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

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, J{ö}rg; 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, J{ö}rg; 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

850.

Gänsheimer, S; Schilling, A
Improved staging of prostate cancer using a new tumorscore
Aktuelle Urologie, 30 (1) :20--26
1999
Herausgeber: GEORG THIEME VERLAG KG RUDIGERSTR 14, D-70469 STUTTGART, GERMANY

849.

Becker, Karl Heinz; Geiger, Harald; Schmidt, Frank; Wiesen, Peter
Kinetic investigation of NCO radicals reacting with selected hydrocarbons
Physical Chemistry Chemical Physics, 1 (23) :5305-5309
1999

DOI: 10.1039/a906351j

848.

Becker, Karl Heinz; Geiger, Harald; Schmidt, Frank; Wiesen, Peter
Kinetic investigation of NCO radicals reacting with selected hydrocarbons
Physical Chemistry Chemical Physics, 1 (23) :5305-5309
1999

DOI: 10.1039/a906351j

847.

Becker, Karl Heinz; Geiger, Harald; Schmidt, Frank; Wiesen, Peter
Kinetic investigation of NCO radicals reacting with selected hydrocarbons
Physical Chemistry Chemical Physics, 1 (23) :5305-5309
1999

DOI: 10.1039/a906351j

846.

Becker, Karl Heinz; Dinis, Carlos M.; Geiger, Harald; Wiesen, Peter
Kinetics of the reaction of OH with di-n-butoxymethane (DBM) in the range 298-710 K
Chemical Physics Letters, 300 (3-4) :460-464
1999

DOI: 10.1016/S0009-2614(98)01396-7

845.

Becker, Karl Heinz; Dinis, Carlos M.; Geiger, Harald; Wiesen, Peter
Kinetics of the reaction of OH with di-n-butoxymethane (DBM) in the range 298-710 K
Chemical Physics Letters, 300 (3-4) :460-464
1999

DOI: 10.1016/S0009-2614(98)01396-7

844.

Becker, Karl Heinz; Dinis, Carlos M.; Geiger, Harald; Wiesen, Peter
Kinetics of the reaction of OH with di-n-butoxymethane (DBM) in the range 298-710 K
Chemical Physics Letters, 300 (3-4) :460-464
1999

DOI: 10.1016/S0009-2614(98)01396-7

843.

Foster, Krishna L.; Lakin, M. J.; Caldwell, Tracy E.; Hemminger, John C.; Benter, Thorsten; Finlayson-Pitts, Barbara J.
Laboratory studies of model sea-salt aerosols with HOCl.
Abstracts of Papers of The Americal Chemical Society, 217 (1) :U109
1999

842.

Foster, Krishna L.; Lakin, M. J.; Caldwell, Tracy E.; Hemminger, John C.; Benter, Thorsten; Finlayson-Pitts, Barbara J.
Laboratory studies of model sea-salt aerosols with HOCl.
Abstracts of Papers of The Americal Chemical Society, 217 (1) :U109
1999

841.

Foster, Krishna L.; Lakin, M. J.; Caldwell, Tracy E.; Hemminger, John C.; Benter, Thorsten; Finlayson-Pitts, Barbara J.
Laboratory studies of model sea-salt aerosols with HOCl.
Abstracts of Papers of The Americal Chemical Society, 217 (1) :U109
1999

840.

Korn, S.; Eisel, C.; Schmitz, R.-P.; Tausch, Michael W.
Licht - die vergessene Energieform oder chemische Licht - Spiele in 6 Akten'', Multimedia CD mit Materialien für den Unterricht
Online
1999

839.

Jacob, Birgit
Linear quadratic optimal control of time-varying systems with indefinite costs on Hilbert spaces
Math. Control Signals Systems, 12 (2) :196--218
1999

DOI: 10.1007/PL00009850

838.

[english] Eisel, Christian; Tausch, Michael W.
Molecular hydrogen from hydrochloric acid and copper under UV light irradiation
Journal of Photochemistry and Photobiology A: Chemistry, 128 (1-3) :151--154
1999
Herausgeber: Elsevier {BV}

DOI: 10.1016/s1010-6030(99)00166-5

837.

Becker, Karl Heinz; L{ö}rzer, Jutta C.; Kurtenbach, Ralf; Wiesen, Peter; Jensen, T. E.; Wallington, T. J.
Nitrous oxide (N\(_{2}\)O) emissions from vehicles
Environmental Science and Technology, 33 (22) :4134-4139
1999

DOI: 10.1021/es9903330

836.

Becker, Karl Heinz; L{ö}rzer, Jutta C.; Kurtenbach, Ralf; Wiesen, Peter; Jensen, T. E.; Wallington, T. J.
Nitrous oxide (N\(_{2}\)O) emissions from vehicles
Environmental Science and Technology, 33 (22) :4134-4139
1999

DOI: 10.1021/es9903330