A new coordinated control scheme of PSS and FACT devices for improving power system oscillations in multi-machine system

This paper presents a new coordinated control scheme based on wide-area signals to coordinate local controllers The coordinated controller transmits the supplementary signals to the local controllers. The proposed scheme uses the energy function based on Lyapunov´s stability theory for modeling a coordinated controller. In this study, the coordinated controller which is installed at system control center utilizes remote measurements and compensates the interactions between the local controllers. When the coordinated controller is implemented, it provides an additional oscillation damping and also improves the global stability of the power system. A two-area power system which is installed with PSS and SVC is selected to simulate and investigate in this study. The simulation results in different operation conditions and contingencies indicate that implementation of coordinated control scheme can heighten the efficiency of power system and can enhance power oscillation damping for multi-machine power system. Moreover, this scheme can be used to improve the stability of the large power system with multi local controllers.