Diagnosis of PEM Fuel Cell Stack Based on Magnetic Fields Measurements

Non-uniform current density distribution in PEM fuel cell results in local over-heating, accelerated ageing, and lower power output. This paper proposes a diagnosis approach for PEM fuel cell system based on monitoring the current density distribution inside the stack. A magnetic sensor network has been used to provide an image of the current density distribution. The diagnosis method has three steps: residuals generation, residual analysis to obtain symptoms and decision by classifying these symptoms. The proposed approach has been applied on virtual measurements and validated on experimental measurements under performance degradation due to long term functioning of the PEM fuel cell stack and under low air stoichiometric ratio due to an actuator fault. Results show that the proposed method is a remarkable tool for diagnosis and taking compensatory actions.