Uma contribuição ao estudo e desenvolvimento de inversores solares com duas entradas de MPPT independentes e capacidade de rastreamento do ponto de máxima potência em condições de sombreamento parcial

Abstract

This work presents two strategies used to improve the extraction of solar energy from a photovoltaic system. The first of these consists of the use of a multistring solar inverter type which is composed of two photovoltaic strings independently connected to DC-DC Boost converters. These are endowed with classical MPPT (Maximum Power Point Tracking) P&O (Perturb and Observe) algorithms. The second strategy is to improve the P&O technique by implementing an algorithm specifically designed to detect the global maximum power point. The use of a multistring structure associated to the developed algorithm aims to mitigate the negative effect caused by partial shading, due to dirt in the solar panels, lack of maintenance especially in places where access is difficult, shadowing caused by nearby objects and so on. With the algorithm created, each converter is able to extract the maximum available power from its respective string even under conditions of partial shading and variations of solar radiation, thus maximizing the generation of photovoltaic solar energy. The design specifications, the modeling analysis of the converter used and the control strategy are detailed in the course of this work. Finally, simulation and experimental results are presented corroborating with the theory exposed.