Simulation of Inductance Effect in Current Distribution for Simple-Stacking HTS Cables
GARFIAS Davalos Diego Armando （SOKENDAI）； 成嶋 吉朗, 柳 長門 （NIFS）
Abstract:To develop a high-current High-Temperature Superconducting (HTS) cable, twisting and transposition is applied to HTS tapes for a uniform current distribution and stable operation. Non-twisted and simple-stacking HTS cable designs are explored in NIFS for DC operation, as it is a mechanically robust cable and easy to manufacture.
High cryogenic stability of HTS suggest under a numerical exploration, that simple-stacking configuration may be stable. Experimental results for the STARS and L-RAISER conductors under trapezoidal current input, confirm stable operation on a coil configuration with simple-stacking, even with the presence of inductance difference between strands, up to 18 [kA] and 2000 [A/s].
As a follow-up from a straight HTS cable scenario, a numerical simulation was developed accounting the superconducting properties of HTS and the inductance difference between strands, to understand better how the current distributes in a simple-stacking configuration, assuming constant temperature.
Insights were obtained for the role of joint resistance, stabilizer resistance and mutual inductance in the current distribution and circulation currents formation. This may indicate how current variation between strands occur for large HTS magnets based on the simple-stacking approach, and if they remain within a safe margin from the critical current threshold.