Investigation of Current Mirror Based Overcurrent Protection for 1200V 800A High Power SiC MOSFET Modules

With the increasing popularity of SiC MOSFET modules, new challenges on overcurrent protection arise due to higher current density than Si based counterparts and modules' working in Ohmic region, resulting in faster temperature rise. In this paper, FET current mirror based overcurrent detection is evaluated on 1200V 800A Mitsubishi SiC MOSFET Module, with standard IGBT gate drive IC De-Saturation (DeSat) function. A gate driver board is designed utilizing gate current limiting soft turn-off (STO) to turn off gate during overcurrent. Design is experimentally tested under different turn-off currents and operation temperatures. Performance is evaluated and compared with two-stage shutdown (TSS) protection. Experimental results demonstrate the protection effectiveness of both designs and factors that affect the performance.