Grid integration of a 500 kW alkaline electrolyzer system for harmonic analysis and robust control

Abstract

In the past decades, wind and solar energy installation has rapidly increased. The electric grid has been ever increasingly penetrated with such intermittent renewable sources, which inevitably increase the schedule difficulty and cause stability issues. To solve such problems and efficiently utilize the renewable energy, electrolyzer plants are integrated into the grid. This work provides a simulation result of a 500 kW alkaline electrolyzer system including converter topology and electrolyzer performance modeling. Two case studies are carried out in MATLAB®/Simulink® and PLECS to investigate the harmonic distortion and system response during voltage deviation in the distribution grid. The simulation result indicates that different short circuit ratio values affect the total harmonic distortion and the harmonic sidebands are mainly affected by controller bandwidth and switching frequency. The designed system maintains 95% DC link voltage even when subjected to a 20% voltage dip in the point of connection.

Keywords

• Power-to-X
• Green hydrogen
• Alkaline electrolyzer
• Harmonic analysis
• Medium voltage converter