Stability Improvement of DC Power System According to Applied DC Circuit Breaker Combined With Fault Current Limitation Characteristics of Superconductivity

In this paper, an inductor-type superconducting fault current limiter (I-SC FCL) in the dc power system is proposed to combine the benefits of an inductor and a superconductor. I-SC FCL minimizes the power burden on a superconductor and maximizes the cutoff performance. The inductor delays the rise of the fault current, and the superconductor limits the maximum value of the fault current. Then, they serve together to protect the circuit before the circuit breaker comes into play. The fault currents, limited by an inductor and a superconductor, are introduced into the mechanical dc circuit breaker (M-DCCB). M-DCCB could perform stably due to low power consumption. Analysis of the cutoff characteristics is carried out using the EMTDC/PSCAD program. As a result, the maximum value of the fault current is limited to approximately 2.6 times lower than the previously proposed M-DCCB. Additionally, a low power is burdened on I-SC FCL due to the delay part.