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



1991

359.

Jensen, Per; Marshall, Mark D.; Bunker, Philip R.; Karpfen, Alfred
An ab initio close-coupling calculation of the lower vibrational energies of the HCl dimer
Chemical Physics Letters, 180 (6) :594-600
1991

358.

Marshall, Mark D.; Jensen, Per; Bunker, Philip R.
An ab initio close-coupling calculation of the lower vibrational energies of the HF dimer
Chemical Physics Letters, 176 (3-4) :255-260
1991

357.

Marshall, Mark D.; Jensen, Per; Bunker, Philip R.
An ab initio close-coupling calculation of the lower vibrational energies of the HF dimer
Chemical Physics Letters, 176 (3-4) :255-260
1991

356.

Marshall, Mark D.; Jensen, Per; Bunker, Philip R.
An ab initio close-coupling calculation of the lower vibrational energies of the HF dimer
Chemical Physics Letters, 176 (3-4) :255-260
1991

355.

Karpfen, Alfred; Bunker, Philip R.; Jensen, Per
An ab initio study of the hydrogen chloride dimer: the potential energy surface and the characterization of the stationary points
Chemical Physics, 149 (3) :299-309
1991

354.

Karpfen, Alfred; Bunker, Philip R.; Jensen, Per
An ab initio study of the hydrogen chloride dimer: the potential energy surface and the characterization of the stationary points
Chemical Physics, 149 (3) :299-309
1991

353.

Karpfen, Alfred; Bunker, Philip R.; Jensen, Per
An ab initio study of the hydrogen chloride dimer: the potential energy surface and the characterization of the stationary points
Chemical Physics, 149 (3) :299-309
1991

352.

Bunker, Philip R.; Epa, V. C.; Jensen, Per; Karpfen, Alfred
An analytical ab initio potential surface and the calculated tunneling energies for the HCl dimer
Journal of Molecular Spectroscopy, 146 (1) :200-219
1991

351.

Bunker, Philip R.; Epa, V. C.; Jensen, Per; Karpfen, Alfred
An analytical ab initio potential surface and the calculated tunneling energies for the HCl dimer
Journal of Molecular Spectroscopy, 146 (1) :200-219
1991

350.

Bunker, Philip R.; Epa, V. C.; Jensen, Per; Karpfen, Alfred
An analytical ab initio potential surface and the calculated tunneling energies for the HCl dimer
Journal of Molecular Spectroscopy, 146 (1) :200-219
1991

349.

Fink, Ewald H.; Setzer, Klaus-Dieter; Wildt, J{ü}rgen; Ramsay, D. A.; Vervloet, M.
Collision-induced emission of O\(_{2}\)(b\(^{1}\)\(\Sigma\)\(_{g}\)\(^{+}\) → a\(^{1}\)\(\Delta\)\(_{g}\)) in the gas phase
International Journal of Quantum Chemistry, 39 (3) :287-298
1991

348.

Fink, Ewald H.; Setzer, Klaus-Dieter; Wildt, J{ü}rgen; Ramsay, D. A.; Vervloet, M.
Collision-induced emission of O\(_{2}\)(b\(^{1}\)\(\Sigma\)\(_{g}\)\(^{+}\) → a\(^{1}\)\(\Delta\)\(_{g}\)) in the gas phase
International Journal of Quantum Chemistry, 39 (3) :287-298
1991

347.

Fink, Ewald H.; Setzer, Klaus-Dieter; Wildt, Jürgen; Ramsay, D. A.; Vervloet, M.
Collision-induced emission of O2(b1Σg+ → a1Δg) in the gas phase
International Journal of Quantum Chemistry, 39 (3) :287-298
1991

346.

Vilesov, A. F.; Wildt, J{ü}rgen; Fink, Ewald H.
Emission of Xe: N(\(^{2}\)P) collision complexes near the N(\(^{2}\)P→\(^{2}\)D) lines
Chemical Physics, 153 (3) :531-537
1991

345.

Vilesov, A. F.; Wildt, J{ü}rgen; Fink, Ewald H.
Emission of Xe: N(\(^{2}\)P) collision complexes near the N(\(^{2}\)P→\(^{2}\)D) lines
Chemical Physics, 153 (3) :531-537
1991

344.

Vilesov, A. F.; Wildt, Jürgen; Fink, Ewald H.
Emission of Xe: N(2P) collision complexes near the N(2P→2D) lines
Chemical Physics, 153 (3) :531-537
1991

343.

Heilmann, Margareta; Müller, Manfred
Equivalence of a weighted modulus of smoothness and a modified weighted K-functional
In Nevai, P. and Pinkus, A., Editor
Herausgeber: Academic Press
1991

342.

Jensen, Per; Oddershede, Jens; Sabin, John R.
Geometric dependence of the mean excitation energy and spectral moments of water
Physical Review A, 43 (7) :4040-4043
1991

341.

Jensen, Per; Oddershede, Jens; Sabin, John R.
Geometric dependence of the mean excitation energy and spectral moments of water
Physical Review A, 43 (7) :4040-4043
1991

340.

Jensen, Per; Oddershede, Jens; Sabin, John R.
Geometric dependence of the mean excitation energy and spectral moments of water
Physical Review A, 43 (7) :4040-4043
1991

339.

Becker, Karl Heinz; Geiger, Harald; Wiesen, Peter
Kinetic study of the OH radical chain in the reaction system OH + C\(_{2}\)H\(_{4}\) + NO + air
Chemical Physics Letters, 184 (4) :256-261
1991

338.

Becker, Karl Heinz; Geiger, Harald; Wiesen, Peter
Kinetic study of the OH radical chain in the reaction system OH + C\(_{2}\)H\(_{4}\) + NO + air
Chemical Physics Letters, 184 (4) :256-261
1991

337.

Becker, Karl Heinz; Geiger, Harald; Wiesen, Peter
Kinetic study of the OH radical chain in the reaction system OH + C2H4 + NO + air
Chemical Physics Letters, 184 (4) :256-261
1991

336.

Wildt, J{ü}rgen; Bednarek, G.; Fink, Ewald H.; Wayne, Richard P.
Laser excitation of the A\(^{3}\)\(\Sigma\)\(_{u}\)\(^{+}\), A'\(^{3}\)\(\Delta\)\(_{u}\) and c\(^{1}\)\(\Sigma\)\(_{u}\)\(^{-}\) states of molecular oxygen
Chemical Physics, 156 (3) :497-508
1991

335.

Wildt, J{ü}rgen; Bednarek, G.; Fink, Ewald H.; Wayne, Richard P.
Laser excitation of the A\(^{3}\)\(\Sigma\)\(_{u}\)\(^{+}\), A'\(^{3}\)\(\Delta\)\(_{u}\) and c\(^{1}\)\(\Sigma\)\(_{u}\)\(^{-}\) states of molecular oxygen
Chemical Physics, 156 (3) :497-508
1991