Two-stage optimization scheduling method of IES with power-to-hydrogen production system incorporating PEME internal degradation mechanism

Fluctuations in electrolysis power within a power-to-hydrogen (P2H) production system accelerate the degradation of the proton exchange membrane electrolyzer (PEME). To address this issue, a two-stage optimization scheduling method is proposed to smooth power fluctuations by considering the internal degradation mechanism of PEME. Firstly, a PEME temperature control model incorporating electrical and thermal energy feedback from renewable energy sources (RESs) is developed based on thermodynamic characteristics. This model increases the PEME operating temperature through energy feedback, thereby improving electrolytic reaction and hydrogen production efficiency. Secondly, an internal degradation model for the PEME is established based on multiphysical parameter coupling. This model simultaneously accounts for the effects of dynamic current, voltage, and temperature on two degradation pathways, including membrane and catalyst degradation, so as to quantify the degradation costs and improve the lifespan of the PEME during optimal operation. Furthermore, a two-stage optimization scheduling method for integrated energy systems (IES) is proposed by incorporating the PEME internal degradation mechanism and the combined heat and power (CHP) with an adjustable heat-to-electricity ratio, aiming to smooth the power fluctuations of PEME and improve the economic efficiency of the system. Finally, extensive test results verify the effectiveness of the proposed method in terms of balancing the system's economy and the lifespan of the PEME.