A Study on Increasing the Capacity of Transformer-Type Superconducting DC Circuit Breaker

Superconducting Fault Current Limiter (SFCL) can increase the fault current-limiting rate through the series connection of superconducting elements, and through this, it can be applied to systems with high capacity. However, when multiple superconducting elements are connected in series, unbalanced quench characteristics may occur continuously due to problems of critical characteristics and partial quenching. We have proposed a quenching method of balanced SFCL using the neutral line to solve this problem. In this paper, we applied several superconducting elements with the neutral line to increase the current-limiting rate of the transformer-type superconducting current limiter module (T-SFCL module). In addition, when the T-SFCL module was combined with the DC circuit breaker, the operating characteristics of the superconducting DC circuit breaker were confirmed. As a result, power consumption of superconducting elements was balanced due to the balanced quench of superconducting element, and fault current was reduced due to the high current limiting characteristics of superconducting element.