PEM-Based Green Hydrogen Plant: Harmonic Issues and Mitigation using Active and Passive Filters ¹

Grid compliance for harmonic current injection of hydrogen generation plant based on proton exchange membrane (PEM) electrolyzer technologies is of particular importance for a hydrogen-based economy. This paper studies harmonic mitigation strategy using commercial-off-the-shelf (COTS) active harmonic filter (AHF) product in 6-pulse and 12-pulse thyristor rectifier based green hydrogen plant's electrical designs. It shows that for multi-megawatt (MW) plant a modular design of the AHFs is a good option. A 6-pulse rectifier powered plant needs a passive filter to mitigate the large 5<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> order harmonic, while AHFs can be used to mitigate harmonics higher than the 5<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> order. A 12-pulse rectifier can use AHFs to mitigate 7th order and up harmonics, while using an 11<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> order passive filter to meet the IEEE 519 requirements.