Proposal and Analysis of a DC Superconducting Fault Current Limiting Circuit Breaker with Adjustable CLR

This paper suggests DC superconducting current limiting (SCL) circuit breaker (CB) that consists of two mechanical switchs (SWs), adjustable current limiting reactor (CLR) and two superconducting (SC) elements. The suggested DC SCL-CB can have advantage to perform DC fault current limiting and interrupting operation and two SWs’ sequential opening operation comprising DC SCL-CB by control circuit can protect two SC elements from DC fault current as well. Through DC short-circuit tests, SW₁ was confirmed to alleviates the power burden on SC₁ element and lower turn ratio of adjustable CLR was analyzed to be contributed to fast interrupting operation of SW2 by quench of SC₂ element.