Modeling, analysis and comparison of solar photovoltaic array configurations under partial shading conditions

Abstract

The main purpose of this paper is to model, study and analyze the performance of different photovoltaic (PV) array configurations under various partial shading conditions (PSC). The aim is to improve the efficiency of PV systems in general by reducing mismatch losses and to select the most appropriate PV array configuration which provides the best performance i.e. the highest maximum power and hence the lowest relative power losses under partial shading conditions. For this purpose, a comprehensive study which considers all the available PV array configurations: Series (S), Parallel (P), Series–Parallel (SP), Total-Cross-Tied (TCT), Bridge-Linked (BL), and Honey-Comb (HC), is carried out under all possible scenarios of shading. The performance and output characteristics of these array configurations are analyzed and compared by using a 6 × 4 PV array size under various possible shading scenarios.

The Bishop model of a photovoltaic module which describes best the solar cell behavior at negative voltages is considered in this paper for modeling the PV arrays, and it is implemented by using the Simulink and SimPower software.

On the whole, the obtained results prove the superiority of the TCT configuration which provides the best performances under most cases of PSC: uneven or random distribution of partial shading. However, for some cases of PSC this is not the case because the performance depends strongly on the patterns of shade. Therefore, this paper will enrich and complement previous studies in this area through a detailed analysis and comprehensive study of the different PV array configurations under all possible shading scenarios which may occur in reality, the thing that has not been carried out previously.

In addition, these results represent an interesting guide which provides useful and relevant information concerning the performance of each PV array configuration under any pattern of shading. This will allow the estimation and prediction of maximum power and consequently will help to select the most suitable PV array configuration.