UPFC controller design for power system stabilization with Particle-Swarm Optimization algorithm

A new robust controller for unified power flow controller (UPFC) has been designed to damp local and interarea oscillations. In this paper an optimization method based on particle-swarm optimization (PSO) algorithm is presented to optimize the parameters of a fuzzy PI controller of a UPFC in order to enhance the power system transient stability. The function based Takagi-Sugeno-Kang (TSK) fuzzy controller has minimum number of rules (only two rules) and generates the proportional action which by one-to-two inference mapping presents a variable gain PI controller. This single-input function based scheme dispenses the gain dependency of the proportional or integral gains and generates independent control actions. Computer simulation results on a two-area four-machine test system of 12 buses confirm the performance of the new approach in damping the local and inter-area oscillations.