Conversor CC-CC AGT-CCTE Bidirecional de Três Portas para Aplicação em Sistemas de Armazenamento com Energias Renováveis

Abstract

This study proposes a new bidirectional DC-DC converter topology with wide voltage gain, designed for integration into photovoltaic systems with battery energy storage. The proposed topology has three ports, two for the power supply (one powered by batteries and the other by photovoltaic modules) and a third for the load (output bus). Due to its bidirectional characteristics, the same converter facilitates power flow both from the batteries and/or modules to the load, as well as from the modules to the batteries. This thesis presents qualitative and quantitative analyses of the converter operating in Continuous Conduction Mode (CCM) for two power flow scenarios and considering different duty cycle values. The theoretical study demonstrated is validated through simulation and practical tests with the implementation of a prototype, where the results achieved are in conformity with the calculated voltage and current values. The main highlights include: operating the inductor at twice the switching frequency, markedly decreasing both the inductor’s size and the input current ripple; the potential to elevate the load bus voltage through adjustments to the transformation ratio; and the control process is simplified as the inherent topology facilitates natural balancing of power flow. The prototype implemented has the following specifications and nominal considerations: 48 V battery bus, 142 V photovoltaic module bus, 250 V load bus, 2 kW output power and 30 kHz switching frequency.