A Four-port Bidirectional DC-DC Converter for Renewable Energy-Battery-DC Microgrid System

This paper proposed a four-port bidirectional DC-DC converter for multiple energy sources and DC-microgrid application. The bidirectional power flow between the battery and the DC-microgrid makes it possible to participate the power management of the microgrid. Besides, the battery can be charged by both renewable energy sources and the DC-microgrid, which makes it suitable for the application where two renewable energy sources and battery are used. In this paper, a 1 kW prototype was built to interface a photovoltaic (PV) panel, a wind turbine generator (WTG), and battery to the DC-microgrid system. The simulation and experimental results not only validate the working principle of the converter, but shows that the bidirectional power flow can be achieved by shifting the phase angle of the primary and secondary switches.