Effect of IGBT Series and Parallel Combination on Current Transfer Characteristics of DC Vacuum Arc in Hybrid Breaking Process

With the development of DC grids, hybrid DC circuit breaker (HDCCB) has become the research hot-spot for DC interruption. For HDCCB composed of vacuum switches in parallel with IGBTs, the interruption capability is closely related to the current transfer characteristics in hybrid breaking process. The objective of this paper is to determine the effect of different series and parallel combinations of IGBTs on the current transfer characteristics in hybrid breaking process. When the number of parallel IGBTs increases from 3 to 9, the current transfer time decreases from 0.78 ms to 0.60 ms, and the transfer speed increases from 10.46 A/us to 13.5 A/us. As the number of series IGBT groups increases from 1 to 3, the current transfer time increases from 0.66 ms to 1.64 ms, and the transfer speed decreases from 9.45 A/us to 3.8 A/us. The IGBT series and parallel structures influence resistance and the on-state voltage drop of the IGBT branch. As the parallel number increase from 6 to 9, the on-state voltage drop decrease from 10.7 V to 9.8 V. And as the series number of IGBT groups increase from 1 to 3, the onstate voltage drop increase from 7.8V to 23.1V.