A Centralized Control of a DC Hydrogen-Based Microgrid for Grid Support in Distribution Systems

Hydrogen-based technologies, including electrolyzers and fuel cells, are emerging as valuable flexible resources in distribution networks, but their role in grid support is not yet fully recognized. This paper proposes a Central Plant Controller that combines a finite-state machine with PI-based feedback control schemes for the provision of grid services by controlling a PV-electrolyzer-fuel cell DC microgrid interfaced with the AC grid. The controller is experimentally validated on a Power Hardware-in-the-Loop platform connected to the public distribution grid. The implemented testing setup reproduces real measurement granularity, asynchronous updates and communication latencies, thus ensuring both high testing coverage and fidelity. By adopting real PV data measurements with wide fluctuations, the conducted tests demonstrate that the proposed controller is able to accurately actuate all mandated regulation services, and handle simultaneous control requests, in compliance with the Italian Grid Code. Even employing hydrogen-based resources, the overall control loops remains compatible with normative timing requirements, settling within one minute for active power regulation. Moreover, results highlight the robustness of the controller, demonstrating its adaptability to system parameter changes, e.g. distinct electrolyzer dynamics. The described findings confirm the controller ability to provide reliable and standard-compliant grid support, and advance practices in the exploitation of hydrogen-based flexible resources for the provision of grid services in the operation of distribution power systems.