Optimal tuning of Power System Stabilizers in a multi-machine system using firefly algorithm

One of the most important characteristics of power systems as dynamic plants is maintaining their stability when subjected to disturbances. Power System Stabilizers (PSSs) are the most used devices to damp Low Frequency Oscillations (LFO) and enhance power system dynamic stability due to their flexibility, easy implementation and low cost. This paper presents a novel approach for designing PSSs to improve damping of power system low frequency oscillations under dynamic disturbances. This problem is formulated as a multi-objective optimization problem with the aim of tuning the PSSs parameters in the case of eigenvalues analysis and nonlinear time-domain simulation. The Firefly (FF) Algorithm which has been found robust in solving these kinds of optimization problems is selected as a tool to find the optimum solution. Simulations are executed on the New England- New York sixteen-machine power system under different operating conditions. Results obtained from this method are presented and compared with the those using Particle Swarm Optimization (PSO) method. At last, for better deduction, comparisons are done through some performance indices. Results confirm better performance of the designed PSSs based on the proposed method in amending damping torque and system oscillations stability.