A Short Circuit Detection Method for Si/SiC Hybrid Switches

In high-power applications, silicon carbide (SiC) metal oxide semiconductor field effect transistors (MOSFETs) still lack competitiveness against silicon (Si) insulated gate bipolar transistors (IGBTs) due to higher costs and reliability issues. It is anticipated that hybrid parallel switches (HyS) combining SiC MOSFETs and Si IGBTs, which can approach the performance of SiC MOSFETs at a lower cost, will be a better choice. Advancements in SiC MOSFET technology are reducing their specific on-resistance, leading to a further decline in their short-circuit performance, which poses a greater challenge to traditional short-circuit detection and protection methods. This paper proposes a short-circuit detection method for HyS based on gate charge detection. With this method, the short-circuit duration is reduced to 200ns under hard switch fault(HSF) condition, and 300ns. under fault under load (FUL) condition.