IMPLEMENTATION OF FUZZY LOGIC IN POWER SYSTEM STABILIZER TO IMPROVE SYSTEM DAMPING

Abstract

The use of power system stabilizers has become very common in operation of large electric power systems. However, it was very difficult to design a stabilizer that could present good performance in all operating points of electric power systems. In an attempt to cover a wide range of operating conditions, Fuzzy logic control has been suggested as a possible solution to overcome this problem, by using linguist information and avoiding a complex system mathematical model. In this thesis, a systematic approach to fuzzy logic control design is proposed. This paper presents a study of fuzzy logic power system stabilizer for stability enhancement of a single machine infinite bus system. In order to accomplish the stability enhancement, speed deviation ω&ΔωΔ and acceleration of the rotor synchronous generator were taken as the inputs 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-7 is utilized in implementing the study. The performance of the fuzzy logic power system stabilizer iss compared with the conventional power system stabilizer and without power system stabilizer. Also the scaling parameters of proposed fuzzy logic controller are determined offline using genetic algorithm. . iii