Coordinated Tuning of PSS and SSSC–POD Controller Using Ant Colony Optimization for Power Oscillation Damping

Abstract

Low-frequency electromechanical oscillations can degrade the stability of interconnected power systems if not properly damped. Power System Stabilizers (PSS) and Power Oscillation Damping (POD) controllers in FACTS devices are widely used to improve system damping. This paper proposes a coordinated tuning strategy for a PSS and a Static Synchronous Series Compensator (SSSC) with a POD controller. The problem is formulated as a multi-objective optimization that minimizes tie-line power deviations, speed and power angle deviations. Ant Colony Optimization for Continuous Domains (ACOR) is applied to determine optimal controller parameters due to its effectiveness in nonlinear continuous search spaces. Simulation studies on a two-area test system under three-phase fault conditions demonstrate that the ACOR-tuned controllers significantly reduce oscillation amplitude and enhance damping, and improve transient stability compared to baseline gains. The results confirm the potential of metaheuristic optimization for coordinated FACTS-based damping control.