Simulation of photovoltaic centrals with dynamic shading

Abstract

The increase in the power of photovoltaic systems involves a significant grow in the number of modules that make them up. The known problems caused by the shading are not usually taken into account in the design of a photovoltaic central away from urban environments. The aims of this study are to obtain a model for simulation of photovoltaic plants, representing the array under different conditions of dynamic shading, and to investigate its effects on configurations of modules array and converters. Performance measures are also discussed in order to find those most suitable for plants comparison in this context. Analyzing the efficiency of the maximum power point tracker and the inverter under different conditions of dynamic shading, using one or more inverters, a better performance is generally achieved by reducing the number of modules in series and by increasing the number of those in parallel. But the parallel connections are only suitable in certain conditions and the optimal number of parallels can not be established trivially. The results show that the operating conditions determine the most efficient connection scheme with partial shading by using central inverter. Without using an optimization algorithm, we achieve results with central inverters not far from using microinverters. These results indicate that using the proposed simulator and an optimization algorithm, it can be optimize the complete system energy and take advantage of lower costs of central inverters for large photovoltaic plants.