Improving power system stability using a fuzzy logic control

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, two approaches to design Fuzzy Logic Power System Stabilizers (FLPSS) as follows: 1-FLC1 has Speed deviation and power angle as its input Δω and ΔPa. 2-FLC2 has Speed deviation and Acceleration as its input Δω and Δδ. The performance of these two approaches is compared and is compared with the system without PSS. The stabilizing signals were computed using the fuzzy membership functions depending on these variables. The simulations were tested under different operating conditions, also tested with different membership functions. The simulation results are quite encouraging and satisfactory.