The analysis of the shading effect on photovoltaic working performance based on single diode model

Clean and environmentally friendly photovoltaic (PV) technologies, which converts sunlight directly into electricity has grown dramatically in recent years and are now generally recognized as an alternative solution to many global scale problems such as energy demand, pollution, and environment safety.The performance of a photovoltaic (PV) modules and array are affected by temperature, solar insolation, shading, and array configuration. Often, the PV arrays get shadowed, completely or partially, by the passing clouds, neighboring buildings. Partial shading of a Solar Photovoltaic Module is one of the main causes of overheating of shaded cells and reduced energy yield of the module, therefore it is very important to understand and predict their impact in order to extract the maximum possible power of the array.Manufacturers of photovoltaic modules, instead of the parameters that forms I-V equation, provide only a few experimental data about electrical and thermal characteristics at STC conditoins. Estimating the electrical performance of a PV module or system requires to obtain these parameters and translating the electrical performance from STC to the outdoor conditions.The objective of this study is to investigate the harmful effects of partial shading on a solar module performance and compare the performances of different connections of solar panels. The one diode model is used in order to estimate the electrical parameters of a solar cell model, using information given in module datasheet. The model has been implemented in MATLAB and takes into account the series and parallel resistance of the cell. The proposed research has the following goalsFirstly, the one diode model parameters which form the i-v equation are determined. Then, the results obtained from simulations for different temperature and irradiance conditions are compared with those given in the datasheet. Finally, the effects of non-uniform solar irradiation distribution (partial shadow) on energy output of different interconnected configurations in photovoltaic (PV) arrays is investigated to be able to predict the performance of solar PV arrays in order to optimize output power. In addition, the research of the optimal layout of photovoltaic (PV) modules in a PV array giving the maximum output power under different shaded working conditions is carried out.The model has been experimentally validate with measurements on three 75 W monocrystalline silicon modules. This research is useful tool for power electronics designers and researchers who need an effective and straightforward way to model and simulate the effects of shading on photovoltaic arrays.