Magnetics

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.

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

Efficiency of the time-integration for field devices in pulsed circuits (multirate, dynamic iteration)
DAE-index of the coupled system
Existence and Uniqueness of the solution

Cooperation

Herbert De Gersem, Katholieke Universiteit Leuven
Markus Clemens, Bergische Universität Wuppertal
Sascha Baumanns, Universität zu Köln

Former and ongoing projects

Publications

1989: 253.
Becker, Karl Heinz; Engelhardt, B.; Wiesen, Peter; Bayes, Kyle D.
Rate constants for CH(X2Π) reactions at low total pressures
Chemical Physics Letters, 154 (4) :342-348
1989
DOI: 10.1016/0009-2614(89)85367-9; 252.
Becker, Karl Heinz; Engelhardt, B.; Wiesen, Peter; Bayes, Kyle D.
Rate constants for CH(X\(^{2}\)\(\Pi\)) reactions at low total pressures
Chemical Physics Letters, 154 (4) :342-348
1989
DOI: 10.1016/0009-2614(89)85367-9; 251.
Becker, Karl Heinz; Engelhardt, B.; Wiesen, Peter; Bayes, Kyle D.
Rate constants for CH(X\(^{2}\)\(\Pi\)) reactions at low total pressures
Chemical Physics Letters, 154 (4) :342-348
1989
DOI: 10.1016/0009-2614(89)85367-9; 250.
[german] Tausch, Michael W.; Wöhrle, D.
Photokatalyse
Praxis der Naturwissenschaften (Chemie), 38 :37
1989
Download; 249.
Heilmann, Margareta; Müller, Manfred
On simultaneous approximation by the method of Baskakov-Durrmeyer operators
Numerical Functional Analysis and Optimization, 10 (1-2) :127-138
1989
DOI: 10.1080/01630568908816295; 248.
Heilmann, Margareta
On simultaneous approximation by optimal algebraic polynomials
Results in Mathematics, 16 (1-2) :77-81
1989
DOI: 10.1007/BF03322645; 247.
Fink, Ewald H.; Setzer, Klaus-Dieter; Ramsay, D. A.; Vervloet, M.
Near-infrared emission bands of TeH and TeD
Journal of Molecular Spectroscopy, 138 (1) :19-28
1989
DOI: 10.1016/0022-2852(89)90094-5; 246.
Fink, Ewald H.; Setzer, Klaus-Dieter; Ramsay, D. A.; Vervloet, M.
Near-infrared emission bands of TeH and TeD
Journal of Molecular Spectroscopy, 138 (1) :19-28
1989
DOI: 10.1016/0022-2852(89)90094-5
1988: 245.
Fink, Ewald H.; Setzer, Klaus-Dieter; Kottsieper, U.; Ramsay, D. A.; Vervloet, M.
The a1Δ(a2)-X3Σ-(X21) electronic band system of selenium monoxide
Journal of Molecular Spectroscopy, 131 (1) :127-132
1988
DOI: 10.1016/0022-2852(88)90112-9; 244.
Jensen, Per; Bunker, Philip R.
The potential surface and stretching frequencies X~3B1 methylene (CH2) determined from experiment using the Morse oscillator-rigid bender internal dynamics Hamiltonian
The Journal of Chemical Physics, 89 (3) :1327-1332
1988
DOI: 10.1063/1.455184; 243.
Jensen, Per; Bunker, Philip R.
The potential surface and stretching frequencies X\verb=~=\(^{3}\)B\(_{1}\) methylene (CH\(_{2}\)) determined from experiment using the Morse oscillator-rigid bender internal dynamics Hamiltonian
The Journal of Chemical Physics, 89 (3) :1327-1332
1988
DOI: 10.1063/1.455184; 242.
Jensen, Per; Bunker, Philip R.
The potential surface and stretching frequencies X\verb=~=\(^{3}\)B\(_{1}\) methylene (CH\(_{2}\)) determined from experiment using the Morse oscillator-rigid bender internal dynamics Hamiltonian
The Journal of Chemical Physics, 89 (3) :1327-1332
1988
DOI: 10.1063/1.455184; 241.
Benter, Thorsten; Schindler, Ralph N.
Absolute rate coefficients for the reaction of NO\(_{3}\) radicals with simple dienes
Chemical Physics Letters, 145 (1) :67-70
1988
DOI: 10.1016/0009-2614(88)85134-0; 240.
Fink, Ewald H.; Setzer, Klaus-Dieter; Kottsieper, U.; Ramsay, D. A.; Vervloet, M.
The a\(^{1}\)\(\Delta\)(a2)-X\(^{3}\)\(\Sigma\)\(^{-}\)(X\(_{2}\)1) electronic band system of selenium monoxide
Journal of Molecular Spectroscopy, 131 (1) :127-132
1988
DOI: 10.1016/0022-2852(88)90112-9; 239.
Benter, Thorsten; Schindler, Ralph N.
Absolute rate coefficients for the reaction of NO\(_{3}\) radicals with simple dienes
Chemical Physics Letters, 145 (1) :67-70
1988
DOI: 10.1016/0009-2614(88)85134-0; 238.
Weinmüller, E.; Winkler, E.
Path-following Algorithm for Singular Boundary Value Problems
ZAMM, 68 :527--537
1988; 237.
Heilmann, Margareta
Lp-saturation of some modified Bernstein operators
Journal of Approximation Theory, 54 (3) :260-273
1988
ISSN: 0021-9045
DOI: 10.1016/0021-9045(88)90003-2; 236.
Wildt, Jürgen; Bednarek, G.; Fink, Ewald H.; Wayne, Richard P.
Laser excitation of O2(b1Σg+, v'=0,1,2) - rates and channels of energy transfer and quenching
Chemical Physics, 122 (3) :463-470
1988
DOI: 10.1016/0301-0104(88)80027-2; 235.
Wildt, J{ü}rgen; Bednarek, G.; Fink, Ewald H.; Wayne, Richard P.
Laser excitation of O\(_{2}\)(b\(^{1}\)\(\Sigma\)\(_{g}\)\(^{+}\), v'=0,1,2) - rates and channels of energy transfer and quenching
Chemical Physics, 122 (3) :463-470
1988
DOI: 10.1016/0301-0104(88)80027-2; 234.
Wildt, J{ü}rgen; Bednarek, G.; Fink, Ewald H.; Wayne, Richard P.
Laser excitation of O\(_{2}\)(b\(^{1}\)\(\Sigma\)\(_{g}\)\(^{+}\), v'=0,1,2) - rates and channels of energy transfer and quenching
Chemical Physics, 122 (3) :463-470
1988
DOI: 10.1016/0301-0104(88)80027-2; 233.
Czech, C. M.; Kling, H.-W.; Hartkamp, H.
Kontinuierliche Derivatisierung von schwerflüchtigen Wasserinhaltsstoffen durch Periodat-Oxidation in Verbindung mit dem Contistrip-Verfahren
Fresenius' Journal of Analytical Chemistry, 332 (4) :341--344
1988; 232.
Jensen, Per
Hamiltonians for the internal dynamics of triatomic molecules
Journal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics, 84 (9) :1315-1339
1988
DOI: 10.1039/F29888401315; 231.
Jensen, Per
Hamiltonians for the internal dynamics of triatomic molecules
Journal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics, 84 (9) :1315-1339
1988
DOI: 10.1039/F29888401315; 230.
Jensen, Per
Hamiltonians for the internal dynamics of triatomic molecules
Journal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics, 84 (9) :1315-1339
1988
DOI: 10.1039/F29888401315; 229.
[german] Tausch, Michael W.; Paterkiewicz, D.
Fluoreszenz und Phosphoreszenz
Praxis der Naturwissenschaften (Chemie), 36 :14
1988

Computational Magnetics

Research Questions

Cooperation

Former and ongoing projects

Publications

253.

252.

251.

250.

249.

248.

247.

246.

245.

244.

243.

242.

241.

240.

239.

238.

237.

236.

235.

234.

233.

232.

231.

230.

229.