Estudo e aplicações de indutores variáveis para MPPT em sistemas fotovoltaicos

Abstract

This master course dissertation presents a proposal of the application of variable inductor technique for inductor’s design presented in the converters used as MPPT in photovoltaic systems. The fact of these technique makes it possible to storing larger amounts of energy in the inductor’s core is the motivation of this work. Therefore, this work applies the variable inductor’s technique for a design of a buck-boost converter in order to decrease the volume of the inductor’s core. It’s also proposed this application in the LLC resonant converter design, in order to perform the MPPT, presenting as an alternative of control, usually done by modifying the switching frequency. After a literature review, which makes possible the project of the system proposed, results were taken by the application of the converter’s project. These results shown that the application of variable inductor’s technique made possible to reduce the inductor’s core volume up to 64%., however, it was verified that the overall efficiency of the converter was penalized under high irradiation conditions. It was also verified the possibility to keep the switching frequency fixed, by varying the inductance value, for the application of variable inductor’s technique in LCC resonant converter. For this case the results showed a penalization of system’s overall efficiency under lower conditions of irradiance, however, at maximum power considered, the efficiency is optimized.