Design of decentralized power system stabilizer for multi-machine power system using periodic output feedback technique

Power System Stabilizer (PSS) are added to excitation system to enhance the damping of electric power system during low frequency oscillations. Design of decentralized PSS for 4 machines with 10 buses using periodic output feedback is proposed. The nonlinear model of multi-machine system is linearized and linear state space model is obtained. An output injection gain is obtained using LQR technique. A decentralized periodic output feedback gain which realizes this output injection gain is obtained using LMI approach. This method doesn't require state of the system for feedback. It uses only the output for feedback. Thus it is easily implementable.