Voltage-Source Control for Green-Hydrogen Hybrid Energy Storage System With Operational Constraints and Current Rate Limiter

Green hydrogen produced from renewable energy generation (RES) is facilitating the energy transition. Due to the complicated operational constraints of green-hydrogen hybrid energy storage system (GH-HESS), the existing two-layer power-based control architecture is prevalent, but it heavily relies on the communication infrastructure and the prediction accuracy of RES’s power. Therefore, this paper proposes a novel voltage-source hierarchical control framework for the grid-connected GH-HESS to solve the above problems. Considering the electricity price, the hot-standby current and safety of the hydrogen production of the electrolyzer, the current allocation between hydrogen energy storage and power grid is achieved for the continuous stable operation of GH-HESS even in the situation with potential communication failure. When the current rate limiter is adopted for the fuel starvation phenomenon of fuel cell, the current feed-forward loop and current-based secondary control are designed to solve the trade-off problem between the current overshoot and convergence speed of the tradition voltage-source control, where the large current overshoot will cause irreversible damage to hydrogen energy storage. Battery energy storage rapidly responses the power fluctuation from RES, while the steady-state power vacancy is undertaken by hydrogen energy storage. Finally, a 800V DC microgrid based on NI-PXI real-time platform is built to validate its advantages.