Fuzzy Applications to Single Machine Power System Stabilizers

Power system stabilizers (PSSs) are added to excitation system to enhance the damping during low frequency oscillations. 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 the stability enhancement, speed deviation (Δω) and acceleration (Δπ) of the rotor of synchronous generator of Kota Thermal were taken as the input to the fuzzy logic controller. These variables take significant effects on damping on damping of the generator shaft mechanical oscillations. The stabilizing signals were computed using the fuzzy membership functions depending on these variables. The performance of the fuzzy PSS is compared with the conventional power system stabilizer (CPSS). The simulations were tested under different operating conditions and change in reference voltage also tested with different membership functions. The simulation results are quite encouraging and satisfactory