Dynamic Stability Enhancement of a Multi Machine Electric Power System Using Unified Power Flow Controller

This study presents the application of Unified Power Flow Controller (UPFC) to improvement dynamic stability of a multi-machine electric power system installed with UPFC. Since UPFC is considered to mitigate Low Frequency Oscillations (LFO) and stability enhancement, therefore a supplementary stabilizer based on UPFC (like power system stabilizer) is designed to reach the defined purpose. Intelligence optimization methods such as Particle Swarm Optimization (PSO) and Genetic Algorithms (GA) are considered for tuning the parameters of UPFC supplementary stabilizer. To show effectiveness of UPFC and also comparing these two optimization methods, the proposed methods are applied and simulated. Several nonlinear time-domain simulation tests visibly show the ability of UPFC in damping of power system oscillations and consequently stability enhancement. Also Simulation results emphasis on the better performance of PSO based Stabilizer in comparison with GA based Stabilizer.