EDDY-CURRENT SELF-FIELD LOSS IN BI-2223 TAPES WITH AC TRANSPORT CURRENT

The a.c. self-field loss in Bi-2223/Ag and Ag-alloy tapes with differe nt filament number has been measured in the range 59-2500 Hz. The diff erent loss contributions-hysteretic, eddy current and flux-creep resis tive loss (near I-c) are quantitatively dissociated due to their diffe rent frequency dependence and the broad frequency measurement range. T he relative weight of eddy current losses is found to be inversely pro portional to the applied current ratio - the higher I-p/I-c, the less is their contribution. Shown are the frequency Limits, beyond which ed dy current loss has significant and afterwards governing contribution to the total a.c. loss in self-field. The distribution of power dissip ation in the metal sheath is obtained by software simulation. A compar ison is made between the measured, simulated and theoretically calcula ted eddy current loss. Investigated is the effect of the sheath geomet ry and resistivity in reducing the eddy current loss in the measured a nd simulated tapes. (C) 1998 Elsevier Science B.V. All rights reserved .