A study on increasing the capacity of transformer-type superconducting DC circuit breaker

Superconducting Fault Current Limiter (SFCL) can increasethefaultcurrent-limitingratethroughtheseriesconnection of superconducting elements, and through this, it can be applied to systems with high capacity. However, when multiple superconduct-ing elements are connected in series, unbalanced quench character-istics may occur continuously due to problems of critical character-istics andpartialquenching.Wehaveproposedaquenching method ofbalancedSFCLusingthe neutrallinetosolvethisproblem.Inthis paper, we applied several superconducting elements with the neu-trallinetoincreasethecurrent-limitingrateofthetransformer-type superconducting current limiter module (T-SFCL module). Inaddi-tion, 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 tothe balanced quench of superconducting element, and fault current was reduced due to the highcurrentlimitingcharacteristics of superconducting element.