ABSTRACT Gate oxide layer degradation has become one of the key issues in the reliability of SiC MOSFETs, which seriously restricts the broad application of SiC MOSFETs. Existing research is primarily based on the threshold voltage or gate leakage current, as well as other parameters, to indicate the degradation of the gate oxide layer. However, these methods generally have limitations, including high hardware requirements and difficulties with online experiments, which make it challenging to implement online detection under inverter operating conditions. In this paper, a novel online detection method of gate oxide layer degradation based on the drain‐source surge voltage ( V surge ) is proposed. Moreover, this paper analyses the relationship between the V surge and the mechanism of gate‐oxide layer degradation and designs a V surge extraction circuit. Combined with the HTGB experiment, the effectiveness of the dynamic monitoring strategy is verified in the inverter system. The experimental results show that the proposed method can accurately online identify the ageing state of the gate oxide layer under a 300 V inverter.
Wang et al. (2026) studied this question.