A Novel Assessment Method of Gate Oxide Degradation Based on IGBT Turn-on Losses for On-Line Reliability Monitoring

Insulated gate bipolar transistor (IGBT) is the core device of medium and high power converter, it widely used in new energy power generation, rail locomotive traction, electric vehicle drive, aerospace and other important fields, its operation reliability is great significance to ensure safe, reliable and efficient operation of the system. The gate oxygen layer is a relatively weak link with IGBT. Firstly, this paper analyzes the gate oxygen degradation mechanism of IGBT. Secondly, the influence of degradation fault of gate oxygen layer on the turn-on characteristics of IGBT is analyzed. Then, the simulation method of degradation fault of gate oxygen layer of IGBT is studied. Finally, based on the previous basis, the concept and monitoring method for characterizing the evolution of IGBT gate oxygen degradation by using the turn-on losses (Eon) is proposed, and verified by simulation and experiment. This method has the advantages of convenient measurement (no contact with IGBT), high accuracy and is suitable for on-line reliability condition monitoring and evaluation, it has important application value for the operation and maintenance and state prediction of power electronic devices and equipments.