Design and Characteristic Study of a Novel Internal Cooling High Temperature Superconducting Composite Cable With REBCO for Energy Storage Applications

High temperature superconducting magnetic energy storage systems (HTS SMES) have attracted significant attention for fast response and ensure a reliable power supply. However, the current carrying capacity of single superconducting tape often meets limitation for the large scale HTS SMES applied in the power grid. Therefore, a high temperature superconducting composite cable with inner helical cooling tunnel and kA class current carrying ability is proposed for SMES magnet by using REBCO tape. The critical current characteristics of this internal cooling composite cable are analyzed considering the influence of anisotropy in magnetic field. A 100 m length, high temperature composite cable is manufactured in China Electric Power Research Institute (CEPRI). The critical current experimental system with a 3 kA DC current power source and a high-precision Digital Data Acquisition system have been set up to investigate the current carrying ability of a straight and a bending demo composite cable in LN2. The results show that critical current of HTS composite cable consisted of 4 REBCO tapes can achieve 780 A at 77 K self-field and the experimental I-V curve of each REBCO tape in the composite cable is not uniform because of the influence of anisotropy. When the HTS composite cable is bent, its critical current is about 90% of the straight HTS composite cable. Therefore, the design method and the proposed experimental system are proved to be effective as well.