Design of PSS for SMIB system using robust fast output sampling feedback technique

The Power System Stabilizers (PSS) are added to excitation systems to enhance the damping during low frequency oscillations. In this paper, the design of PSS for single machine connected to an infinite bus (SMIB) using fast output sampling feedback is proposed. The nonlinear model of a machine is linearised at different operating points and 5 linear plant models are obtained. For all of these plants a single stabilizing state feedback gain, F is obtained. A robust fast output sampling feedback gain which realizes this state feedback gain is obtained using linear matrix inequalities approach. This method does not require state of the system for feedback and is easily implementable. This robust fast output sampling control is applied to non-linear plant model of one machine at different operating (equilibrium) points. The performance of the robust fast output sampling (FOS) feedback is compared with the system response without PSS and with conventional PSS (CPSS). The simulation results obtained from the plant over a wide range of operating conditions indicate the improved performance of FOS based PSS over the conventional power system stabilizer (CPSS). This method gives very good results for the design of PSS.