New DC Solid-State Circuit Breaker With Natural Charging Operation

Recently, with the development of renewable energy such as solar power and wind power, the dc grid has garnered attention and the dc circuit breakers essential to the dc grid have been actively studied. The dc solid-state circuit breaker (dc SSCB) can quickly break the fault current within 1 ms compared with a mechanical circuit breaker, which does the same in several tens of milliseconds. The previous thyristor dc SSCB cannot naturally charge the commutation capacitor for fault current breaking, and thus its control of operation is complicated. Thus, this article proposes a new thyristor dc SSCB, which can naturally charge the commutation capacitor without complicated switching operation. It can not only perform the fast breaking of fault current, but also the operating duties of reclosing and rebreaking. The operating characteristics of the proposed dc SSCB are verified by the experimental results.