On-Line Digital Fine Monitoring of SiC MOSFET Gate-Oxide Health: A Dual-Channel Gate Driving Approach

SiC power MOSFETs, compared to their Si counterparts, still lack maturity, hindering their adoption in aeronautical applications. Consequently, there is a growing need for the development of smart gate drivers with built-in functions like health monitoring. Reducing failures and downtime in power converters relies on an early detection of component ageing. However, assessing reliably the health condition of power transistors in PWM operation remains a challenge. In this perspective, a non-invasive strategy is proposed. This approach aims to determine precisely and accurately the health state of the gate oxide of a SiC power MOSFET. It uses a dual-channel gate driver to trigger a slow turn-on event and clean switching measurement within a PWM frame. This method involves an online tracking of oxide ageing, or charge-trapping indicators present in the gate signal waveform.