Testing of a Resistive Fault Current Limiter Component Based on Bi-2212 Bifilar Coil

A shunted bulk Bi-2212 bifilar coil was cooled with liquid nitrogen (77 K) and subjected to controlled fault current tests. Prospective currents achieving 11 kA were limited to about 5 kA (first peak) and to 3 kA (following peaks), under 200–300 V. The Bi-2212 coil was able to withstand several short circuits, showing a fast response and reproducible results. A recovery time of minutes was needed between two successive tests. Therefore, the bulk coil was damaged when the interval between subsequent short-circuits was reduced to 30–60 seconds. The critical current was severely reduced by those last tests and further thermal shock. The bulk coil was cut in transversal and longitudinal sections, in order to evaluate the damages.