Reduction Effect on Magnetization Loss in the Stacked Conductor With Striated and Transposed YBCC Coated Conductor

Abstract

Recently, it is proposed to make striations on the YBCO coated conductor and to transpose each other as one of the solutions to decrease the perpendicular magnetization loss. For large power application using HTS, the stacked conductor packing the YBCO coated conductors should be used because the current carrying capacity of a single conductor is limited. The stacked conductor has different AC loss characteristics from single conductor because the screening currents in the adjacent conductors affect the local magnetic field at the position of each conductor in the stacked conductors. In this paper, we research the effect by the stack, striation and transposition on magnetization loss of YBCO coated conductors in perpendicular magnetic field. To estimate the reduction effects of perpendicular magnetization loss, several short samples as the stacked conductor with striation and transposition are prepared and tested. We compare the measured results of the conductors with that of the single YBCO coated conductor to estimate the reduction effects.

Simulation of ac loss in Roebel coated conductor cables

“…Both methods are already prepared for this [15,16], but such simulations are only possible after extensive measurements on single tapes in order to extract the field and position dependences of the critical current density. Future simulations should also take into account the effect of striations in the strands [4]. Finally, it is also necessary to predict the coupling loss in Roebel cables [5,9].…”

“…Moreover, these cables have a complex transposed structure. As a consequence, the interpretation of ac loss measurements is not straightforward [2,[4][5][6][7][8][9]. Simulations in a previous work of ours have been useful for predicting and understanding the measured loss mechanisms for either transport and magnetization loss [6].…”

“…the unknowns of the problem). In fact, in both methods the superconducting strands are assigned 100 degrees of freedom 4 , so that the total number of degrees of freedom associated to the superconductor is 1400 (100 times the 14 strands). But whereas in the MMEV method this also constitutes the number of DOFs of the whole problem, in the FEM case it only constitutes a small part of them: in fact, the total number of DOFs is as high as 35 658, and most of them come from the mesh of the air region between the strands.…”

Numerical simulations of the angular dependence of magnetization AC losses: coated conductors, Roebel cables and double pancake coils

“…As a consequence, they may not be representative for the present nanoengineered material [16][17][18]. For Roebel cables there are also measurements for perpendicular applied fields [20,33,7,27], parallel fields [34] and transport currents [20,35].…”

“…In this case, it is still desirable to reduce the AC losses because they limit the ramp rate and generate significant hysteresis losses, especially for liquid helium cooled magnets. Roebel cables [3][4][5][6][7] reduce the AC losses caused by both components of an external magnetic field [4,5,8]. In spite of the progress in Roebel cables, many aspects of their AC losses remain unknown [2].…”