Power Balancing Services from Electrolyzer on Offshore Energy Hub

This paper explores the feasibility of integrating an Alkaline electrolyzer into an offshore energy hub to coordinate active power control among all system units. The dynamic electrolyzer model was implemented with cascaded power supply control. The physical and safety limitations (e.g. ramp rate limit) of the Alkaline electrolyzer were considered. The 4 GW offshore energy hub, with the electrolyzer model, including the coordinated control, was built and simulated in PowerFactory. The system is tested under two main fault scenarios. First, a fault disconnects the offshore wind power plants, causing the system to experience under-frequency. An HVDC converter pole fault is then considered, leading to an over-frequency situation where wind power exceeds transmission capacity. Two frequency responses, hysteresis droop controller and automatic generation control, were implemented in electrolyzer’s control scheme. The feasibility of hydrogen plants in balancing the offshore energy hub was shown in simulations.