A Fuzzy Logic MPPT Algorithm with a PI Controller for a Standalone PV System under Variable Weather and Load Conditions

Abstract

This article proposes a standalone application for operating a photovoltaic module at the Maximum Power Point (MPP) under variable weather conditions and using a Fuzzy Logic Control (FLC) Maximum Power Point Tracking (MPPT) algorithm to increase the efficiency and lower the costs. The DC-DC converter provides a constant output voltage whatever the weather conditions and variable load thanks to the PI controller by local compensation of the disturbances. This system has been analyzed and implemented under the Matlab/Simulink environment. Simulation results under different weather conditions were observed. The MPPT algorithm based on FLC gives a precision between 95.5% and 99.5%. The parameters of the PI controller are calculated by the Ziegler-Nichols method. From the simulation results, we can see that the control by the PI controller effectively solves the instability of the system voltage, keeping the DC-DC converter voltage steady despite the varying weather and load conditions.