Real-time aging monitoring for power MOSFETs using threshold voltage

Power MOSFET is one of the most rapidly aging components in power electronic converters, and some study of the health monitoring of power MOSFETs is made in this paper. This paper proposes a threshold voltage-based real-time aging monitoring method for power MOSFETs in Buck converters. Firstly, the origins of degradation in power MOSFETs are analyzed, and the junction temperature is indicated to be the most promising failure precursor for the health monitoring. Then, threshold voltage is chosen as the thermo-sensitive electrical parameter for junction temperature estimation. For Buck converters, a real-time threshold voltage monitoring method is proposed. Taking advantage of the particular structure of Buck converters, the proposed method only needs to capture the gate-ground voltage, which is costless and easy to realize. Finally, the effectiveness of the proposed method is verified by simulation and experimental results.