Comparative Analysis of Decoupling Control Methods for Multiport-Isolated Bidirectional DC-DC Converter with Hydrogen Storage System Integration

Hydrogen storage systems have garnered increasing interest over the years, owing to their positive environmental implications. The efficiency of such systems is closely related to the efficiency of their power electronics interface. Multiport-isolated bidirectional DC-DC converters offer several advantages over other converters, including lower power density, bidirectional functionality, reduced component counts, soft switching ability, and a reduced number of conversion stages. However, these converters suffer from the cross-coupling effect of the control variables with the power dissipated at each port, which significantly impacts the system's response to step changes and limits its reliability. This paper presents a comprehensive comparison of three different decoupling control methods for multiport-isolated DC-DC converter to establish the effects of cross-coupling. Simplified, Inverted, and GH matrix-decoupling control methods are implemented. The simulation results show that better system response is achieved using decoupling control methods. The GH matrix decoupling method provides superior performance in terms of reduced peak power deviation and settling time when cross-coupling occurs.