A Novel Approach for Maximum Power Tracking From Curved Thin-Film Solar Photovoltaic Arrays Under Changing Environmental Conditions

Abstract

A novel approach for maximum power tracking from curved thin-film flexible photovoltaic (FPV) modules is described. Power-voltage characteristics of curved FPV modules exhibit multiple-peak patterns. The proposed approach consists of modeling the curved FPV modules and optimizing the power yield using this model. A typical curve shape is considered, which is fairly representative of several actual applications such as building integrated PVs (BIPVs), curved roofs, tents, aerostats, etc. Extensive experimentation with FPV modules for various curve angles, in conjunction with regression analysis, has led to empirical models that relate FPV module parameters[Isc, VOC, and fill factor (FF)] with environmental factors and layout design parameters (curve shape and angle). Based on these models, a new “scanning window” technique (SWT) is proposed to maximize the power yield of curved FPV modules. As the FF for curved FPVs is highly dynamic, the SWT proves to be highly effective. A solar angle threshold (obtained in terms of estimated solar angle) determines whether to expect single or multiple power peak characteristics and whether to use the conventional perturb and observe method or the SWT. This results in fast and accurate tracking of maximum power point. The proposed approach facilitates optimum layout designs for BIPVs and stand-alone PV systems.