An Observer-Based Switch Open-Circuit Fault Diagnosis of DC-DC Converter for Fuel Cell Application

The power semiconductor device is one of the most fragile components of the dc–dc power converters in industrial applications. In this article, a Luenberger observer-based switch fault diagnosis method is proposed for the dc–dc interleaved boost converter for fuel cell (FC) application. The inductor current within the main controller system is selected as the diagnosis variable, avoiding the use of extra sensors. Moreover, an adaptive threshold is introduced to deal with the effects of the converter circuit parameter uncertainty, and the converter operation point variation resulted from FC nonlinear volt-ampere characteristic. The proposed fast fault diagnosis method shows good robustness to false alarms. The simulation and experiment results demonstrate the robustness and validity of the proposed method.