A High-Power Converter for Electrolytic Hydrogen Production Based on DC Microgrid

In the wind-solar-hydrogen storage DC microgrid architecture, the hydrogen production link needs to use a DC-DC converter to connect the DC bus and the electrolyzer. According to the characteristics of alkaline electrolyzer and DC microgrids, a two-stage DC/DC converter as the supply of the electrolyzer is proposed in this paper. Specifically, the front stage of the cascade converter is composed of two multi-resonant modules, which adopt the structure of input series and output parallel to adapt to the DC bus of higher voltage levels. The rear stage of the cascade converter adopts three-phase interleaved Buck to reduce the influence of load sudden change on the front stage. This two-stage converter is able to meet the requirements of high-voltage input as well as low-voltage and high-current output, and has the characteristics of high step-down ratio, high efficiency and electrical isolation. In addition, considering that the actual resonance parameters may be different, the power imbalance between the two modules in the front stage is analyzed, and a control method suitable for the cascade converter is designed, and its effectiveness is verified by simulation results.