Comparative Measurement Study of 12-Pulse Thyristor and 2-Level Voltage Source Converter in PEM Water Electrolyzer Test Setup

The need for green hydrogen has created the need to study water electrolysis process in more detail. Current state-of-the-art electrification solutions are thyristor-transformer rectifier systems and the electrolysers are typically connected in parallel or two in series with middle point grounding. In this paper, the electrification and the rectifier is studied. It is imperative to try to increase the voltage instead of current as it is known from the field of power electronics that increasing current increases costs. Therefore, in this paper the parallel and serial connections of PEM electrolyser stack system in the same system is compared with commercial thyristor and PWM-based active rectifiers. The focus is on the electrical quantities and Specific Energy Consumption (SEC). Hydrogen production in both connection methods is measured and reported.