AC loss characteristics of CORC^®cable with a Cu former

Abstract

High-temperature superconductors from the REBCO (RE = rare earth) family have attained industrial production and their performance is continuously being enhanced. However, cabling technology for high-current (kA range) cables for magnet technology is still challenging and there are only few cable concepts available (CORC®, Roebel cable, twisted stack cable). Each of them exhibits different characteristics. In this paper we experimentally investigate CORC® cable produced in-house utilizing a copper tube former. Such a former offers a central cooling channel for partial or complete cable cooling by forced flow of coolant. We focus mainly on AC loss due to transporting AC current, an external applied AC magnetic field and their simultaneous action. In the case of transporting AC current we found indications that a large part of the total loss has its origin in eddy currents due to an axial magnetic field. For the investigation of magnetization AC loss, we prepared several samples with different configurations. In this case we found direct evidence for increasing AC loss due to losses in the metallic former. However, we also found that at low field amplitudes the magnetization AC loss of the complete cable is lower than the loss in the bare former. This is caused by shielding of the magnetic field by a superconductor, which was also confirmed by numerical simulations.

Study of the magnetization loss of CORC® cables using a 3D T-A formulation

“…With a transposition on all the tapes in each layer, the CORC cable approach is effective in reducing the coupling currents in REBCO tapes, as well as magnetization loss. This has been validated experimentally in previous studies [26][27][28][29]. To further reduce the magnetization AC loss, researchers proposed to divide single tapes into multi-filaments [30][31][32][33][34][35][36].…”

Review of the AC loss computation for HTS using H formulation

“…Replotted from [36] model [51]. Terzioğlu et al studied the transport current AC loss and magnetization AC losses (frequency 36, 72 and 144 Hz) of the HTS CORC with a Cu former by experiment and H-formulation method [52].…”

Efficient Numerical Modeling of the Magnetization Loss on a Helically Wound Superconducting Tape in a Ramped Magnetic Field

“…To simulate a CORC cable, the AC losses were simulated at first by a two-dimensional model neglecting the winding of the tapes [12]. Later, an improved simulation study of the magnetization losses in CORC cables was carried out using three-dimensional models based on the H formulation [7], [13]. Simulations with three-dimensional models using the T-A formulation have also been conducted to investigate the AC losses in CORC cables, twisted stacked-tape conductor cables, and double coaxial cables with various transport currents and background magnetic fields [14].…”