Setup and state based energy control of a grid-connected multipurpose hybrid hydrogen system

Grid connected hybrid hydrogen systems consisting of an electrolyzer, a fuel cell and a battery may become major parts of local energy systems in future. System setup is quite challenging due to different electric constraints and the need for a gas management system. This paper presents planning for a technical setup using a DC micro grid and a hydrogen pressure tank and the development of a new control strategy. In order to ensure grid stability a multi-level control strategy with decentralized and centralized control loops is used. A state-based energy control algorithm was developed to provide services to the electric grid and to optimize the system. Simulation results covering a real office and research building proved the energy control system to be feasible and revealed which control parameters are critical such as hydrogen tank pressure.