PEMFC water diagnosis using PWM functionality signal and fractional order model

Abstract

This study aimed to develop a new diagnostic technique to determine the hydration status of the proton-exchange membrane fuel cell (PEMFC). The Fouquet impedance model was used to represent the PEMFC impedance, while Laplace’s method transformed the complex model to a real model of explicit fractional order. The outcome of both models in different operating cases (normal, dry and flooded) were compared and yielded good precision. In addition, the explicit fractional order model was used to represent the impedance of the PEMFC, while the current pulse injection (CPI) method with pulse width modulation (PWM) was used to monitor the hydration status of the PEMFC. The PEMFC hydration state was diagnosed using the frequency analysis of the current signals to observe the frequency spectrum amplitude variation at 50 Hz and 1000 Hz in different cases of operation.

Keywords

• PEMFC
• CPI method
• PWM
• Fractional order model
• Diagnosis
• Hydration