Transient fault responses of a synchronous generator with a coupled circuit model

Harmonic content, magnetic saturation and simulation time can be an issue for the analysis of steady-state and transient behavior of electrical machines. Carrying the simulations with a finite-elements software results in long simulation time. To reduce the simulation time, this paper proposes a fast modelling method based on a coupled circuit whose magnetic couplings are identified with magnetostatic 2D FE simulations. This method provides an accurate spatial modelling. The magnetic couplings for each discrete rotor position are stored in a table. We show that a simple interpolation method can be used for the inductance estimation at any rotor position with a variable-step solver. The impact of the angular discretization on the waveforms is analyzed. We propose also a simple method to consider the saturation in the coupled-circuit. The performance of this model is analyzed for the steady-state and transient current responses of a synchronous generator with high field current.