Desenvolvimento de inversor fotovoltaico conectado à rede elétrica com sistema de armazenamento de energia e isolamento galvânico

Abstract

This research presents the development of a multi-phase Boost DC-DC converter in cascade with a half-bridge DC-AC converter. An isolated DC-AC system for applications in photovoltaic systems with energy storage system was developed. For the construction of this inverter, the DC-DC full bridge multi-phase Boost converter with high frequency isolating transformer was used. The multi-phase input current system reduced the size of magnetics and the current ripple through the input source. It was possible to modulate a voltage source into a load or use its output to inject current into the line grid when a half-bridge topology DC-AC converter was connected to the voltage bus. This photovoltaic inverter presents characteristics of uninterruptible power supply system. Following the current regulation of the guidelines on photovoltaic systems, the inverter was developed to supply the grid with unit power factor and harmonic distortion rate lower than 5%. The inverter was controlled by a digital signal processor using an embedded proportional-integer controller and a repetitive controller. Tests were performed with a functional 2000W prototype in laboratory.