The Two-Dimensional Short-Circuit Detection Protection For SiC MOSFETs in Urban Rail Transit Application

Abstract

This article is an extension of our research, which was presented at the PCIM Europe conference in Nuremberg 2019. After proving the potential of the two-dimensional (2-D) short circuit detection method for SiC mosfet s in the preceding work Hofstetter et al. , this article presents the use of the protection system in an urban rail transit application. This introduces many challenges. It is shown how to calibrate the detection system when facing the challenge of different Miller plateaus due to temperature and dc-link voltage ranges and charge carrier trapping effects. Additionally, the effects due to parallelization are examined. False detections due to drain current oscillation are prevented with a simple additional circuit, which is used to suppress the oscillation from the detection circuit. This method leads to a minor increase in current until detection in a short circuit type 2 event. All the techniques and circuitry are experimentally verified and validate the 2-D short-circuit protection as a perfect candidate for the use in urban rail transit application.