Using a High-frequency Switching Power Converter for Online Electrochemical Impedance Spectroscopy on an Electrolyser System

Inhalt:
The push by organisations worldwide to use hydrogen as a fuel has subsequently motivated the energy market to explore opportunities to increase hydrogen production. Green hydrogen is one of the preferred solutions, which depends on the electrolysis process and involves the usage of power electronics and electrolyser systems. With usage, the electrolyser ages and reduces the overall production efficiency. Hence, a regular check on the electrolyser performance is required to determine degradation. Electrochemical Impedance Spectroscopy (EIS) is a commonly employed solution to measure impedance. In general, to perform EIS, the complete system is turned off to perform testing, making it inefficient and time-consuming. Therefore, to address this situation, this paper put forward a power converter design method capable of performing an online EIS test of the electrolyser system without shutting down any system or subsystem. A detailed explanation of the EIS methods and testing approaches is presented to define the requirement of an online method. The power converter design method for a PEM cell rated at 100 W will be presented. Intricacies in performing EIS at higher frequencies (> 10kHz) and their impact on component and printed circuit board design will be presented. Further, a laboratory-scale hardware design and validation in an actual electrolyser test bench will be demonstrated.