Effects of Single Narrow Neck of SUS Layer on AC Current-Limiting and Interrupting Characteristics of Superconducting Fuse

High temperature superconductor (HTS) can be used to limit and interrupt fault current as a fuse. However, the narrow neck on the side of the tape causes lower and unstable critical current, which makes its application difficult. In this paper, we proposed a new type of superconducting fuse with a narrow neck manufactured in a stainless-steel (SUS) reinforcement layer, which can hold the critical current and enhance the fusing ability. An experimental model was established with an impact source. The AC current limiting and fusing tests were conducted with the new superconducting fuse and the fuse without a narrow neck. Experimental results show that compared to the fuse without a narrow neck, the new superconducting fuse achieves a reduction of at least 40 A in peak current, an increase of at least 77.4% in arc voltage, a decrease of at least 17% in front arc I^2t, and a shorting of at least 0.872 ms in pre-arcing time. The superior current-limiting and fusing capabilities of the new superconducting fuse can help protect superconducting devices during fault conditions.