  In this paper, a hydrogen-based energy storage system (ESS) is proposed for
DC microgrids, which can potentially be integrated with battery ESS to meet the
needs of future grids with high renewable penetration. Hydrogen-based ESS can
provide a stable energy supply for a long time but has a slower response than
battery ESSs. However, a combination of battery and hydrogen storage provides
stable energy for an extended period of time and can easily handle the sudden
demands and surpluses of the microgrid. One of the main challenges in this
system is the integration of power electronics with fuel cell technology to
convert renewable energy into electricity seamlessly. This paper proposes a
system that uses an isolated DC-DC converter to activate clean hydrogen
production using an electrolyzer and then pressurize the hydrogen to store in a
tank. The pressured hydrogen becomes an essential input to the fuel cell, which
regulates and transforms it into electricity. The electricity produced is then
transferred to the grid using a DC-DC boost converter. A Simulink model of the
hybrid system with a 1 kV DC bus voltage is used to demonstrate the hydrogen
production and fuel cell behavior based on the demand and surplus power of the
loads. The proposed system simulates aspects of the power conversion,
electrolyzer, storage tank, and fuel cell needed for the proposed hybrid ESS.
Due to its economic feasibility, the polymer electrolyte membrane (PEM) is the
primary technology considered for the electrolyzer and fuel cell.
