A fast and accurate approach for power losses quantification of photovoltaic power systems under partial-shading conditions

Mohammad K. Al-Smadi, The University of Alabama
Yousef Mahmoud, Kennesaw State University
Weidong Xiao, Faculty of Engineering


Predicting the output power of partially-shaded photovoltaic (PV) systems has a crucial role in the field of photovoltaic system studies and design. A significant number of models, circuit simulation techniques and power prediction formulations are proposed in the literature. However, several factors could limit their application such as computational burden, accuracy and their applicability to different levels of photovoltaic system. An analytical circuit-based approach is proposed to predict the output power and power losses of partially-shaded photovoltaic systems. The proposed approach is distinguished by high accuracy, low computational time and applicability to all photovoltaic system levels. Hence, it enables the assessment of partial shading mitigation ability of various photovoltaic system architectures. Furthermore, the proposed approach has no limitations on the size of photovoltaic system, for example, as in circuit-based simulation analysis. An extensive simulation-based comparison study for five partially-shaded photovoltaic systems is conducted to compare the accuracy and computational time of the proposed approach with the detailed, well-established single diode model. The accuracy of the proposed approach is also validated experimentally on a photovoltaic system of 12 series-connected photovoltaic modules. Furthermore, a set of comparisons with experimental measurements from the literature is presented.