Achieving Stability and Optimality: Control Strategy for a Wind Turbine Supplying an Electrolyzer in the Islanded Storage-less Microgrid
Bosen Yang, Kang Ma, Jin Lin, Mingjun Zhang, QiweiDuan, Zhendong Ji, Zhi Liu, Yonghua Song
TL;DR
The paper addresses the challenge of supplying an electrolyzer in an islanded, storage-less wind-powered microgrid without grid-forming BESS. It presents a novel control framework that fixes the microgrid frequency at $50$ Hz via the MSC while regulating voltage through the electrolyzer-side converter and supporting IPBC dynamics, enabling stable operation and maximized hydrogen production. A unique 24-UR current-source rectifier topology and a steady-state scheduling model are introduced, linking DFIG MPPT behavior and AEL ramp constraints to the objective of maximizing $P_{AEL}$. The approach is validated through Matlab/Simulink simulations across multiple cases, including normal operation, ramp limitations, strong-wind emergencies, mode switching, and stochastic wind, demonstrating voltage/frequency stability, effective hydrogen production, and resilience without BESS. This work offers a practical pathway to reduce LCOH in green hydrogen production by leveraging converter-dominated islanded microgrids and coordinated control with mode switching.
Abstract
Wind power generation supplying electrolyzers in islanded microgrids is an essential technical pathway for green hydrogen production, attracting growing attention in the transition towards net zero carbon emissions. Both academia and industry widely recognize that islanded AC microgrids normally rely on battery energy storage systems (BESSs) for grid-forming functions. However, the high cost of BESS significantly increases the levelized cost of hydrogen (LCOH), compromising economic feasibility. To address this challenge and reduce the LCOH, this paper focuses on a wind turbine (WT) supplying an electrolyzer in a storage-less microgrid and identifies a unique characteristic that challenges the conventional understanding of this microgrid: active power is coupled with microgrid voltage rather than frequency, the latter being entirely decoupled from active power balance. Based on this unique characteristic, this paper develops a new control strategy that maintains power balance, stabilizes the voltage and frequency, and maximizes hydrogen production. The effectiveness of the control strategy is validated through case studies conducted in Matlab/Simulink, especially its capability to maintain stability while maximizing hydrogen production under various conditions.