부산대학교 도서관

The superconducting current limiter could bring a solution to a problem not satisfactory solved: the limitation of fault currents under high voltages. We carry out a research and development program based on bulk bismuth materials. They are attractive due to their homogeneous quench into the resistive state and after the normal state even if their critical current densities are not very high (several MAm/sup -2/ at 77 K, self field). They limit efficiently currents without any risk of burning (no hot spots) even under high electrical fields. These materials are elaborated in the form of Bi-2223 bars formed by an isostatic pressure and classical sintering. Sixty bars (/spl phi/=4 mm, /spl Lscr/=120 mm, I/sub c/=35 A) were assembled. This assembling was tested up to 1100 V at 1080 A instead of a theoretical value of 5000 A. The superconductor was exposed to a maximum power density of 12 GW/m/sup 3/ without damage. We present the measurements obtained on the bars and their assembly.