Maximum power point tracking algorithm of SPVA under inhomogeneous irradiation conditions: A modified Fibonacci search based approach

This paper proposes a maximum power point tracking (MPPT) algorithm that enables extraction of maximum possible power from the solar photovoltaic array under all irradiation conditions. The electrical characteristics of the photovoltaic (PV) array exhibit multiple steps and peaks under partial shaded conditions because of the inclusion of bypass diodes. The location of the global peak is however dependent on the size and configuration of the array besides the shade intensity and pattern. Conventional MPPT algorithms cannot differentiate the global peak from the local peaks. The Fibonacci based search algorithm that has already been proposed is fast and accurate but, it fails under certain shading conditions. This paper proposes a modification in the Fibonacci based search by introducing two more search points in the search interval to improve the tracking reliability and accurate identification of the global peak. The efficiency of the proposed algorithm is verified for few shade patterns and the results are presented.