A Novel Online Diagnosis Method for Tubular Solid Oxide Fuel Cells Using Total Harmonic Distortion Analysis

Abstract

Fast and accurate online prognostic technology is urgently needed for the long-term and stable operation of solid oxide fuel cell (SOFCs). Total harmonic distortion analysis (THDA) is a potential candidate that obtains the dynamic information of an electrochemical system by analyzing high-order signals and has been successfully utilized in PEMFC fault diagnosis. In this study, the THDA method is utilized in a tubular SOFC under fuel and air starvation conditions at different hydrogen and air flow rates. The total harmonic distortion spectra are obtained in the frequency range of 0.1~100 Hz. The effects of different excitation current amplitudes on the results accuracy are further investigated. As a consequence, the excitation amplitude range, frequencies with high sensitivity and appropriate threshold are chosen to diagnose different faults efficiently.