Design and Implementation of the Luenberger Observer for Estimating the Voltage Response of a PEM Electrolyzer During Supply Current Variations

Abstract

Equivalent electrical circuits (ECM) have proven to be effective in modeling the dynamic behavior of proton exchange membrane (PEM) electrolyzer voltage response. They are a valuable tool for studying the interactions between power electronics and PEM electrolyzers during dynamic operating conditions. Generally, the ECM takes into consideration the activation over-voltage that is present at both the anode and the cathode for the dynamic part of the model. Therefore, the monitoring of the ECM activation over-voltage is an important issue for the correct modeling of the PEM electrolyzer voltage. However, voltage sensors for this over-voltage are expensive and the reported observers of the PEM electrolyzer activation over-voltage are scarce and have not been validated over a sufficiently long time. This work aims at overcoming these drawbacks by proposing the use of a Luenberger observer to accurately estimate the activation over-voltage using an ECM. Based on this proposal, it is possible to build a device capable of emulating the electrolyzer voltage efficiently. Furthermore, a stability analysis of the observable system is provided to ensure its performance throughout the experiment period. Statistical results, based on experimental voltage data from a PEM electrolyzer QL–300, demonstrate the high accuracy and performance of the Luenberger observer under continuous changes in input currents, which demonstrates its robustness.

Keywords

• Electronic circuit model
• Luenberger observer
• PEM electrolyzer
• stability analysis
• voltage behavior