Circuit Modeling and Experimental Validation of a Bidirectional Z-Source Circuit Breaker Based on Coupled Inductors
Zhongzheng Zhou, Yuqing Fei, Yao Li, Yufeng Wang, Yuyang Liu, Weilin Li
Abstract
DC microgrids have attracted increasing attention due to their high efficiency, simple control, and high power quality; however, circuit fault protection remains a technical challenge. Z-source circuit breakers (ZSCBs) have provided a promising solution with fast, autonomous, and arcless fault clearances. To further provide bidirectional operation capability and enhanced performance, a bidirectional ZSCB based on coupled inductors is proposed and well designed in this paper. It can offer bidirectional power flow and fault disconnections in a compact size. The working principle and circuit analysis are elaborated with mathematical models, which cover the entire fault-clearing transient and can provide insightful guidelines for breaker design and component sizing. Moreover, a crowbar-type switch enabling manual tripping operation of the proposed ZSCB is integrated. Finally, Saber-based simulations verify the effectiveness of the models and the design, which are further validated by a 48 V/230 W laboratory prototype.