A unified model for the analysis of FACTS devices in damping power system oscillations. II. Multi-machine power systems

This paper establishes a unified model of a multi-machine power system installed with three types of FACTS-based stabilizer, which is an extension of the work presented in part I of this paper. The application of the unified model is demonstrated by the damping torque analysis of multi-machine power systems, the conclusion of which is that the damping function of FACTS-based stabilizers can be interpreted as an addition of damping torque on every generator in the system. Three indices are proposed for the selection of the best installing location of FACTS-based stabilizers in multi-machine power systems, the use of which depends on the extent of available system information.