Pulsed Overcurrent Capability of Power Semiconductor Devices in Solid-State Circuit Breakers: SiC MOSFET vs. Si IGBT

Solid-state circuit breakers (SSCBs) determine a unique pulsed overcurrent operating profile for power semi-conductor devices. In SSCBs, the device pulsed overcurrent capability serves as one of the most critical parameters, yet it remains unclear. This work proposed an electrical-thermal modeling framework to explore the full potential of device overcurrent capability, considering device parasitic, circuit stray components, and multilayer chip structure. Peak temperature at local hotspot is used as the criterion for device thermal runaway. Similarly-rated SiC MOSFET and Si IGBT are compared to demonstrate the difference between device technologies with respect to circuit behavior, power loss and temperature limit. Both devices are able to turn-off much higher current than the data-sheet value, and SiC MOSFET presents a higher overcurrent capability than Si IGBT. In addition, an early saturation in SiC MOSFET limits the actual pulsed current level. These findings provide critical understandings for device margin and design space in SSCB applications.