Design and Verification of a Novel Thyristor-Based SSCB With Ultrafast Current Suppression Capability

Since thyristors have better performance than fully controllable devices in terms of on-state resistance and cost, designing thyristor-based solid-state circuit breakers (TSCBs) to protect dc microgrids has become gradually popular. In this article, a new bidirectional TSCB with four significant advantages is proposed. First, it could reliably and actively interrupt both the operating and fault currents with simple operation sequences; thus, ensuring high reliability and controllability. Second, the currents at input and output sides of the proposed TSCB are rapidly suppressed immediately after it starts working, so the source or load sides will not be threatened by large surge currents. Third, both the auxiliary thyristors and capacitors in the proposed TSCB will automatically restore to their initial states after the current breaking processes, which ensures the proposed TSCB has a reclosing protection function. Fourth, it has a low conduction loss, and is therefore effective. All these advantages make the proposed TSCB one great candidate to protect dc microgrids. The detailed topology introduction, circuit modeling analyses, experimental results, and comparative study are presented.