Effect of Ferromagnetic Substrates on ac Losses in YBCO Coated Conductors

Effect of Ferromagnetic Substrates on ac Losses in YBCO Coated Conductors P. M. Grant, (Electric Power Research Institute) N28.002: 8:12 14 March 2001

Coated ConductorsGeneration II Wire • Biaxially Oriented Y-123 • Out of Japan, LANL, ORNL • DOE/Industry Alliance to Commercialize I H

YBCO YBCO 1 m 1 m I I 0.5 m 0.5 m YSZ + CeO2 YSZ + CeO2 H Cross Section Nickel 50 m H

0 dx’ dBx(x,z) = Jz 2 (x-x’)2 + z2 Biot-Savart z B  r z y Jdx’ x   -a a x’ x Jdx’ -a a dx’ 0 (x-x’) dx’ - dBz(x,z) = J 2 (x-x’)2 + z2

] [ 0 1 Bx(x,z) = J - z 2 x+a x-a ) ) tan-1( tan-1( z z [ ] (x-a)2 + z2 ln (x+a)2 + z2 Field Equations 0 1 Bz(x,z) = J 2 2

Field Distribution a = 2 mm J = 25 A/mm

B BS  H -HC 2f 0 BS HC H > HC ; P = Hysteresis 2f H2 H < HC ; P = 0

Loss • HC = 80 Oe • BS = 6000 Gauss • = 75 P = 0.14 W/m Measured ac Losses Y-123 cc on Hastalloy (non-magnetic) = 0.48 W/m (Ciszek, et al.)

Conclusions “Spending a nickel does cost you something even these days”

Effect of Ferromagnetic Substrates on ac Losses in YBCO Coated Conductors