Maximum Power Estimation of a Partially Shaded PV String Using a Novel Elliptical Foci Based Technique

In this article, a novel elliptical foci based MPP estimation method is proposed for photovoltaic (PV) string under partial shading conditions (PSCs). In this method, an implicit I-V characteristic equation of single diode model (SDM) PV module is used. In partially shaded string, the proposed method first identifies the voltage range in which the global maximum power point (GMPP) exists. Afterwards, the maximum power is estimated using elliptical foci technique. The major advantage of the proposed method is that the MPP can be estimated without the need of approximation in current-voltage (I-V) expression or plotting of the whole I-V curve. The proposed method is developed and tested under different environmental conditions (DECs) using MATLAB platform. Further, to validate the accuracy of the proposed method, 3 uniform and 3 nonuniform shading conditions are considered. A comparison of proposed method with different existing MPP methods is carried out. The results show the proposed method is more accurate and efficient.