Analysis of the Electro-Magnetic Properties of CORC Coil Considering Joint Resistance

Wounded with second-generation (2G) high temperature superconductors (HTS) tapes, the conductor on round core (CORC) coil exhibits notable benefits such as low AC loss, powerful current-carrying capability, and great mechanical properties, which makes it one of the optimal materials for high magnetic field generation in the engineering applications for fusion magnets. However, it is challenging for current manufacturing techniques to ensure the uniformity among the joint resistances of HTS tapes in CORC coils. And it will have a crucial impact on the electro-magnetic properties of CORC coils. Therefore, a three-dimension (3D) finite element model of CORC coils considering joint resistance is established, and the effects of joint resistance on the coils’ current distribution and AC losses are analyzed. Results show that during AC operation, uneven joint resistances and reactance arising from the coils’ helical winding structure will act together on the current among HTS tapes, causing non-uniform current distribution and increasing the total AC losses of CORC coils. Additionally, the uneven degree of the joint resistance raises the CORC coil’s overall AC loss.