Asymmetrical fuzzy logic control-based MPPT algorithm for stand-alone photovoltaic systems under partially shaded conditions

Abstract

Partial Shading Conditions (PSCs) in Photovoltaic (PV) system represent an inevasible situation that curtails the PV array output by exhibiting multiple peaks in its Power-Voltage (P-V) curve. The multiple peaks consist of a single Global Maximum Power Point (GMPP) and many Local Maximum Power Points (LMPPs). The presence of multiple peaks makes tracking of maximum power point quite difficult and demands an efficient controller to track the global peak of the P-V curve. In the present work, a novel intelligent Asymmetrical Fuzzy Logic Control (AFLC) based Maximum Power Point Tracking (MPPT) algorithm was proposed for tracking GMPP. The fuzzy membership functions of the proposed algorithm were optimized using a heuristic approach. The algorithm was designed, developed, and analyzed using MATLAB/simulink. Furthermore, to establish the superiority of the proposed AFLC algorithm, it was compared with conventional Perturb and Observe (P&O) algorithm and intelligent Fuzzy Logic Control (FLC) based algorithm for GMPP tracking and shading losses under Standard Test Condition (STC) and partially shaded conditions.