A decentralized dynamic power sharing strategy for renewable hybrid hydrogen electrolyzer systems without communication networks

The utilization of renewable energy for water electrolysis to produce hydrogen has emerged as an increasingly intriguing avenue due to its efficiency and environmental friendliness. However, challenges arise from the variability of 100 % renewable energy, which affects hydrogen output, the lifespan of electrolyzers, and system reliability. This paper proposes an improved decentralized energy management strategy, applied to a hybrid electrolyzer system integrated with alkaline electrolyzers (ALKELs), proton exchange membrane electrolyzers (PEMELs), and energy storage devices. The proposed strategy facilitates dynamic power sharing, power modulation of the electrolyzers, bus voltage regulation, and state of charge adjustment of the batteries without reliance on a communication network. Specifically, ALKELs, PEMELs, and batteries are designated to absorb the low-frequency, mid-frequency, and high-frequency components of renewable energy power, respectively, ensuring that the power supplied to ALKELs and PEMELs remains at or above the minimum recommended operational power throughout the process. Compared to systems without the proposed strategy, the implementation results in a 10.26 % increase in total hydrogen production. By fully accounting for the dynamic characteristics of each system component, the strategy ensures high levels of autonomy and operational stability. The effectiveness of the proposed strategy has been validated through hardware-in-the-loop simulations.