An Online Failure Assessment Approach for SiC-based MOSFET Power Modules Using Iterative Condition Monitoring Technique

Characterization and monitoring of the faults in Wide Bandgap-based power modules are the prerequisites to achieve robust and reliable high density power electronic design. Due to the basic differences between wide bandgap and Silicon - based power modules, applying the existing condition monitoring approaches - which are mostly designed for Silicon-based devices - does not necessarily provide the expected accuracy in these circuits. Comprehensive and accurate reliability assessment can be addressed using condition monitoring techniques, specialized for wide bandgap-based devices. Real-time observation of the switch junction temperature, as the main failure indicator, is considered in this paper, and it has led to a more accurate estimation of the switch failure rate. In this paper, employing an iterative failure rate assessment with the capability to monitor the device condition and renew the assessment in specific time intervals has addressed the required condition monitoring criteria in wide bandgap-based devices. A coupled simulation platform, consisting of PLECS, COMSOL, and MATLAB is developed to obtain the switch operational parameters during an iterative realtime process. Bayerer lifetime model is employed to estimate the switch failure rate based on the real-time switch parameters. The developed real-time iterative condition monitoring technique is tested for a 1200V/50A SiC MOSFET power module as the case study. DSPACE is employed in the experimental setup as a high bandwidth signal interface, and it was shown that by employing the proposed condition monitoring technique, the switch failure rate can be acquired based on a real-time process in order to achieve more accurate reliability assessment during the switch operation.