Buck-Boost-Integrated, Dual-Active Bridge-Based Four-Port Interface for Hybrid Energy Systems

A power electronic interface using four ports to interconnect the solar photovoltaic panels, wind generator, battery, and DC microgrid is proposed in this paper. The proposed converter employs a two-winding transformer to interface 380 V of the DC microgrid with all the other three ports, namely, the solar port, wind port, and battery port, which have relatively low nominal voltages. However, the power transfer from solar and wind ports to the battery port bypasses this transformer, thus reducing the potential power losses in the transformer. Furthermore, the maximum and minimum values of the voltage range in which the converter can tap maximum power from solar and wind sources are not constrained by the battery voltage, thus improving the power extraction capability of the multiport converter. The controller for the multiport converter has been developed for extracting the maximum power from renewable sources and to control the charging current of the battery. The simulated response of the converter was studied using the MATLAB/Simulink platform. The simulated response confirms the operation of the converter.