Multiport Solid-State Circuit Breaker Topology Based on Bidirectional Devices

Solid-state circuit breakers (SSCBs) offer fast response, arcless operation, and long service life, making them well suited for protection in dc distribution systems. However, when existing SSCB topologies are applied in multiport scenarios, the increase in the number of ports leads to a rise in the number of devices, larger system size, higher conduction losses, and increased overall cost and suffers from low reliability. In this letter, a multiport solid-state circuit breaker topology based on monolithic bidirectional switch (MBS-M-SSCB) is proposed. The proposed topology has a backup protection mechanism that ensures fault isolation even if the monolithic bidirectional switch (MBS) of the faulty port cannot be shut down properly, which improves system reliability. In addition, by employing a shared energy-absorbing branch and utilizing low on-resistance silicon-based MBSs, compared to traditional topologies using unidirectional devices of the same material system, the topology proposed in this letter reduces conduction losses by at least 56% and reduces the use of power devices in the main conduction branch by 50%. Experimental results and comparative analysis confirm that the proposed MBS-M-SSCB offers a compact, cost-effective, and reliable protection solution, well suited for multiport dc systems.