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



2001

1054.

G\"unther, Michael; Rentrop, P.; Feldmann, U.
CHORAL - a one step method as numerical low pass filter in electrical network analysis
In {van Rienen}, U. and G\"unther, M. and Hecht, D., Editor, Scientific Computing in Electrical Engineering. Proceedings of the 3rd International Workshop, 20-23 August 2000, Warnem\"unde, Germany, Seite 199--215
In {van Rienen}, U. and G\"unther, M. and Hecht, D., Editor
Herausgeber: Springer-Verlag, Berlin
2001

1053.

Farkas, Bálint; Matolcsi, Máté
Commutation properties of the form sum of positive, symmetric operators
Acta Sci. Math. (Szeged), 67 (3-4) :777-790
2001

1052.

Bartel, Andreas; G\"unther, Michael
Developments in Multirating for Coupled Systems
Z. angew. Math. Mech., 81 Suppl. 3 :S739-S742
2001

1051.

Günther, Michael; Hoschek, Markus; Rentrop, Peter
Differential-algebraic equations in electric circuit simulation
Int. J. Electron. Commun. (AE\"U), 54 :101--107
2001

1050.

Ehrhardt, Matthias
Discrete artificial boundary conditions
Ph.D. Thesis, Technische Universität Berlin, 2001.
2001

1049.

Ehrhardt, M.
Discrete Artificial Boundary Conditons
Technische Universität Berlin
2001

1048.

Ehrhardt, Matthias
Discrete transparent boundary conditions for the Schrödinger equation
Rivista di Mathematica della Universita di Parma, 6 (4) :57–108
2001
Herausgeber: Università di Parma

1047.

Ehrhardt, Matthias
Discrete transparent boundary conditions for the Schrödinger equation
2001

1046.

Tausch, Michael W.; Schmitz, R.-P.
Ein Hypermedia-Lernnetz: Natriumchlorid und Ionenbindung
Praxis der Naturwissenschaften - Chemie in der Schule, 50 (7) :36
2001

1045.

Woock, Michael; Tausch, Michael W.
Es tropft, Herr Lehrer - die Synthese von {MTBE} im Schulexperiment
{CHEMKON}, 8 (2) :86--90
2001
Herausgeber: Wiley

1044.

Jacob, Birgit; Zwart, Hans
Exact controllability of C_0-groups with one-dimensional input operators
Advances in mathematical systems theory aus Systems Control Found. Appl.
Seite 221--242
Herausgeber: Birkhäuser Boston, Boston, MA
2001
221--242

1043.

Jacob, Birgit; Zwart, Hans
Exact observability of diagonal systems with a finite-dimensional output operator
Systems Control Lett., 43 (2) :101--109
2001

1042.

Jacob, Birgit; Zwart, Hans
Exact observability of diagonal systems with a one-dimensional output operator
, Band 11
Seite 1277--1283
2001
1277--1283

1041.

Setzer, Klaus-Dieter; Fink, Ewald H.; Alekseyev, Aleksey B.; Liebermann, Heinz-Peter; Buenker, Robert J.
Experimental and Theoretical Study of the Electronic States and Spectra of TeH and TeLi
Journal of Molecular Spectroscopy, 206 (2) :181-197
2001
Herausgeber: Academic Press

1040.

Setzer, Klaus-Dieter; Fink, Ewald H.; Alekseyev, Aleksey B.; Liebermann, Heinz-Peter; Buenker, Robert J.
Experimental and Theoretical Study of the Electronic States and Spectra of TeH and TeLi
Journal of Molecular Spectroscopy, 206 (2) :181-197
2001
Herausgeber: Academic Press

1039.

Setzer, Klaus-Dieter; Fink, Ewald H.; Alekseyev, Aleksey B.; Liebermann, Heinz-Peter; Buenker, Robert J.
Experimental and Theoretical Study of the Electronic States and Spectra of TeH and TeLi
Journal of Molecular Spectroscopy, 206 (2) :181-197
2001
Herausgeber: Academic Press

1038.

J{\o}rgensen, Uffe G.; Jensen, Per; S{\o}rensen, G. O.; Aringer, B.
H\(_{2}\)O in stellar atmospheres
Astronomy \& Astrophysics, 372 (1) :249-259
2001
Herausgeber: EDP Sciences

1037.

J{\o}rgensen, Uffe G.; Jensen, Per; S{\o}rensen, G. O.; Aringer, B.
H\(_{2}\)O in stellar atmospheres
Astronomy \& Astrophysics, 372 (1) :249-259
2001
Herausgeber: EDP Sciences

1036.

Jørgensen, Uffe G.; Jensen, Per; Sørensen, G. O.; Aringer, B.
H2O in stellar atmospheres
Astronomy & Astrophysics, 372 (1) :249-259
2001
Herausgeber: EDP Sciences

1035.

Favier, Fr{é}d{é}ric; Walter, Erich C.; Zach, Michael P.; Benter, Thorsten; Penner, Reginald M.
Hydrogen Sensors and Switches from Electrodeposited Palladium Mesowire Arrays
Science, 293 (5538) :2227-2231
2001

1034.

Favier, Frédéric; Walter, Erich C.; Zach, Michael P.; Benter, Thorsten; Penner, Reginald M.
Hydrogen Sensors and Switches from Electrodeposited Palladium Mesowire Arrays
Science, 293 (5538) :2227-2231
2001

1033.

Favier, Fr{é}d{é}ric; Walter, Erich C.; Zach, Michael P.; Benter, Thorsten; Penner, Reginald M.
Hydrogen Sensors and Switches from Electrodeposited Palladium Mesowire Arrays
Science, 293 (5538) :2227-2231
2001

1032.

[german] Tausch, Michael W.; Woock, M.
Hypermedia-Baustein: MTBE im Kraftstoff
Praxis der Naturwissenschaften - Chemie in der Schule, 50 (7) :24
2001

1031.

[german] Bohrmann, Claudia; Tausch, Michael W.
Hypermedia-Baustein: Photoelektrochemische Zelle
Praxis der Naturwissenschaften - Chemie in der Schule, 50 (7)
2001

1030.

Günther, Michael; Wagner, Yvonne
Index concepts for linear mixed systems of differential-algebraic and hyperbolic-type equations
SIAM Journal on Scientific Computing, 22 (5) :1610–1629
2001