Asynchronous Control Method of Parallel IGCT Components in Hybrid DC Circuit Breakers

Hybrid DC circuit breakers (HDCCB) based on high-power full-control semiconductor devices have attracted extensive attention and research for their large current conduction and fast current breaking capability. The IGCT device possesses a strong surge current withstand capability and low on-state voltage drop, making it a promising full-controlled semiconductor candidate. To meet the requirements of the increasing DC power capacity, the current turn-off capability of DC circuit breakers must be improved, this paper studies the power electronic switch based on parallel IGCT devices. Firstly, the modular IGCT component circuit topology which is easy to be series connected is proposed, and the mechanism analysis of the parallel current distribution imbalance is carried out. The single-stage laboratory prototype is built up to study the switch on-off characteristics. To promote the parallel current distribution effect, an asynchronous control method is proposed, and the control effects of different time differences are studied. Finally, the validity and feasibility of the differential control are verified by experiments.