Rastreamento do ponto de máxima potência em painéis fotovoltaicos com busca da tensão de operação em banco de dados

Abstract

Every photovoltaic power generation system requires a maximum power point tracking algorithm (MPPT). Currently existing methods have high efficiency under conditions of the same temperature and solar radiation incident on the photovoltaic arrangement. However, when they are subjected to situations of partial shading, they may not obtain the global maximum, since these conditions cause the V x I curve of the panels to create local maximum power points. The most common MPPT methods might end up recognizing these points as if they were the maximum power points in the system. An aggravating factor to this problem is the fact that methods such as P&O, for example, generate many disturbances to the generator system, which may occur in instability in the set. The present work aims to propose a global maximum power point tracking technique that uses a variation of the Constant Voltage method, in which the voltage comes from data stored in a database, applied both in systems under partial shading conditions and in cases of climatic uniformity. The photovoltaic system was modeled on the PSIM software and its database generated by MATLAB and stored in SQL format. The proposed method is compared to the Constant Voltage, P&O and Incremental Conductance techniques. The simulation results showed that the variable voltage MPPT method using a database table search can track global maximum points under partial shading conditions, in addition to showing greater efficiency in the other tested conditions.