A Petri Net Approach to Reliability and Degradation Modelling of a PEM Electrolyser

Dynamic reliability modelling is crucial for complex, modern engineering systems such as proton exchange membrane (PEM) electrolysers, where multiple components interact and operating conditions may fluctuate significantly over time. In such systems, traditional static reliability assessment methods often necessitate oversimplifying assumptions and have limitations when it comes to accurately modelling phenomena, such as degradation, failures between individual cells within the stack, and their dependencies on variable environmental conditions. Addressing these challenges, this paper proposes a novel Petri Net-based approach to model the degradation and reliability characteristics of electrolysers. The Petri Net method is highly effective in representing dynamic behaviours, concurrent processes, and interdependencies, thereby offering a comprehensive framework for the evaluation of PEM electrolyser degradation and reliability. This approach accounts for concurrent degradation processes among the cells. Furthermore, the lifetime and operational performance of a PEM electrolyser are strongly influenced by a range of operating conditions, which include, temperature, pressure, and current density, all of which are incorporated into the model, given their significant impact on both cell degradation and overall system reliability. The developed model is computed using Monte Carlo simulation to determine cell-stack degradation, failure and reliability metrics over time. The findings aim to support and inform dynamic reliability assessment processes in the hydrogen industry.

Keywords: PEM Electrolyser, Petri Nets, Degradation, Reliability.