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

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

DOI: 10.1021/ac9901900

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

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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

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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

DOI: 10.1021/jp9906841

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

DOI: 10.1021/jp9906841

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

DOI: 10.1021/jp9906841

869.

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

DOI: 10.1016/S0167-6911(99)00019-5

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

DOI: 10.1016/S0009-2614(99)00682-X

867.

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

DOI: 10.1016/S0009-2614(99)00682-X

866.

Osmann, Gerald; Bunker, Philip R.; Kraemer, Wolfgang P.; Jensen, Per
Coulomb explosion imaging and the CH2+ molecule
Chemical Physics Letters, 309 (3-4) :299-306
1999

DOI: 10.1016/S0009-2614(99)00682-X

865.

Korn, Silke; Eisel, Christian; Tausch, Michael W.
Das leuchtende Labor
{CHEMKON}, 6 (3) :142--142
1999
Herausgeber: Wiley

DOI: 10.1002/ckon.19990060308

864.

Tyuterev, Vladimir G.; Tashkun, Sergey A.; Jensen, Per; Barbe, Alain; Cours, T.
Determination of the Effective Ground State Potential Energy Function of Ozone from High-Resolution Infrared Spectra
Journal of Molecular Spectroscopy, 198 (1) :57-76
1999

DOI: 10.1006/jmsp.1999.7928

863.

Tyuterev, Vladimir G.; Tashkun, Sergey A.; Jensen, Per; Barbe, Alain; Cours, T.
Determination of the Effective Ground State Potential Energy Function of Ozone from High-Resolution Infrared Spectra
Journal of Molecular Spectroscopy, 198 (1) :57-76
1999

DOI: 10.1006/jmsp.1999.7928

862.

Tyuterev, Vladimir G.; Tashkun, Sergey A.; Jensen, Per; Barbe, Alain; Cours, T.
Determination of the Effective Ground State Potential Energy Function of Ozone from High-Resolution Infrared Spectra
Journal of Molecular Spectroscopy, 198 (1) :57-76
1999

DOI: 10.1006/jmsp.1999.7928

861.

Ehrhardt, Matthias
Discrete transparent boundary conditions for general Schrödinger-type equations
VLSI Design, 9 (4) :325–338
1999
Herausgeber: Hindawi Publishing

DOI: 10.1155/1999/72984

860.


Discrete transparent boundary conditions for general Schrödinger-type equations
Computer Physics Communications, 121 (4) :598--598
1999
Herausgeber: Hindawi

859.

[german] Tausch, Michael W.; Grolmuss, A.
Ein low-cost Selbstbau-Spektroskop
Praxis der Naturwissenschaften (Chemie), 48 (7) :36
1999

858.

Zwart, Hans; Jacob, Birgit
Equivalent conditions for stabilizability of infinite-dimensional systems with admissible control operators
SIAM J. Control Optim., 37 (5) :1419--1455
1999

DOI: 10.1137/S036301299833344X

857.

Chudej, Kurt; Günther, Michael
Global state space approach for the efficient numerical solution of state-constrained trajectory optimization problems
Journal of optimization theory and applications, 103 :75--93
1999
Herausgeber: Kluwer Academic Publishers-Plenum Publishers

856.

Kleffmann, Jörg; Becker, Karl Heinz; Lackhoff, Marion; Wiesen, Peter
Heterogeneous conversion of NO\(_{2}\) on carbonaceous surfaces
Physical Chemistry Chemical Physics, 1 (24) :5443-5450
1999
Herausgeber: The Royal Society of Chemistry

DOI: 10.1039/a905545b

855.

Kleffmann, Jörg; Becker, Karl Heinz; Lackhoff, Marion; Wiesen, Peter
Heterogeneous conversion of NO\(_{2}\) on carbonaceous surfaces
Physical Chemistry Chemical Physics, 1 (24) :5443-5450
1999
Herausgeber: The Royal Society of Chemistry

DOI: 10.1039/a905545b

854.

Kleffmann, Jörg; Becker, Karl Heinz; Lackhoff, Marion; Wiesen, Peter
Heterogeneous conversion of NO2 on carbonaceous surfaces
Physical Chemistry Chemical Physics, 1 (24) :5443-5450
1999
Herausgeber: The Royal Society of Chemistry

DOI: 10.1039/a905545b

853.

Setzer, Klaus-Dieter; Fink, Ewald H.; Ramsay, D. A.
High-Resolution Fourier-Transform Study of the b\(^{1}\)\(\Sigma\)\(^{+}\) → X\(^{3}\)\(\Sigma\)\(^{-}\) and a\(^{1}\)\(\Delta\) → X\(^{3}\)\(\Sigma\)\(^{-}\) Transitions of SO
Journal of Molecular Spectroscopy, 198 (1) :163-174
1999
Herausgeber: Academic Press

DOI: 10.1006/jmsp.1999.7943

852.

Setzer, Klaus-Dieter; Fink, Ewald H.; Ramsay, D. A.
High-Resolution Fourier-Transform Study of the b\(^{1}\)\(\Sigma\)\(^{+}\) → X\(^{3}\)\(\Sigma\)\(^{-}\) and a\(^{1}\)\(\Delta\) → X\(^{3}\)\(\Sigma\)\(^{-}\) Transitions of SO
Journal of Molecular Spectroscopy, 198 (1) :163-174
1999
Herausgeber: Academic Press

DOI: 10.1006/jmsp.1999.7943

851.

Setzer, Klaus-Dieter; Fink, Ewald H.; Ramsay, D. A.
High-Resolution Fourier-Transform Study of the b1Σ+ → X3Σ- and a1Δ → X3Σ- Transitions of SO
Journal of Molecular Spectroscopy, 198 (1) :163-174
1999
Herausgeber: Academic Press

DOI: 10.1006/jmsp.1999.7943