Design and Simulation of a Fuzzy Logic Controller for STATCOM in Power Systems

Abstract

This paper presents the design, implementation, and simulation-based evaluation of a Fuzzy Logic Controller (FLC) applied to a Static Synchronous Compensator (STATCOM) for voltage regulation and reactive power compensation in power systems. The proposed FLC replaces the conventional PI controller by employing a two-input (error and change of error) rule-based inference system with triangular membership functions and centroid defuzzification. A comprehensive MATLAB/Simulink model of the STATCOM in the d–q reference frame, including DC-link dynamics, is developed to investigate controller performance under realistic operating scenarios. Two representative test cases—a 20% step increase in reactive load and a 25% increase in coupling inductance—are used to assess transient response, overshoot, settling time, and steady-state accuracy. Comparative results indicate that the FLC significantly improves dynamic behavior: settling time is reduced from 0.45 s (PI) to 0.25 s (FLC), overshoot decreases from 8.2% to 2.5%, and steady-state voltage error improves from 0.015 P.u. to 0.002 p.u. Moreover, the fuzzy controller exhibits superior robustness to parameter variations. These findings demonstrate that fuzzy logic–based control provides enhanced transient performance and reliability for STATCOM applications, making it a promising strategy for modern power networks subject to nonlinearities and uncertainties. Key contributions include the tailored FLC rule base, systematic performance comparison with PI control, and demonstration of robustness through parametric perturbation tests.