Research on Overcurrent Interruption Capability and lnfluencing Factors of SiC MOSFETs in DCCBs

Abstract:
As critical components in OC systems, OC circuit breakers (OCCBs) are designed for rapid fault isolation and short-circuit current interruption, where SiC MOSFETs emerge as a pivotal semiconductor solution. In this paper, the maximum overcurrent interruption capabilities of planar, asymmetric and double trench SiC MOSFETs are systematically compared, with three influencing factors analyzed for their impact on OCCBs applications. To achieve this, a customized experimental platform emulating practical OCCB conditions is developed, where critical parameters are evaluated under dynamic faults through con trolled modulation of experimental variables. Experimental results indicate that asymmetric and double trench OUTs offers higher current conduction density, highlighting the benefits of trench design in enhancing channel density and reducing RoN,sp. The double trench OUT exhibits the highest current interruption capability, followed by the planar OUT, while the asymmetric trench OUT shows the lowest performance due to its smaller active area and concentrated heat dissipation. Meanwhile, the study identi­ fies on-state resistance RoN and saturation current fsat as the key limiting factors for overcurrent interruption capability. The overcurrent performance is shown tobe improved to different extents by increasing gate voltage, reducing operating temperature, and minimizing on-state duration, which are attributed to reduced RoN and enhanced fsat.