New open circuit fault detection in a DC-DC converter

The fault detection in power converters is a meaningful aspect to ensure the system's power quality. In this context, the open circuit fault (OCF) in power switches is increasingly discussed. This paper proposes an OCF detection method that triggers the power switches based on the slope of the output predicted voltage. The proposed algorithm allows a sensorless detection of the OCF. The regulator synthesis uses the transfer function for a small signal model. The efficiency of the prediction method is validated by an estimation of the output voltage for several duty cycles offering a good accuracy, in which the error does not exceed 5%. The validity of the proposed method is demonstrated by MATLAB/Simulink tools and a comparative analysis is given at the end of this paper. Compared to other works in the literature, the major advantage of the proposed method is the simplicity of implementation, lower cost, and a better OCF detection time, which does not exceed 15% of the switching period in the test conditions.