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



2014

2975.

Ehrhardt, Matthias; Sánchez, Lucas Jódar; Villanueva Micó, Rafael Jacinto
Advanced computational engineering
2014

2974.

Ehrhardt, Matthias; Sánchez, Lucas Jódar; Villanueva Micó, Rafael Jacinto
Advanced computational engineering
International Journal of Computer Mathematics, 91 (1) :1–3
2014
Herausgeber: Taylor & Francis

2973.

Ehrhardt, Matthias; Sánchez, Lucas Jódar; Villanueva Micó, Rafael Jacinto
Advanced computational engineering
International Journal of Computer Mathematics, 91 (1) :1–3
2014
Herausgeber: Taylor & Francis

2972.


Advanced Mathematical Models and Numerical Techniques for Multiband Effective Mass Approximations
In M. Ehrhardt and Th. Koprucki, Editor, Band 94 aus LNCSE
Herausgeber: Springer, Heidelberg
2014

2971.

Jacob, Birgit; Partington, Jonathan R.; Pott, Sandra
Applications of {L}aplace-{C}arleson embeddings to admissibility and controllability
SIAM J. Control Optim., 52 (2) :1299--1313
2014

2970.

Jacob, Birgit; Partington, Jonathan R.; Pott, Sandra
Applications of Laplace-Carleson embeddings to admissibility and controllability
SIAM J. Control Optim., 52 (2) :1299--1313
2014

2969.

Klee, Sonja; Derpmann, Valerie; Wissdorf, Walter; Klopotowski, Sebastian; Kersten, Hendrik; Brockmann, Klaus Josef; Benter, Thorsten; Albrecht, Sascha; Bruins, Andries P.; Dousty, Faezeh; Kauppila, Tiina J.; Kostiainen, Risto; O'Brien, Rob; Robb, Damon B.; Syage, Jack A.
Are Clusters Important in Understanding the Mechanisms in Atmospheric Pressure Ionization? Part 1: Reagent Ion Generation and Chemical Control of Ion Populations
Journal of The American Society for Mass Spectrometry, 25 (8) :1310-1321
2014

2968.

Klee, Sonja; Derpmann, Valerie; Wissdorf, Walter; Klopotowski, Sebastian; Kersten, Hendrik; Brockmann, Klaus Josef; Benter, Thorsten; Albrecht, Sascha; Bruins, Andries P.; Dousty, Faezeh; Kauppila, Tiina J.; Kostiainen, Risto; O'Brien, Rob; Robb, Damon B.; Syage, Jack A.
Are Clusters Important in Understanding the Mechanisms in Atmospheric Pressure Ionization? Part 1: Reagent Ion Generation and Chemical Control of Ion Populations
Journal of The American Society for Mass Spectrometry, 25 (8) :1310-1321
2014

2967.

Klee, Sonja; Derpmann, Valerie; Wißdorf, Walter; Klopotowski, Sebastian; Kersten, Hendrik; Brockmann, Klaus Josef; Benter, Thorsten; Albrecht, Sascha; Bruins, Andries P.; Dousty, Faezeh; Kauppila, Tiina J.; Kostiainen, Risto; O'Brien, Rob; Robb, Damon B.; Syage, Jack A.
Are Clusters Important in Understanding the Mechanisms in Atmospheric Pressure Ionization? Part 1: Reagent Ion Generation and Chemical Control of Ion Populations
Journal of The American Society for Mass Spectrometry, 25 (8) :1310-1321
2014

2966.

Linnhoff, Luisa
Biodiversität und Naturverjüngung auf Kyrill-Sturmflächen
2014

2965.

Ankirchner, Stefan; Jeanblanc, Monique; Kruse, Thomas
BSDEs with singular terminal condition and a control problem with constraints
SIAM Journal on Control and Optimization, 52 (2) :893--913
2014
Herausgeber: SIAM

2964.

Ankirchner, Stefan; Jeanblanc, Monique; Kruse, Thomas
BSDEs with singular terminal condition and a control problem with constraints
SIAM Journal on Control and Optimization, 52 (2) :893–913
2014
Herausgeber: Society for Industrial and Applied Mathematics

2963.

Klee, Sonja; Thinius, Marco; Brockmann, Klaus Josef; Benter, Thorsten
Capillary atmospheric pressure chemical ionization using liquid point electrodes
Rapid Communications in Mass Spectrometry, 28 (14) :1591-1600
2014

2962.

Klee, Sonja; Thinius, Marco; Brockmann, Klaus Josef; Benter, Thorsten
Capillary atmospheric pressure chemical ionization using liquid point electrodes
Rapid Communications in Mass Spectrometry, 28 (14) :1591-1600
2014

2961.

Klee, Sonja; Thinius, Marco; Brockmann, Klaus Josef; Benter, Thorsten
Capillary atmospheric pressure chemical ionization using liquid point electrodes
Rapid Communications in Mass Spectrometry, 28 (14) :1591-1600
2014

2960.

Derpmann, Valerie; Müller, David; Bejan, Iustinian; Sonderfeld, Hannah; Wilberscheid, Sonja; Koppmann, Ralf; Brockmann, Klaus Josef; Benter, Thorsten
Capillary Atmospheric Pressure Electron Capture Ionization (cAPECI): A Highly Efficient Ionization Method for Nitroaromatic Compounds
Journal of The American Society for Mass Spectrometry, 25 (3) :329-342
2014

2959.

Derpmann, Valerie; M{ü}ller, David; Bejan, Iustinian; Sonderfeld, Hannah; Wilberscheid, Sonja; Koppmann, Ralf; Brockmann, Klaus Josef; Benter, Thorsten
Capillary Atmospheric Pressure Electron Capture Ionization (cAPECI): A Highly Efficient Ionization Method for Nitroaromatic Compounds
Journal of The American Society for Mass Spectrometry, 25 (3) :329-342
2014

2958.

Derpmann, Valerie; M{ü}ller, David; Bejan, Iustinian; Sonderfeld, Hannah; Wilberscheid, Sonja; Koppmann, Ralf; Brockmann, Klaus Josef; Benter, Thorsten
Capillary Atmospheric Pressure Electron Capture Ionization (cAPECI): A Highly Efficient Ionization Method for Nitroaromatic Compounds
Journal of The American Society for Mass Spectrometry, 25 (3) :329-342
2014

2957.

Bartel, Andreas; Ehrhardt, Matthias
Characteristic boundary conditions in the lattice Boltzmann method for fluid and gas dynamics
Journal of Computational and Applied Mathematics, 262 :51–61
2014
Herausgeber: North-Holland

2956.

Bartel, Andreas; Ehrhardt, Matthias
Characteristic boundary conditions in the lattice Boltzmann method for fluid and gas dynamics
Journal of Computational and Applied Mathematics, 262 :51–61
2014
Herausgeber: North-Holland

2955.

Tausch, Michael W.; Wachtendonk, M.; Bohrmann-Linde, Claudia; Krees, Simone; Buric, Ralf; Krollmann, Patrick; Schmitz, Wolfgang; Schulze, Ilona; Wambach, Heinz
CHEMIE 2000+ Lehrerband zur Einführungsphase
Herausgeber: C.C.Buchner, Bamberg
2014

2954.

Tausch, Michael W.; Wachtendonk, M.; Bohrmann-Linde, Claudia; Krees, Simone
CHEMIE 2000+ Qualifikationsphase
Herausgeber: C.C.Buchner, Bamberg
2014

2953.

Tausch, Michael W.; Flint, Alfred
Chemiedidaktik 2013 - Experimentell konzeptionelle Forschung in der Chemiedidaktik
Nachrichten aus der Chemie, 62 (3) :359
2014
Herausgeber: Wiley

2952.

Ehrhardt, Matthias
Classical and quasi-newton methods for a meteorological parameters prediction boundary value problem
Applied Mathematics & Information Sciences, 8 (6) :2683–2693
2014
Herausgeber: Natural Sciences Publishing

2951.

Ehrhardt, Matthias
Classical and quasi-newton methods for a meteorological parameters prediction boundary value problem
Applied Mathematics & Information Sciences, 8 (6) :2683–2693
2014
Herausgeber: Natural Sciences Publishing