On Transient Stability of Multi–Machine Power Systems: A 'Globally' Convergent Controller for Structure–Preserving Models

The design of excitation controllers to improve transient stabilization of power systems is a topic of renewed interest in the control community. Existence of a state– feedback stabilizing law for multi–machine aggregated reduced network models has recently been established. In this paper we extend this result in two directions: first, in contrast with aggregated models, we consider the more natural and widely popular structure–preserving models (SPM) that preserve the identity of the network components and allow for a more realistic treatment of the loads. Second, we explicitly compute a control law that, under a detectability assumption, ensures that all trajectories converge to the desired equilibrium point, provided that they start and remain in the region where the model makes physical sense.