Identification and Power Electronic Module Design of a Solar Powered Hydrogen Electrolyzer

Comparing to conventional fossil fuels, hydrogen yields no emission through various thermal and electro-chemical processes. Beyond this feature, high energy density and transportability make hydrogen an attractive candidate for the future energy systems. Hydrogen gas can be harvested from a wide selection of hydrogen enriched molecules through different reforming processes. Among a variety of fuel candidates, water is a readily available resource; and electrolysis of water can take place in relatively low temperature and low pressure. In this paper, solar energy is harvested by the photovoltaic panels, and processed using a dc-dc converter to supply an alkaline electrolyzer. Due to the complexity of the electrolyzer load, the small signal model is obtained firstly using the current/load perturbation method at the rated operation condition. In order to supply low ripple current to the electrolyzer stack, a dual-phase synchronous buck converter is designed and implemented in a dedicated hardware prototype. The control algorithm is implemented in a digital signal controller and the steady state performance of the system is experimentally verified.