Fault-Resilient Coordinated Voltage Control of Electric–Hydrogen Hybrid Microgrids with Battery–Fuel Cell Synergy
Abstract
Electric–hydrogen hybrid microgrids integrating distributed renewables with electrolysers can efficiently convert dispersed renewables into hydrogen, meeting local electricity demands. However, intermittent and uncertain renewables together with sudden load changes can cause severe bus voltage fluctuations and degrade power quality, especially in off-grid microgrids. Furthermore, the electrolyser’s auxiliary units require stable AC power supply even during fault events, which most likely occur at AC–DC converters. To ensure stability during renewable/load fluctuations and converter faults, this paper proposes a fault-resilient coordinated voltage control scheme by combining PI with piecewise active disturbance rejection control to mitigate DC bus voltage fluctuations during transient disturbances and regulates AC-side fuel cells via control switching to stabilise AC voltage after the complete disconnection converter fault. The scheme is tested using a simulated kW-scale electric–hydrogen hybrid microgrid in various operating scenarios and compared with conventional methods that combine PI with PI or linear active disturbance rejection control. The simulation results show that the proposed control scheme improves DC bus voltage stability by 14% during transient renewable/load fluctuations via the incorporation of PADRC and enhance system resilience against AC–DC converter faults through the synergy of batteries and fuel cells, which construct the voltage (and frequency) of DC and AC buses, respectively.