A method for online ageing detection in SiC MOSFETs

This paper presents a comprehensive study on degradation monitoring of SiC MOSFETs and propose a method to detect incipient faults for early warning in power converters and smart gate drivers. During the accelerated ageing tests (power cycling) several electrical parameters are measured to analyze critical signatures and precursors for early fault detection. Among those, gate leakage current is identified as one of the most practical precursor which exhibit consistent changes throughout the aging and relatively easy to monitor. The proposed method is experimentally justified which can be integrated to a gate driver to monitor the condition of the MOSFETs. This method naturally fits to the applications which cannot tolerate interrupts caused by unpredicted failures. Due to its simple scheme and low cost, it can potentially be embedded into commercial gate drivers featuring improved reliability options.