Inter-area power oscillation control in a multi-machine power system by coordinating the PSS and UPFC operation

The power system stability has always been one of the most significant and controversial debates among researchers and electric power engineers. The synchronous generators producing the most electrical energy in current power systems all around worlds must operate under safe conditions in terms of short circuit and open circuit faults occurrence to prevent the network instability. The Flexible Alternating Current Transmission System (FACTS) devices have been introduced to improve the power quality as well as loss reduction in the power systems. In this paper, a Unified Power Flow Controller (UPFC) is placed in the power system to improve the power quality. In addition, the Ant Colony Optimization (ACO) approach finds suitable proportional-integral coefficients of the Power System Stabilizers (PSSs) and UPFC controller parameters to coordinate them in order to improve power system stability. The simulation results demonstrate the robustness and effectiveness of the coordination and controller design method in damping inter-area oscillations.