Numerical Study on AC Losses of Multi-Channel High Temperature Superconducting TSTC-CICC Conductors

The alternating current (AC) losses of the multi-channel high temperature superconducting (HTS) twisted stacked tape cable-cable in conduit conductor (TSTC-CICC) composed of second-generation (2G) HTS tapes were studied using the T-A formulation and the three-dimensional (3D) finite element method. In this paper, the transport and magnetization AC loss of four-channel TSTC-CICC conductors with two different tapes stacking arrangements (Structure-I and Structure-II) were calculated, in the case that different torsion, transport currents and external magnetic fields. The results show that the transport and magnetization losses of the two types of conductors are positively correlated with the torsion of the conductor, under the condition that the same transport current and external magnetic field. When the torsion of the conductor is the same, the transport losses of the two types of conductors increase with the increase in current, while the magnetization losses enhance with the increase of the magnetic field. When the torsion is 0.06 m, the transport losses of Structure-I are smaller than those of Structure-II in the situation of the same transport current. Under the same external magnetic field conditions, the magnetization losses of Structure-I are higher than those of Structure-II. In presence of the imposed magnetic field, the shielding currents that permeate from the border of the stacked tapes to the middle of the tapes are generated inside the stacked tapes of the conductors, but the distributions of the shielding currents in each channel of the two types of conductors are different.