Optimization of power allocation for wind-hydrogen system multi-stack PEM water electrolyzer considering degradation conditions

Hydrogen production from wind power has become one of the most important technolo-gies for the large-scale comprehensive development and utilization of wind power, but the randomness of wind power has a large negative impact on the stability and cost of such wind-hydrogen hybrid energy systems. In this work, we initially analyze the relationship between electrolyzer efficiency and degradation with a three-dimensional multi-physics field model of PEMWE single-cell. Optimization of a power allocation strategy for wind -hydrogen system with a multi-stack PEM water electrolyzer (PEMWE) is proposed by considering degradation conditions. The multi-stack PEMWE power allocation strategy consists of the control module and execution module. In the control module, the degra-dation of PEMWE is quantified using the voltage degradation rate under different operating conditions. By setting the turning power point and external power supply and calculating the power allocation order online to reduce the degradation of PEMWE. In the execution module, the extended duty cycle interleaved buck converter (EDCIBC) based on fuzzy PID control is used to power each PEMWE single-stack. Case studies are carried out via com-puter simulation based on the configuration and experimental data for a specific wind farm located in Cixi, Zhejiang, China. Our results show that the energy efficiency of the wind -hydrogen system is 61.65% in a one-year operation, the voltage degradation of the PEMWE single-stack is 7.5 V, and the maximum efficiency is 6.29% lower than that when it is not aged. The EDCIBC output current ripple is as low as 0.053%, which rapidly and accurately follows the generated power allocation signal.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this study, an optimization method for power allocation in a wind-hydrogen system based on multi-stack PEM water electrolyzers is proposed to reduce degradation by considering degradation conditions. The results show that the energy efficiency of the wind-hydrogen system is 61.65% in a one-year operation, with a voltage degradation of 7.5 V in the PEMWE single-stack and a maximum efficiency 6.29% lower than that when it is not aged. The proposed power allocation method achieves low ripple output current and accurately tracks the power allocation signal.