Power system oscillation damping by intelligent power system stabilizer

Power Systems are inherently non-linear systems that are frequently subjected to various disturbances causing oscillations at low frequencies that may lead to instability. Generators are usually provided with power system stabilizers minimize the effect of these oscillations. The objective of this paper is find the optimal parameters for a conventional “lead-lag compensator based Power System Stabilizer (PSS)” for a system comprising of a “generator connected to an infinite bus” and containing a ST1A type excitation system. The tuning of the parameters of the “Power System Stabilizer” is accomplished using the “Particle Swarm Optimization (PSO)” algorithm. In this paper, a Fuzzy Power System Stabilizer (FPSS) where the optimal values of the parameters of the FPSS are decided using the PSO algorithm is also designed. The Particle Swarm Optimization based conventional PSS and the “Particle Swarm Optimization based Fuzzy PSS” are also incorporated in a system containing multiple machines to check the system responses under different loading conditions and faults of different types. The simulation results clearly prove the efficiency of the PSO based conventional and fuzzy power system stabilizers in damping the low frequency speed and power oscillations occurring in the power system due to various disturbances.