Maximum power point tracking of partially shaded solar PV system using modified Fibonacci search method with fuzzy controller

This paper presents the modified Fibonacci search based Maximum Power Point Tracking (MPPT) scheme for a Solar Photovoltaic Array (SPVA) under partial shaded conditions. Partial shaded SPV modules produce several local maximum power points, which makes the tracking of the global maximum power a difficult task. Most of conventional tracking methods fail to work properly under these nonuniform insolation conditions. The real Fibonacci search based MPPT fails to track the global peak (GP) under partial shaded conditions. This paper improves the method by considering power ripple and wide search range so that the proposed method tracks GP for all the conditions. It is checked for different shading patterns through simulation and verified experimentally. In this paper, the advantage of using Fuzzy Logic Controller (FLC) is also presented. Fuzzy rules are optimized using genetic algorithm (GA). Comparative studies have been made for Proportional plus Integral (PI), nonoptimized FLC and GA optimized FLC. From the simulation results, it is observed that the fuzzy controller reduces error and it gives rapid response to environmental changes. Furthermore, it does not require any tuning of the parameters, unlike conventional PI controller, wherein the controller gain parameters needs to be changed when solar insolation changes. (C) 2012 Elsevier Ltd. All rights reserved.