Observer-Based Robust 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 paper, a Luenberger observer-based switch fault diagnosis method is proposed for the DC-DC interleaved boost converter (IBC) for fuel cell (FC) application. The diagnosis variable is the inductor current, which is within the main control system, without needing extra sensors. An adaptive threshold is used to avoid the effects of the converter modeling imperfection, and the wide converter operation range due to FC nonlinear volt-ampere characteristic. The proposed fast diagnosis method is robust to the converter parameter uncertainty and external disturbance. The simulation and experiment results validate the effectiveness and robustness of the proposed diagnosis method.