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



2000

892.

Tyuterev, Vladimir G.; Tashkun, Sergey A.; Schwenke, D. W.; Jensen, Per; Cours, T.; Barbe, Alain; Jacon, M.
Variational EKE-calculations of rovibrational energies of the ozone molecule from an empirical potential function
Chemical Physics Letters, 316 (3-4) :271-279
2000

891.

Schneider, Gisbert; Hilfiger, Laurence; Schneider, Petra; Kirsch, Stefan; Böhm, Hans-Joachim; Neidhart, Werner
Virtual Screening for Bioactive Molecules by Evolutionary De Novo Design
Angewandte Chemie, 39 (22) :4130–4133
2000
ISSN: 14337851, 15213773
1999

890.

P. Schmitz, R.; Eisel, C.; Korn, S.; Tausch, Michael W.
''Chemie interaktiv'', Multimedia CD mit Lernsoftware für Schülerinnen und Schüler
Online
1999

889.

Eisel, C.; Korn, S.; Schmitz, R.-P.; Tausch, Michael W.
''Duisburger Chemiedidaktik im WWW'' (Materialien für den Chemieunterricht, Präsentationen zu Vorträgen im Rahmen der Lehrerfortbildung u.a.)
Online
1999

888.

Chudej, K.; Günther, M.
A global state space approach for the efficient numerical solution of state-constrained trajectory optimization problems
Journal of Optimization Theory and Applications, 103 (1) :75–93
1999
Herausgeber: Springer New York

887.

Chudej, K.; G\"unther, Michael
A global state space approach for the efficient numerical solution of state-constrained trajectory optimization problems
J. Optim. Theory Appl., 103 (1) :75--93
1999

886.

Geiger, Harald; Wiesen, Peter; Becker, Karl Heinz
A product study of the reaction of CH radicals with nitric oxide at 298 K
Physical Chemistry Chemical Physics, 1 (24) :5601-5606
1999

885.

Geiger, Harald; Wiesen, Peter; Becker, Karl Heinz
A product study of the reaction of CH radicals with nitric oxide at 298 K
Physical Chemistry Chemical Physics, 1 (24) :5601-5606
1999

884.

Geiger, Harald; Wiesen, Peter; Becker, Karl Heinz
A product study of the reaction of CH radicals with nitric oxide at 298 K
Physical Chemistry Chemical Physics, 1 (24) :5601-5606
1999

883.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Buenker, Robert J.; Gu, Jian-ping; Hirsch, Gerhard
A Theoretical Investigation of the Renner Interactions and Magnetic Dipole Transitions in the A\verb=~=-X\verb=~= Electronic Band System of HO\(_{2}\)
Journal of Molecular Spectroscopy, 197 (2) :262-274
1999
Herausgeber: Academic Press

882.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Buenker, Robert J.; Gu, Jian-ping; Hirsch, Gerhard
A Theoretical Investigation of the Renner Interactions and Magnetic Dipole Transitions in the A\verb=~=-X\verb=~= Electronic Band System of HO\(_{2}\)
Journal of Molecular Spectroscopy, 197 (2) :262-274
1999
Herausgeber: Academic Press

881.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Buenker, Robert J.; Gu, Jian-ping; Hirsch, Gerhard
A Theoretical Investigation of the Renner Interactions and Magnetic Dipole Transitions in the A~-X~ Electronic Band System of HO2
Journal of Molecular Spectroscopy, 197 (2) :262-274
1999
Herausgeber: Academic Press

880.

Benter, Thorsten; Appel, Matthew F.; Garnica, R. M.; Schmidt, Sven; Schindler, Ralph N.
Atmospheric pressure laser ionization mass spectrometry (APLI MS): Potential analytical applications in medical diagnostics and environmental chemistry.
Abstracts of Papers of The Americal Chemical Society, 218 (1) :U174-U175
1999

879.

Benter, Thorsten; Appel, Matthew F.; Garnica, R. M.; Schmidt, Sven; Schindler, Ralph N.
Atmospheric pressure laser ionization mass spectrometry (APLI MS): Potential analytical applications in medical diagnostics and environmental chemistry.
Abstracts of Papers of The Americal Chemical Society, 218 (1) :U174-U175
1999

878.

Benter, Thorsten; Appel, Matthew F.; Garnica, R. M.; Schmidt, Sven; Schindler, Ralph N.
Atmospheric pressure laser ionization mass spectrometry (APLI MS): Potential analytical applications in medical diagnostics and environmental chemistry.
Abstracts of Papers of The Americal Chemical Society, 218 (1) :U174-U175
1999

877.

Schmidt, Sven; Appel, Matthew F.; Garnica, R. M.; Schindler, Ralph N.; Benter, Thorsten
Atmospheric Pressure Laser Ionization. An Analytical Technique for Highly Selective Detection of Ultralow Concentrations in the Gas Phase
Analytical Chemistry, 71 (17) :3721-3729
1999

876.

Schmidt, Sven; Appel, Matthew F.; Garnica, R. M.; Schindler, Ralph N.; Benter, Thorsten
Atmospheric Pressure Laser Ionization. An Analytical Technique for Highly Selective Detection of Ultralow Concentrations in the Gas Phase
Analytical Chemistry, 71 (17) :3721-3729
1999

875.

Schmidt, Sven; Appel, Matthew F.; Garnica, R. M.; Schindler, Ralph N.; Benter, Thorsten
Atmospheric Pressure Laser Ionization. An Analytical Technique for Highly Selective Detection of Ultralow Concentrations in the Gas Phase
Analytical Chemistry, 71 (17) :3721-3729
1999

874.

Günther, M.; Feldmann, U.
CAD-based electric circuit modeling in industry I: mathematical structure and index of network equations
Surveys on Mathematics for Industry, 8 :97–129
1999
Herausgeber: Springer

873.

Günther, M.; Feldmann, U.
CAD-based electric circuit modeling in industry II: impact of circuit configurations and parameters
Surveys on Mathematics for Industry, 8 :131–157
1999
Herausgeber: Springer

872.

Caldwell, Tracy E.; Foster, Krishna L.; Benter, Thorsten; Langer, Sarka; Hemminger, John C.; Finlayson-Pitts, Barbara J.
Characterization of HOCl Using Atmospheric Pressure Ionization Mass Spectrometry
The Journal of Physical Chemistry A, 103 (41) :8231-8238
1999

871.

Caldwell, Tracy E.; Foster, Krishna L.; Benter, Thorsten; Langer, Sarka; Hemminger, John C.; Finlayson-Pitts, Barbara J.
Characterization of HOCl Using Atmospheric Pressure Ionization Mass Spectrometry
The Journal of Physical Chemistry A, 103 (41) :8231-8238
1999

870.

Caldwell, Tracy E.; Foster, Krishna L.; Benter, Thorsten; Langer, Sarka; Hemminger, John C.; Finlayson-Pitts, Barbara J.
Characterization of HOCl Using Atmospheric Pressure Ionization Mass Spectrometry
The Journal of Physical Chemistry A, 103 (41) :8231-8238
1999

869.

Jacob, Birgit; Winkin, Joseph; Zwart, Hans
Continuity of the spectral factorization on a vertical strip
Systems Control Lett., 37 (4) :183--192
1999

868.

Osmann, Gerald; Bunker, Philip R.; Kraemer, Wolfgang P.; Jensen, Per
Coulomb explosion imaging and the CH\(_{2}\)\(^{+}\) molecule
Chemical Physics Letters, 309 (3-4) :299-306
1999