A Fuzzy Tuned Adaptive PI Controller Based UPFC to Improve Power Oscillations Damping in Multi Machine Power System

Abstract

In this paper, a fuzzy tuned adaptive PI controller (FTAPIC) was proposed for the series inverter of a unified power flow controller (UPFC), which controls the real power flow in a transmission line, to improve power system oscillations damping. In the proposed control method the parameters of a PI controller namely proportional gain (Kp) and integral gain (Ki) were adjusted on-line by a fuzzy logic controller (FLC). The proposed FTAPIC controller was designed using a very simple control knowledge base and simple membership functions (MFs). To compare performances of the proposed FTAPIC and the standard PI controller, transient response studies were conducted using MATLAB/Simulink® software, over a wide range of operating conditions. The simulation results have shown that the UPFC equipped with a FTAPIC provide better performance compared to UPFC equipped with standard PI controller.