An optimal fuzzy PID power system stabilizer for single machine infinite bus system

This study represents a design of an optimal fuzzy Proportional Integral Derivative (PID) power system stabilizer for single machine infinite bus power system. The aim of the control is to enhance the stability and to improve the dynamic response of the single machine infinite bus power system operating at different conditions. Speed deviation and acceleration of synchronous machine are chosen as the input signals to the fuzzy controllers. These variables take significant effects on damping of the generator shaft mechanical oscillations. The three parameters of PID controller are computed using the fuzzy membership functions depending on these variables. The inference mechanism of the fuzzy PID controller is represented by three (7x7) decision tables. The controller is simulated for implementing of the study. The simulations are performed under different operating conditions. Also a mechanical disturbance which has square wave waveform and 0,5 magnitude is injected to system from Tm input point during 0,5 s. Simulation results also are compared with conventional power system stabilizer, PID power system stabilizer and fuzzy power system stabilizer in order to show effectiveness of the proposed controller. Key Words: Power system stabilizer, fuzzy PID controller, single-machine infinite-bus model, fuzzy logic