using the MORBID Hamiltonian
Journal of Molecular Spectroscopy, 171 (1) :31-57
1995
Herausgeber: Academic Press

606.

Jensen, Per; Brumm, Martin; Kraemer, Wolfgang P.; Bunker, Philip R.
An ab Initio Calculation of the Rovibronic Energies of the CH\(_{2}\)\(^{+}\) Molecule
Journal of Molecular Spectroscopy, 172 (1) :194-204
1995
Herausgeber: Academic Press

605.

Jensen, Per; Brumm, Martin; Kraemer, Wolfgang P.; Bunker, Philip R.
An ab Initio Calculation of the Rovibronic Energies of the CH\(_{2}\)\(^{+}\) Molecule
Journal of Molecular Spectroscopy, 172 (1) :194-204
1995
Herausgeber: Academic Press

604.

Jensen, Per; Brumm, Martin; Kraemer, Wolfgang P.; Bunker, Philip R.
An ab Initio Calculation of the Rovibronic Energies of the CH2+ Molecule
Journal of Molecular Spectroscopy, 172 (1) :194-204
1995
Herausgeber: Academic Press

603.

Gerstberger, R.; Günther, M.
Charge-oriented extrapolation methods in digital circuit simulation
Applied Numerical Mathematics, 18 (1) :115–125
1995
Herausgeber: Elsevier

602.

Gerstberger, Robert; Günther, Michael
Charge-oriented extrapolation methods in digital circuit simulation
Applied numerical mathematics, 18 (1-3) :115--125
1995
Herausgeber: North-Holland

601.

Flaud, Jean-Marie; Camy-Peyret, C.; B{ü}rger, H.; Jensen, Per; Kozin, Igor N.
Experimental evidence for the formation of fourfold rovibrational energy clusters in the \(\nu\)\(_{1}\)/\(\nu\)\(_{3}\) vibrational states of H\(_{2}\)\(^{80}\)Se
Journal of Molecular Spectroscopy, 172 (1) :126-134
1995
Herausgeber: Academic Press

600.

Flaud, Jean-Marie; Camy-Peyret, C.; B{ü}rger, H.; Jensen, Per; Kozin, Igor N.
Experimental evidence for the formation of fourfold rovibrational energy clusters in the \(\nu\)\(_{1}\)/\(\nu\)\(_{3}\) vibrational states of H\(_{2}\)\(^{80}\)Se
Journal of Molecular Spectroscopy, 172 (1) :126-134
1995
Herausgeber: Academic Press

599.

Flaud, Jean-Marie; Camy-Peyret, C.; Bürger, H.; Jensen, Per; Kozin, Igor N.
Experimental evidence for the formation of fourfold rovibrational energy clusters in the ν1/ν3 vibrational states of H280Se
Journal of Molecular Spectroscopy, 172 (1) :126-134
1995
Herausgeber: Academic Press

598.

Heilmann, Margareta
Explicit Voronovskaja-type results for linear combinations of BDT-operators
Approximation Theory and its Applications, 11 (1) :54-61
1995

597.

Ehrhardt, M.
Finite Differenzenverfahren für hyperbolische Systeme mit absorbierenden Randbedingungen
Technische Universität Berlin
1995

596.

Jensen, Per; Li, Yan; Hirsch, Gerhard; Buenker, Robert J.; Lee, Timothy J.; Kozin, Igor N.
Fourfold clusters of rovibrational energies in H\(_{2}\)Te studied with an ab initio potential energy function
Chemical Physics, 190 (2-3) :179-189
1995

595.

Jensen, Per; Li, Yan; Hirsch, Gerhard; Buenker, Robert J.; Lee, Timothy J.; Kozin, Igor N.
Fourfold clusters of rovibrational energies in H\(_{2}\)Te studied with an ab initio potential energy function
Chemical Physics, 190 (2-3) :179-189
1995

594.

Jensen, Per; Li, Yan; Hirsch, Gerhard; Buenker, Robert J.; Lee, Timothy J.; Kozin, Igor N.
Fourfold clusters of rovibrational energies in H2Te studied with an ab initio potential energy function
Chemical Physics, 190 (2-3) :179-189
1995