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

1990

292.

Tausch, Michael W.; Deissenberger, H.; Fischer, W.; Hoffmann, W.; Jakob, O.; Riedl, A.; Schallies, M.; Wachtendonk, M.
Lehrerband mit didaktischen Hinweisen und Lösungen der Aufgaben zu STOFF UND FORMEL II, Lehrbuch für die S II (Grundkurse)
Herausgeber: C. C. Buchner, Bamberg
1990

291.

Tausch, Michael W.; Deissenberger, H.; Fischer, W.; Hoffmann, W.; Jakob, O.; Riedl, A.; Schallies, M.; Wachtendonk, M.
STOFF UND FORMEL II, Lehrbuch für die S II (Grundkurse), 325 Seiten
Herausgeber: C. C. Buchner, Bamberg
1990

290.


Technische Universität Berlin Wintersemester 06/07 Fakultät II--Institut für Mathematik
SIAM J. Appl. Math, 50 :1442--1456
1990
1989

289.

Bunker, Philip R.; Jensen, Per; Karpfen, Alfred; Lischka, Hans
A theoretical calculation of the rotation-vibration energies for lithium hydroxide, LiOH
Journal of Molecular Spectroscopy, 135 (1) :89-104
1989

DOI: 10.1016/0022-2852(89)90357-3

288.

Bunker, Philip R.; Jensen, Per; Karpfen, Alfred; Lischka, Hans
A theoretical calculation of the rotation-vibration energies for lithium hydroxide, LiOH
Journal of Molecular Spectroscopy, 135 (1) :89-104
1989

DOI: 10.1016/0022-2852(89)90357-3

287.

Bunker, Philip R.; Jensen, Per; Karpfen, Alfred; Lischka, Hans
A theoretical calculation of the rotation-vibration energies for lithium hydroxide, LiOH
Journal of Molecular Spectroscopy, 135 (1) :89-104
1989

DOI: 10.1016/0022-2852(89)90357-3

286.

Comeau, Donald C.; Shavitt, Isaiah; Jensen, Per; Bunker, Philip R.
An ab initio determination of the potential-energy surfaces and rotation-vibration energy levels of methylene in the lowest triplet and singlet states and the singlet-triplet splitting
The Journal of Chemical Physics, 90 (11) :6491-6500
1989

DOI: 10.1063/1.456315

285.

Comeau, Donald C.; Shavitt, Isaiah; Jensen, Per; Bunker, Philip R.
An ab initio determination of the potential-energy surfaces and rotation-vibration energy levels of methylene in the lowest triplet and singlet states and the singlet-triplet splitting
The Journal of Chemical Physics, 90 (11) :6491-6500
1989

DOI: 10.1063/1.456315

284.

Comeau, Donald C.; Shavitt, Isaiah; Jensen, Per; Bunker, Philip R.
An ab initio determination of the potential-energy surfaces and rotation-vibration energy levels of methylene in the lowest triplet and singlet states and the singlet-triplet splitting
The Journal of Chemical Physics, 90 (11) :6491-6500
1989

DOI: 10.1063/1.456315

283.

Civis, S.; Blom, C. E.; Jensen, Per
Diode laser infrared spectra and potential energy curve for SH\(^{+}\)
Journal of Molecular Spectroscopy, 138 (1) :69-78
1989

DOI: 10.1016/0022-2852(89)90099-4

282.

Civis, S.; Blom, C. E.; Jensen, Per
Diode laser infrared spectra and potential energy curve for SH\(^{+}\)
Journal of Molecular Spectroscopy, 138 (1) :69-78
1989

DOI: 10.1016/0022-2852(89)90099-4

281.

Civis, S.; Blom, C. E.; Jensen, Per
Diode laser infrared spectra and potential energy curve for SH+
Journal of Molecular Spectroscopy, 138 (1) :69-78
1989

DOI: 10.1016/0022-2852(89)90099-4

280.

Heilmann, Margareta
Direct and converse results for operators of Baskakov-Durrmeyer type
Approximation Theory Appl., 5 (1) :105-127
1989

DOI: 10.1007/BF02836120

279.

Heilmann, Margareta; Müller, Manfred
Direct and converse results on weighted simultaneous approximation by the method of operators of Baskakov-Durrmeyer type
Results in Mathematics, 16 (3-4) :228-242
1989

DOI: 10.1007/BF03322474

278.

Tausch, Michael W.; Wöhrle, D.
Katalytische Wasserphotolyse
Praxis der Naturwissenschaften (Chemie), 38 :46
1989

277.

Tausch, Michael W.
Kritische Überlegungen zur Teilchenzahl als eigenständige Größe im Größenkalkül
Der mathematische und naturwissenschaftliche Unterricht (MNU), 42 :438
1989

276.

Tausch, Michael W.; Wachtendonk, M.
Lehrerband mit didaktischen Hinweisen und Lösungen der Aufgaben zu STOFF-FORMEL-UMWELT, BAND 1: CHEMISCHE GLEICHGEWICHTE - ELEKTROCHEMIE, Lehrbuch für die S II (Grund- und Leistungskurse), 172 Seiten
Herausgeber: C. C. Buchner, Bamberg
1989

275.

Bauer, W.; Engelhardt, B.; Wiesen, Peter; Becker, Karl Heinz
Lifetime measurements of GeH and CH in the A\(^{2}\)\(\Delta\), v'=0 state by laser-induced fluorescence
Chemical Physics Letters, 158 (3-4) :321-324
1989

DOI: 10.1016/0009-2614(89)87344-0

274.

Bauer, W.; Engelhardt, B.; Wiesen, Peter; Becker, Karl Heinz
Lifetime measurements of GeH and CH in the A\(^{2}\)\(\Delta\), v'=0 state by laser-induced fluorescence
Chemical Physics Letters, 158 (3-4) :321-324
1989

DOI: 10.1016/0009-2614(89)87344-0

273.

Bauer, W.; Engelhardt, B.; Wiesen, Peter; Becker, Karl Heinz
Lifetime measurements of GeH and CH in the A2Δ, v'=0 state by laser-induced fluorescence
Chemical Physics Letters, 158 (3-4) :321-324
1989

DOI: 10.1016/0009-2614(89)87344-0

272.

Becker, Karl Heinz; Wiesen, Peter
Measurements on the CH*(A\(^{2}\)\(\Delta\) → X\(^{2}\)\(\Pi\)) Chemiluminescence in the C\(_{2}\)H\(_{2}\) + O Flame and Quenching Rate Constants for Different Reactants at 297 K
Zeitschrift für Physikalische Chemie, 161 (Part_1_2) :131-144
1989

DOI: 10.1524/zpch.1989.161.Part_1_2.131

271.

Becker, Karl Heinz; Wiesen, Peter
Measurements on the CH*(A\(^{2}\)\(\Delta\) → X\(^{2}\)\(\Pi\)) Chemiluminescence in the C\(_{2}\)H\(_{2}\) + O Flame and Quenching Rate Constants for Different Reactants at 297 K
Zeitschrift für Physikalische Chemie, 161 (Part_1_2) :131-144
1989

DOI: 10.1524/zpch.1989.161.Part_1_2.131

270.

Becker, Karl Heinz; Wiesen, Peter
Measurements on the CH*(A2Δ → X2Π) Chemiluminescence in the C2H2 + O Flame and Quenching Rate Constants for Different Reactants at 297 K
Zeitschrift für Physikalische Chemie, 161 (Part_1_2) :131-144
1989

DOI: 10.1524/zpch.1989.161.Part_1_2.131

269.

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

268.

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