Compatible matching and synergy operation optimization of hydrogen-electric hybrid energy storage system in DC microgrid

Hydrogen energy storage (HES) systems could balanced source-load mismatches in DC microgrids. By combining HES with electrical energy storage (EES), the start-up delay and rapid degradation of HES under fluctuating inputs can be mitigated, enhancing system adaptability. However, without proper power allocation and operational optimization, system efficiency and the lifespan of HES and EES decrease. Accordingly, this paper proposes a compatible matching and synergy operation optimization for hydrogen-electric hybrid energy storage systems (H-E HESS). Firstly, Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) is developed to decompose power fluctuation signals into frequency components, and the Hilbert transform calculates the energy value to determine high- and low-frequency dividing points. Next, a system power allocation strategy is formulated through the fast response of the EES to compensate for the delay in the start-up of the HES. A multi-objective optimization model is then developed to balance efficiency and lifespan, which is solved by the NSGA-III algorithm. Finally, case studies show that the proposed strategy improves efficiency by 17.95 % and 8.34 %, reduces degradation rates by 1 % and 0.71 %, and shortens system response time in 1 s, compared to Schemes I and II. The strategy’s effectiveness is also validated through an experimental platform in a hydrogen-electric coupled DC microgrid demonstration project.