Influence of Dynamic Resistance on Current Distribution of HTS DC Cable Conductor for Feeder Lines and Large Scale Magnet

HTS DC cable conductors are promising because of high current density and intrinsic zero resistance. Therefore, HTS cable conductor with large current carrying capacity are expected to have widespread application in feeder lines and large scale magnets. At present, the conventional design of HTS cable conductor, general several of 10 kA, are designed with goal of uniform current distribution by adjusting winding pitch same as AC HTS cable since the ripple current is unavoidable in DC transmission line and AC current in process of exciting and demagnetizing is also alternative. Thus, AC magnetic field component generated on tapes of HTS cable conductor is non-negligible. If the AC magnetic field component is higher than the penetration field of the HTS tapes, there is inevitable dynamic resistance among them. Dynamic resistance is seldom considered in previously conventional design of DC cable conductors. The dynamic resistance significantly affects the current distribution among HTS tapes except for generating extra loss and incurring instability. Based on the conventional design method of uniform current, this paper presents the DC current distribution among layers by considering dynamic resistance, which is particularly much more significant for large current capacity HTS DC cable conductors with ripple currents.