Multiport Solid-State Circuit Breaker Topology Based on Bidirectional Devices

Solid-state circuit breakers (SSCBs) offer fast response, arc-less operation, and long service life, making them well-suited for protection in DC distribution systems. However, when existing SSCB topologies are applied in multi-port scenarios, the increase in the number of ports leads to a rise in the number of devices, larger system size, higher conduction losses, increased overall cost and suffer from low reliability. In this paper, a multi-port solid-state circuit breaker topology based on monolithic bi-directional switch (MBS-M-SSCB) is proposed. The proposed topology has a backup protection mechanism that ensures fault isolation even if the 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 monolithic bidirectional switches (MBSs), compared to traditional topologies using unidirectional devices of the same material system, the topology proposed in this paper 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 multi-port DC systems.