Reliability evaluation of electricity-hydrogen integrated energy system considering aging failure based on data-driven polynomial chaos expansion

Existing reliability evaluations of Electricity-Hydrogen Integrated Energy System (EH-IES) neglect the aging failure mechanisms and models of electrolyzers and hydrogen fuel cells, and suffer from low computational efficiency in solving reliability evaluation problems. To address these issues, this paper proposes a novel reliability evaluation method for EH-IES that considers the aging failure of electric-hydrogen conversion devices using a Data-Driven Polynomial Chaos Expansion (DPCE). First, the degradation effects of critical components, such as proton exchange membrane electrodes, during the electrochemical reaction processes of proton exchange membrane electrolyzers and hydrogen fuel cells are analyzed. The impact of material degradation on the electrochemical equations of these devices is investigated, and the degree of operational voltage degradation in electric-hydrogen conversion devices is quantified. Based on this, an aging failure reliability evaluation model for electrolyzers and hydrogen fuel cells is developed. Second, an optimal load shedding model for EH-IES is established, taking into account the aging failure of electric-hydrogen conversion devices. The model aims to minimize the total cost of wind and solar curtailment and electric-hydrogen load shedding. Third, a DPCE-based reliability evaluation method is proposed for EH-IES. This method constructs a DPCE surrogate model using stochastic variable datasets, enabling efficient handling of large-scale mixed random variables without requiring prior knowledge of their probability distributions. This significantly enhances the computational efficiency of EH-IES reliability evaluations. Additionally, the energy supply reliability change rate indices are proposed to quantify the impact of aging failure in electric-hydrogen conversion devices on the overall energy supply reliability of EH-IES. Finally, the simulation analysis using EH-IES based on IEEE-RTS79 validates the correctness and effectiveness of the proposed model and evaluation method.