Indirectly coupling time-stepping techniques for electro-magnetic systems using quasi Newton-Raphson solvers and on-line field calculations

The paper describes indirectly coupling time-stepping techniques using quasi Newton-Raphson solvers and on-line field calculations. Due to the quasi Newton-Raphson solvers the electric and magnetic subsystems are strongly coupled and the number of independent currents exciting the magnetic field is not limited. Compared to indirectly coupling time-stepping techniques using state-space models and on-line field calculations, the number of field calculations can be reduced significantly. As a first test, these indirectly coupling time-stepping techniques are used to simulate the dynamic response of a ring-core transformer. The simulation results are in good accordance with the measurements