Static behavior and global maximum power point characteristics of photovoltaic array under partial shading

Partial shading (PS) in photovoltaic array is one of the main problems that can be faced when extracting solar energy. It takes place when certain spots of the photovoltaic (PV) array are shaded, while other parts are left uniformly irradiated. PS remarkably reduces the output power and could damage shaded cells if they are not protected. As the PS effect is not proportional to the shaded area and the P-V curve exhibits several local maximum power points, conventional maximum power point tracking (MPPT) techniques become ineffective. In this paper, we analyze the behavior of the array output power under PS throw simulation of several possible scenarios in order to approximate the I-V (P-V) characteristic and facilitate the extraction of the maximum power of the PV array.