kA class resistive fault current limiting device development using QMG HTC bulk superconductor

kA class HTC bulk superconducting elements of devices for a resistive type fault current limiter for 6 kV distribution networks have been developed and tested The YBCO devices made with the quench melt growth method has 20,000 - 30,000 A/cm(2) critical current densities at 77 K and 1 T determined by the 1 mu V/cm criterion for the current flow parallel to the a-b plane. The QMG device has 5 Cin-m normal state resistivity and an n-value of approximately 6 for the same direction of current flow. An element of the device with a 1.5 x 1.5 mm(2) cross-section with silver electrodes formed by sputtering could successfully carry exceeding 2,200 A(peak) a.c. transport current in self field at 77 K.