Characterization of low and high frequency phenomena in a PEM fuel cell using singularity analysis of stack voltage

Abstract

The aim of this work is to propose a new development of the fuel cell characterization tool based on Voltage Singularity Spectrum (VSS), a pattern that can advantageously be estimated from the "free" evolution of the stack voltage. A Polymer Electrolyte Membrane Fuel Cell (PEMFC) designed to operate in micro Combined Heat and Power units is investigated to create an experimental database made of normal and abnormal operating conditions. Some VSS signatures based on Wavelet Leader Multifractal Analysis (WLMA) are computed on low-and high-frequency filtered stack voltage signals reflecting different physical phenomena dynamics. The resulting low-and high-frequency VSScomputed for six different operating conditions are then compared to the Electrochemical Impedance Spectra (EIS) recorded in the same conditions. In this way, we intend to establish some links between the VSS patterns and the EIS based on well-known physical analyses. We also show that the dominant singularity strengths of the low (and possibly also high) frequency VSS can be considered as relevant clustering features to identify various PEMFC operating states (linked with poorer / better air diffusion, with lower / higher MEA hydration), as it is usually done with the use of the characteristic resistances intercepted on the EIS graph x-axis.

Design, Development and Testing of a Monitoring System for the Study of Proton Exchange Fuel Cells and Stacks

“…With this tool, they managed to obtain the current and voltage of the stack as well as measure these parameters at the battery, motor, and DC converter. Benouioua et al [20] proposed the development of a fuel cell characterization tool based on singularity spectrum voltage (VSS), a pattern that can be estimated by the evolution of the voltage of the cell, as indicated in [21]. In this study, the authors obtained and verified system state indicators under different modes of operation (linked with better or worse air diffusion, and with higher or lower membrane hydration).…”

Dynamic Fractional-Order Model of Proton Exchange Membrane Fuel Cell System for Sustainability Improvement

“…To develop diagnostic strategies for the new mCHP PEMFC application, aimed at preventing operational faults and enhancing the durability of the PEMFC system, experiments were conducted using the experimental test bench detailed in [46]. The adopted mCHP PEMFC system is designed by Riesaer Brennstoffzellentechnik GmbH and Inhouse Engineering GmbH, Germany [46]. The mCHP PEMFC system incorporates a stack of 12 PEMFC cells.…”

“…Air is directed to the cathode inside the stack, and an anode receives a fuel mixture with a composition of 75% H 2 and 25% CO 2 , emulating the reforming process of natural gas. Details on the stack's characteristics and nominal operational parameters can be found in Table 2 [46].…”

A Comprehensive Review on Condition Monitoring and Fault Diagnosis in Fuel Cell Systems: Challenges and Issues

“…One of the most studied diagnostic techniques involves measuring the individual stack voltage and accompanying the voltage difference between them and the time evolution [142,143]. Other techniques involve more invading methods such as Impedance Spectroscopy (EIS) [144,145], while others opt for more model-based techniques through the use of residuals and hysteresis windows [91,145,146] or even datadriven [147,148] and signal processing tools [149][150][151][152][153][154].…”