Modeling of a Combined PEM Electrolyzer and Quadratic Step-Down Converter for the Generation of Green Hydrogen

Currently, hydrogen is considered a primary option for replacing fossil fuels across various processes, which can reduce greenhouse gas emissions and mitigate global warming. To achieve these goals, hydrogen should be produced using non-polluting processes, such as water electrolysis powered by renewable energy sources. This method requires feeding the converter with an unregulated voltage source. A quadratic step-down converter can be connected between a DC source and a Proton Exchange Membrane (PEM) electrolyzer to produce hydrogen. To mitigate variations in the generated output voltage and intermittent power supply to a PEM electrolyzer, a DC-DC converter is used as an interface. A converter model can be combined with a static or dynamic model of the PEM electrolyzer to yield switched models and, after averaging, linear state-space models. These models can be used to design robust controllers for green hydrogen production, thus significantly reducing greenhouse gas emissions. This work presents experimental and simulation results.