No abstract

Recently, the use of electrolyzers for hydrogen production through water electrolysis is of great interest in the industrial field to replace current hydrogen production pathways based on fossil fuels (e.g. oil, coal). The electrolyzers must be supplied with a very low DC voltage in order to produce hydrogen from the deionized water. For this reason, DC-DC step-down converters are generally used. However, these topologies present several drawbacks from output current ripple and voltage gain point of view. In order to meet these expectations, interleaved DC-DC step-down converters are considered as promising and interesting candidates to supply proton exchange membrane (PEM) electrolyzers. Indeed, these converters offer some advantages including output current ripple reduction and reliability in case of power switch failures. In addition, over the last decade, many improvements have been brought to these topologies with the aim to enhance their conversion gain. Hence, the main goal of this paper is to carry out a thorough state-of-the-art of different interleaved step-down DC-DC topologies featuring a high voltage gain, needed for PEM electrolyzer applications.

In order to face the intermittent nature of renewable energy sources (RES), hydrogen production and storage are considered an attractive solution. Nowadays, RES (e.g., wind, photovoltaic), and fossil fuels (e.g., coal, natural gas) are the various resources available on the planet Earth to produce hydrogen. Water electrolysis is one of the most interesting ways of producing hydrogen from RES; this electrochemical reaction is realized through an electrolyzer. Usually, DC–DC step‐down converters are used in the hydrogen production systems since electrolyzers must be supplied with a very low DC voltage to generate hydrogen from deionized water. Although these converters are widely used, they have several drawbacks from output current ripples and energy efficiency point of view. In order to meet the requirements for electrolyzer applications, a stacked interleaved DC–DC step‐down converter has been used to carry out this work. The objective of this paper is to develop a control law of the studied converter based on the current flowing through in one of the phases. This control allows reducing phase current overshoot and oscillations, and consequently conduction losses. Finally, by an experimental investigation, the performance of the current controller from overshoot, stability and oscillation point of view has been assessed.