Current limitation with bulk Y-Ba-Cu-O

The fault current limiter is a very attractive device for electric networks . Meander pattern conductors cut from bulk melt textured YBCO were studied for this application. The meanders are put in series and/or in parallel to match the required current and voltage. The YBCO materials are attractive b ecause they show a very effective limitation with a relative low volume (hi gh engineering current density and normal state resistivity). However, they are sensitive to hot spots. To avoid these destructive hot spots the opera ting temperature is chosen very close to the critical temperature (above 90 K). This temperature range is reached using a pressurised liquid nitrogen bath. Working close to Te has two major advantages. The first is reduced va lues of Jc which limit the power dissipation. The Jc can be matched by chan ging the pressure on tile nitrogen bath. The second is that the proximity o f the normal state is favourable for homogeneous quenches along the whole m eander as it can be experimentally recorded. Results obtained on single mea nders and on the whole assembly are reported under steady state operation a s well as during no current limitation. Forty three meanders in series Limi ted the current to 740 A (11 000 A unlimited value) under 1 kV.