Quasi-stationary AC analysis by coupling transient and phasor description

Investigation of heterogeneous systems ("multi-nature systems" or "multi-domain systems") by simulating long time periods requires effective methods. If only sinusoidal quantities with fixed frequencies occur in one of the involved domains then phasor analysis can be used to describe steady-state behaviour of this part of the heterogeneous system. But an analysis of only steady states ist seldom of interest. Rather, it would be advantageous to investigade different steady states in form of a sequence and their interaction with the other parts of the complete system. In these cases, a coupling of phasor analysis and transient analysis is desirable. In the present paper, modelling of electrical AC systems using the well-known phasor method is shortly repeated. The main focus of the paper is the coupling of such phasor domain-based models with transient models of other domains (e.g. mechanical). Some simulation results of electric machines considered as electromechanical systems (i.e. typical instances of a multi-domain system) are given.