A Digital Active Gate Driver for Parallel-Connected IGBTs in Hybrid DC Circuit Breaker Applications

IGBT gate driver is the key component to ensure the stable operation of hybrid direct current circuit breaker (DCCB). A novel digital active gate driver (DAGD) for parallel-connected IGBTs is proposed to provide reliable fault current interruption. The proposed DAGD based on FPGA digital controller take energy from electromagnetic isolated power supply system and reduce the turn-off delay and suppress the voltage spike by variable gate controller. The effect of emitter parasitic inductors on current balancing of parallel IGBTs is analyzed in detail, and effective suggestions are proposed. Finally, the experimental platform for current interruption test is designed and built. The experimental results verify that DAGD cuts off 26.8kA DC current successfully and obtains good effect in parallel current sharing.