並列接続されたSiC-MOSFETの電流アンバランス条件下における高速短絡保護の検討

抄録

This paper proposes methodology and gate drive circuit that can immediately detect short-circuit (SC) of multi-paralleled SiC-MOSFETs even under current imbalance condition. Proposed method detects SC current using an integration circuit that can sense di/dt. The detection level of SC current can be adjusted to a desired value regardless of the number of SiC-MOSFETs connected in parallel. The effectiveness of the proposed approach was experimentally validated for four-paralleled SiC-MOSFETs under extreme current imbalance in SC condition. SC was detected within 0.5µs and all SiC-MOSFETs were protected without destruction at most 2.2µs after the onset of SC, for all types of SC 1, 2 and 3.