Decentralized Synergistic Control of Multi-Machine Power System Using Power System Stabilizer

Many researchers have proposed small signal analysis methods and numerous power system stabilizers designed by system linearization. In these approaches, it is assumed that disturbances are so small and the linear approximation error of a nonlinear power system remains in an acceptable range. However, the approximation can restrict the validity of linearized models to a neighborhood of equilibrium points. In this paper, in order to reduce the concerns related to the linearization of the power system and damping of electromechanical oscillations, the synergistic nonlinear control method has been used. In addition, a decentralized control strategy was proposed for the use of power system stabilizers in multi-machine power systems. The relation between generators was modelled as a function of variables and its effects on a single machine connected to an infinite bus power system were examined under various disturbances. Also, three test systems were used to verify the efficiency of the proposed decentralized synergetic method. The simulation results showed that the proposed power system stabilizer was more effective than other stabilizers such as a multi-band power system stabilizer in local and inter-area mode oscillations and under different disturbances.