A Fast Short-circuit Protection Method for High-voltage and High-power SiC MOSFET

SiC MOSFET has weaker short-circuit tolerance, which requires higher demand on the rapidity and reliability of short-circuit protection. Most of the existing methods mainly adopt single electrical parameter, and are focused on low-voltage and low-power SiC MOSFET. However, with the increase of voltage and power level, device characteristics are significantly different, which makes it difficult to achieve fast and reliable protection for high-voltage and high-power SiC MOSFET by simply applying previous designs. Firstly, this paper conducts a detailed study on several common short-circuit detection methods. Secondly, based on the device characteristics of high-voltage and high-power SiC MOSFET, this paper deeply compares the applicability of different short-circuit detection methods. Next a new method based on multiple electrical parameters is proposed, which starts-up short-circuit fault protection firstly and then accelerates subsequently. Finally, an experimental platform is built to verify the feasibility of the proposed method. The results show that the proposed method not only realizes the reliable identification of hard switching faul (HSF) and fault under load (FUL), but also balances the response speed of short-circuit protection.