面向直流微网的磁耦合双向 Z 源固态断路器建模与设计

DC microgrids are attracting increasingly widespread attention for their high efficiency, simple control, and superior power quality. To ensure the safe operation of DC microgrids, this paper proposes a novel magnetically coupled bidirectional Z-source solid-state circuit breaker (BZSCB) and its model-based optimization design method. The novel BZSCB has the characteristics of source-load co-grounding and easy configuration of fault protection thresholds. The working principle of the novel BZSCB is described in detail, and a full-fault transient accurate modeling method considering the reverse recovery demand of the thyristor is proposed, which can provide effective guidance for the circuit breaker component selection and the optimal design. Furthermore, an auxiliary tripping branch is integrated into the novel BZSCB to implement the functions of comprehensive protection and load switching. The influence of line parasitic inductance on the performance of the circuit breaker is also analyzed. Finally, the effectiveness of the proposed topology and the accuracy of the modeling method are verified by simulations and a 270 V/1.5 kW experimental prototype.