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



2004

1342.

Bludský, Ota; Spirko, Vladimír; Odaka, Tina Erica; Jensen, Per; Hirano, Tsuneo
A theoretical study of the MgNC/MgCN isomerization in the electronic ground state
Journal of Molecular Structure, 695-696 :219-226
2004
Herausgeber: Elsevier

1341.

Jacob, Birgit; Partington, Jonathan R.
Admissibility of control and observation operators for semigroups: a survey
, Current trends in operator theory and its applications Band 149 aus Oper. Theory Adv. Appl.
Seite 199--221
Herausgeber: Birkhäuser, Basel
2004
199--221

1340.

Jacob, Birgit; Partington, Jonathan R.
Admissible control and observation operators for Volterra integral equations
J. Evol. Equ., 4 (3) :333--343
2004

1339.

Klamroth, Kathrin
Algebraic properties of location problems with one circular barrier
European Journal of Operational Research, 154 :20-35
2004

1338.

Ehrgott, Matthias; Klamroth, Kathrin; Schwehm, Christian
An MCDM approach to portfolio optimization
European Journal of Operational Research, 155 :752-770
2004

1337.

Tausch, Michael W.; Wachtendonk, Magdalene; Bohrmann-Linde, Claudia; Krollmann, P.; Schmitz, W.; Wambach-Laicher, J.
CHEMIE 2000+ Band 3.1, Lehrbuch für die gymnasiale Oberstufe
Herausgeber: C.C.Buchner, Bamberg
2004

1336.

Bunker, Philip R.; Jensen, Per
Chirality in rotational energy level clusters
Journal of Molecular Spectroscopy, 228 (2) :640-644
2004
Herausgeber: Academic Press

1335.

Bunker, Philip R.; Jensen, Per
Chirality in rotational energy level clusters
Journal of Molecular Spectroscopy, 228 (2) :640-644
2004
Herausgeber: Academic Press

1334.

Bunker, Philip R.; Jensen, Per
Chirality in rotational energy level clusters
Journal of Molecular Spectroscopy, 228 (2) :640-644
2004
Herausgeber: Academic Press

1333.

Jacob, Birgit; Zwart, Hans
Counterexamples concerning observation operators for C_0-semigroups
SIAM J. Control Optim., 43 (1) :137--153
2004

1332.

Tausch, Michael W.
Curriculare Innovation
Praxis der Naturwissenschaften - Chemie in der Schule, 53 (8) :18--21
2004

1331.

Appel, Matthew F.; Short, Luke Chandler; Benter, Thorsten
Development of medium pressure laser ionization, MPLI. Description of the MPLI ion source
Journal of the American Society for Mass Spectrometry, 15 (12) :1885-1896
2004

1330.

Appel, Matthew F.; Short, Luke Chandler; Benter, Thorsten
Development of medium pressure laser ionization, MPLI. Description of the MPLI ion source
Journal of the American Society for Mass Spectrometry, 15 (12) :1885-1896
2004

1329.

Appel, Matthew F.; Short, Luke Chandler; Benter, Thorsten
Development of medium pressure laser ionization, MPLI. Description of the MPLI ion source
Journal of the American Society for Mass Spectrometry, 15 (12) :1885-1896
2004

1328.

Stiglmayr, Michael
Die Bedeutung von Abstandsmaßen in der Data Envelopment Analysis
Diploma Thesis
Diploma Thesis
Universität Erlangen - Nürnberg, Institut für Angewandte Mathematik
2004

1327.

Tausch, Michael W.; Maibaum, R.; Seesing, M.; Knauf, U.; Twellmann, M.; Grolmuss, A.; Schmitz, R.-P-; Zimnol, V.; Trzaska, T.; Szemenyei, M.
DISCOVERING SILICONES DOCUMENTATION, CD-ROM
Online / CD-Rom
2004

1326.

Ehrhardt, Matthias
Discrete Transparent Boundary Conditions for Time-Dependent Systems of Schrödinger Equations
2004

1325.

Ehrhardt, Matthias
Discrete transparent boundary conditions for time-dependent systems of Schrödinger equations
Preprint, Research Center Matheon :1–26
2004
Herausgeber: Technische Universität Berlin

1324.

Ehrhardt, Matthias
Discrete transparent boundary conditions for wide angle parabolic equations: Fast calculation and approximation
:9--14
2004

1323.

Ehrhardt, Matthias
Discrete transparent boundary conditions for wide angle parabolic equations: Fast calculation and approximation
Seventh European Conference on Underwater Acoustics, Seite 9–14
2004

1322.

Simeon, Bernd; Günther, Michael; Schaub, Meike
Einführung in MATLAB
2004

1321.

Tausch, Michael W.
Excited States ... the Heart of all Photoprocesses
Praxis der Naturwissenschaften - Chemie in der Schule, 53 (3) :1
2004

1320.

Tausch, Michael W.; Gärtner, F.
Fluoreszenzkollektoren
Praxis der Naturwissenschaften - Chemie in der Schule, 53 (3) :20
2004

1319.

Kleffmann, Jörg; Benter, Thorsten; Wiesen, Peter
Heterogeneous reaction of nitric acid with nitric oxide on glass surfaces under simulated atmospheric conditions
Journal of Physical Chemistry A, 108 (27) :5793-5799
2004

1318.

Kleffmann, Jörg; Benter, Thorsten; Wiesen, Peter
Heterogeneous reaction of nitric acid with nitric oxide on glass surfaces under simulated atmospheric conditions
Journal of Physical Chemistry A, 108 (27) :5793-5799
2004