Title :
AC transport characteristics of QMG elements for fault current limiting devices
Author :
Yang, C. ; Miura, O. ; Ito, D. ; Morita, M. ; Tokunaga, T.
Author_Institution :
Tokyo Metropolitan Univ., Japan
fDate :
6/1/1999 12:00:00 AM
Abstract :
To study the quenching behavior of a HTSC YBa/sub 2/Cu/sub 3/O/sub 7-/spl sigma// pseudo single crystal bulk superconductor (QMG) as a resistive type fault current limiting device, the E-J characteristics, n-value and propagation velocity of the flux flow state and the resistive state of the QMG elements at 87 K were measured. The n-values, which varied from 5.4 to 7.3 at 87 K, were obtained for the QMG which has 1.6/spl times/10/sup 3/ A/cm/sup 2/ critical current densities at 87 K in 250 G. Based on the heat transfer characteristics between the QMG elements and coolant, the quench propagating velocity of the element in liquid argon is discussed.
Keywords :
barium compounds; copper compounds; critical current density (superconductivity); fault current limiters; flux flow; heat transfer; high-temperature superconductors; superconducting devices; thermal analysis; yttrium compounds; 250 G; 87 K; AC transport characteristics; E-J characteristics; HTSC fault current limiting devices; QMG elements; YBa/sub 2/Cu/sub 3/O/sub 7-/spl sigma//; YBa/sub 2/Cu/sub 3/O/sub 7/; critical current densities; flux flow state; heat transfer characteristics; liquid argon; n-value; propagation velocity; pseudo single crystal bulk superconductor; quench propagating velocity; quenching behavior; resistive state; Argon; Coolants; Critical current; Critical current density; Current measurement; Fault currents; Pulse shaping methods; Shape; Space vector pulse width modulation; Voltage;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
