Nonlinear Diffusion Analysis of the Voltage Signal of a Polymer Electrolyte Fuel Cell

摘要

In polymer electrolyte fuel cells (PEFCs), cathode water accumulation can have negative effects on fuel cell performance if not properly managed. In order to further understand the nonlinear and oftentimes chaotic dynamics associated with cathode water generation and removal, we apply a nonlinear analysis to the PEFC voltage signal. We examine scale invariance in the frequency power spectra of the fuel cell voltage signal at varying current densities. We also estimate the Hurst exponent of the PEFC voltage with a diffusion analysis. We find that both the scale invariance and the Hurst exponent are able to indicate differences in the dynamics from cathode microchannel flooding. The results are applicable to PEFC water management.