An investigation on the use of power system stabilizers for damping inter-area oscillations in longitudinal power systems

This paper presents the progress of an investigation on the use of power system stabilizers (PSSs) to enhance the damping of low-frequency inter-area modes in longitudinal power systems. A dynamic model of the Mexican Interconnected System (MIS) is adopted to evaluate the potential for small signal stability improvement by means of PSSs. Power oscillation flow studies, transfer function residues and controllability and observability characteristics are used to understand the nature of oscillation patterns, mode identification and PSSs siting. It is shown that PSSs can significantly enhance the damping of modal oscillations, especially under high stress conditions.