The Influence of Local Tapes Misalignment in Stacked YBCO Cable on Its AC Loss

Abstract

When calculating the AC loss of REBa2Cu3O7−x (REBCO, RE = rare earth) coated conductor cable with stacked geometry, it is often considered that the tapes in the cable is perfectly stacked (there is no transverse misalignment of the tapes). However, the actual stacked cable will have transverse misalignment. The influence of transverse misalignment of tapes on the AC loss of the whole cable needs to be studied in order to understand the actual situation. In this paper, the 2-D H formulation calculated the AC loss of the cable with 10 tapes stacked in three cases. In the first case, the cables are perfectly stacked without lateral misalignment between the tapes. In the second case, the tapes of the cable are oblique to one side. In the third case, the tapes are disordered with each other. The result shows that under the transport current at 50 Hz, when the transport current is less than 0.75Ic0, the transport loss of the cable with obliquely stacked cable is more than the perfectly stacked cable, and when the transport current is greater than 0.75Ic0, the transport loss of the perfectly stacked cable is slightly larger than the obliquely stacked cable. Moreover, the transport loss of disorderly stacked cable is more than perfectly stacked cable at 50 Hz. When the transport current amplitude and the misalignment distance between the tapes in the cable are constant, the transport loss of obliquely stacked cable and disorderly stacked cable relative to perfectly stacked cable both increases first and then decreases as the frequency increases. Under the 50 Hz magnetization field, the magnetization loss of the perfectly stacked cable is less than the cables with oblique misalignment and disorder misalignment. When the amplitude of the external magnetic field and the misalignment distance between the tapes in the cable are constant, the magnetization loss of obliquely stacked cable and disorderly stacked cable relative to perfectly stacked cable also increased first and then decreased as the frequency increased.