Design of decentralized power system stabilizers for multimachine power system using model reduction and fast output sampling techniques

Power system stabilizers (PSS) are added to excitation systems to enhance the damping during low frequency oscillations. In this paper, the design of decentralized PSS for 10 machines with 39 buses using fast output sampling feedback via reduced order model is proposed. The nonlinear model of multi-machine system is linearized at a particular operating point and a linear model is obtained. Using model reduction technique, lower order model is obtained from the higher order model and for this reduced model a stabilizing state feedback gain is obtained. Using aggregation technique, state feedback gain is obtained for the higher order model. A decentralized fast output sampling feedback gain which realizes this state feedback gain is obtained using LMI approach. This method does not require state of the system for feedback and is easily implementable. This decentralized fast output sampling control via reduced order model is applied to non-linear plant model of the multi-machine. This method gives very good results for the design of power system stabilizers.