Fuzzy Logic Controller Based Three-Phase Shunt Active Power Filter for Compensating Harmonics and Reactive Power under Unbalanced Mains Voltages

In this paper, a shunt Active Power Filter (APF) is proposed for the compensation of harmonic currents and reactive power in polluted environment and under unbalanced mains voltage. For this purpose, a fuzzy logic controller is developed to adjust the energy storage of the dc voltage. The reference current computation of the shunt APF is based on the instantaneous reactive power (p-q) theory. We applied the system based on PLL (Phase Locked Loop) in order to control the shunt APF under unbalanced mains voltage. Hysteresis Controllers is used to generate switching signals of the voltage source inverter. MATLAB/SIMULINK power system toolbox is used to simulate the proposed system. The results show the effectiveness of fuzzy logic control to optimize the energy storage of the DC capacitor, the sinusoidal form of the current and the perfect of the reactive power compensation. The proposed system has achieved a low Total Harmonic Distortion (THD)which demonstrates the effectiveness of the presented method.