Study of fuzzy logic power system stabilizer

This paper presents a study of fuzzy logic power system stabilizer (PSS) for stability enhancement of a single machine power system. In order to accomplish a stability enhancement., speed deviation (Δω) and acceleration (Δω~) of the rotor synchronous generator were taken as the input to the fuzzy logic controller. These variables take significant effects on damping the generator shaft mechanical oscillations. The stabilizing signals were computed using the fuzzy membership function depending on these variables. Simulink Block Design and Matlab 5.3 were utilized in implementing the study. The performance of the fuzzy logic power system stabilizer was compared with the conventional power system stabilizer and without power system stabilizer. The simulations were tested under different types of conditions; the steady state operation, three phase to ground fault, mechanical power input changes, generator loading and reference voltage (V_ref) step changes.