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

1986

153.

Jensen, Per; Bunker, Philip R.
The nonrigid bender Hamiltonian using an alternative perturbation technique
Journal of Molecular Spectroscopy, 118 (1) :18-39
1986

DOI: 10.1016/0022-2852(86)90220-1

152.

Jensen, Per; Bunker, Philip R.
The nonrigid bender Hamiltonian using an alternative perturbation technique
Journal of Molecular Spectroscopy, 118 (1) :18-39
1986

DOI: 10.1016/0022-2852(86)90220-1

151.

Jensen, Per; Bunker, Philip R.
The nonrigid bender Hamiltonian using an alternative perturbation technique
Journal of Molecular Spectroscopy, 118 (1) :18-39
1986

DOI: 10.1016/0022-2852(86)90220-1

150.

Jensen, Per; Johns, John W. C.
The infrared spectrum of carbon suboxide in the ν6 fundamental region: Experimental observation and semirigid bender analysis
Journal of Molecular Spectroscopy, 118 (1) :248-266
1986

DOI: 10.1016/0022-2852(86)90239-0

149.

Jensen, Per; Winnewisser, Manfred
Prediction of higher inversion energy levels for isocyanamide H\(_{2}\)NNC
Collection of Czechoslovak Chemical Communications, 51 (7) :1373-1381
1986
Herausgeber: Institute of Organic Chemistry and Biochemistry AS CR, v.v.i.

DOI: 10.1135/cccc19861373

148.

Fink, Ewald H.; Kruse, H.; Ramsay, D. A.; Vervloet, M.
An electric quadrupole transition: the emission system of oxygen
Canadian Journal of Physics, 64 (3) :242-245
1986
Herausgeber: NRC Research Press Ottawa, Canada

DOI: 10.1139/p86-044

147.

Jensen, Per; Johns, John W. C.
The infrared spectrum of carbon suboxide in the \(\nu\)\(_{6}\) fundamental region: Experimental observation and semirigid bender analysis
Journal of Molecular Spectroscopy, 118 (1) :248-266
1986

DOI: 10.1016/0022-2852(86)90239-0

146.

Beardsworth, R.; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
Ab initio rotation-vibration energies of HOC+ calculated using the nonrigid bender Hamiltonian
Journal of Molecular Spectroscopy, 118 (1) :40-49
1986

DOI: 10.1016/0022-2852(86)90221-3

145.

Fink, Ewald H.; Kruse, H.; Ramsay, D. A.; Vervloet, M.
An electric quadrupole transition: the emission system of oxygen
Canadian Journal of Physics, 64 (3) :242-245
1986
Herausgeber: NRC Research Press Ottawa, Canada

DOI: 10.1139/p86-044

144.

Beardsworth, R.; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
Ab initio rotation-vibration energies of HOC\(^{+}\) calculated using the nonrigid bender Hamiltonian
Journal of Molecular Spectroscopy, 118 (1) :40-49
1986

DOI: 10.1016/0022-2852(86)90221-3

143.

Beardsworth, R.; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
Ab initio rotation-vibration energies of HOC\(^{+}\) calculated using the nonrigid bender Hamiltonian
Journal of Molecular Spectroscopy, 118 (1) :40-49
1986

DOI: 10.1016/0022-2852(86)90221-3

142.

Jensen, Per; Johns, John W. C.
The infrared spectrum of carbon suboxide in the \(\nu\)\(_{6}\) fundamental region: Experimental observation and semirigid bender analysis
Journal of Molecular Spectroscopy, 118 (1) :248-266
1986

DOI: 10.1016/0022-2852(86)90239-0

141.

Kraemer, Wolfgang P.; Roos, B. O.; Bunker, Philip R.; Jensen, Per
An ab initio calculation of the rotation-vibration energies of the state of CCH using the nonrigid bender Hamiltonian
Journal of Molecular Spectroscopy, 120 (1) :236-238
1986

DOI: 10.1016/0022-2852(86)90085-8

140.

Kraemer, Wolfgang P.; Roos, B. O.; Bunker, Philip R.; Jensen, Per
An ab initio calculation of the rotation-vibration energies of the state of CCH using the nonrigid bender Hamiltonian
Journal of Molecular Spectroscopy, 120 (1) :236-238
1986

DOI: 10.1016/0022-2852(86)90085-8

139.

Fink, Ewald H.; Kruse, H.; Ramsay, D. A.; Vervloet, M.
An electric quadrupole transition: the emission system of oxygen
Canadian Journal of Physics, 64 (3) :242-245
1986
Herausgeber: NRC Research Press Ottawa, Canada

DOI: 10.1139/p86-044

138.

Kraemer, Wolfgang P.; Roos, B. O.; Bunker, Philip R.; Jensen, Per
An ab initio calculation of the rotation-vibration energies of the state of CCH using the nonrigid bender Hamiltonian
Journal of Molecular Spectroscopy, 120 (1) :236-238
1986

DOI: 10.1016/0022-2852(86)90085-8

1985

137.

Phillips, R.A.; Buenker, Robert J.; Beardsworth, R.; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
An ab initio study of the rotation-vibration energy levels of GeH\(_{2}\) in the a\verb=~=\(^{3}\)B\(_{1}\) state
Chemical Physics Letters, 118 (1) :60-63
1985

DOI: 10.1016/0009-2614(85)85266-0

136.

Holstein, K. J.; Fink, Ewald H.; Wildt, J{ü}rgen; Zabel, Friedhelm
A\verb=~=\(^{2}\)A' → X\verb=~=\(^{2}\)A'' emission spectrum of the HS\(_{2}\) radical
Chemical Physics Letters, 113 (1) :1-7
1985

DOI: 10.1016/0009-2614(85)85001-6

135.

Holstein, K. J.; Fink, Ewald H.; Wildt, J{ü}rgen; Zabel, Friedhelm
A\verb=~=\(^{2}\)A' → X\verb=~=\(^{2}\)A'' emission spectrum of the HS\(_{2}\) radical
Chemical Physics Letters, 113 (1) :1-7
1985

DOI: 10.1016/0009-2614(85)85001-6

134.

Holstein, K. J.; Fink, Ewald H.; Wildt, Jürgen; Zabel, Friedhelm
A~2A' → X~2A" emission spectrum of the HS2 radical
Chemical Physics Letters, 113 (1) :1-7
1985

DOI: 10.1016/0009-2614(85)85001-6

133.

Tausch, Michael W.
Aktivierungsenergie - was ist das?
Praxis der Naturwissenschaften (Chemie), 34 :33
1985

132.

Kling, H.-W.; Hartkamp, H.; Buchholz, N.
Matrixunabhängige kontinuierliche Dampfraum-Gas-Chromatographie
Fresenius' Journal of Analytical Chemistry, 320 (4) :341--346
1985

131.

Phillips, R.A.; Buenker, Robert J.; Beardsworth, R.; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
An ab initio study of the rotation-vibration energy levels of GeH\(_{2}\) in the a\verb=~=\(^{3}\)B\(_{1}\) state
Chemical Physics Letters, 118 (1) :60-63
1985

DOI: 10.1016/0009-2614(85)85266-0

130.

Phillips, R.A.; Buenker, Robert J.; Beardsworth, R.; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
An ab initio study of the rotation-vibration energy levels of GeH2 in the a~3B1 state
Chemical Physics Letters, 118 (1) :60-63
1985

DOI: 10.1016/0009-2614(85)85266-0

129.

Winkler, R.
Path-following for two-point boundary value problems
, Seminarbericht 78 der Sektion MathematikBand78
Humboldt-Universität zu Berlin
1985