Decentralized Energy Management of Renewable Hydrogen Production Systems Without Communication Networks

With the increasing penetration of renewable generation, producing renewable hydrogen by water electrolysis has become a promising development. For hydrogen production systems integrated with renewable energy sources (RESs), alkaline electrolyzers (AELs), and energy storage devices, its energy management system (EMS) not only controls the RESs’ operating points to capture more renewable energy but also regulates the AELs and energy storage devices’ operating power to achieve dc bus voltage regulation, dynamic power sharing, power regulation of AELs, state-of-charge regulation of energy storage devices, etc. In this article, a decentralized EMS is proposed to achieve the above objectives. The proposed EMS can indirectly improve the system's efficiency and service life by ensuring that the AEL's operating power is always above the minimum recommended operating power and it only absorbs the low-frequency part of renewable power fluctuations. Besides, the proposed EMS can reduce system costs and enhance system reliability by eliminating communication networks. Furthermore, the operational principle of the proposed EMS and the system design and analysis are elaborated. The proposed EMS's effectiveness is verified by hardware-in-the-loop real-time simulations.