Since HTS (High Temperature Superconductor) conductors becamecommercially available, many institutes and companies are trying to developsuperconducting power cables with more current capacity and less AC loss.Typically, the superconducting cable consists of a conductor layers, insulationlayers, shield layers and a cryostat filled with coolant such as liquid nitrogen.By arrangement of these parts a superconducting cable can be classified by twotypes; cold-dielectric and warm-dielectric. In the cold-dielectric design, eachphase core consists of conductor layers, an insulation layer and a shield layer,and the three phase cores are in a common cryostat. The shield layer is usuallymade of superconductor tapes. On the contrary, in the warm-dielectric design abig shield layer, which is out of the cryostat, covers all the three phase cores,and a shield for each phase core does not exist. A shield layer in this geometryis made of normal conductor. The current distribution among the conductorlayers is determined mainly by winding pitches and directions of the layers,because the inductance of the layer is controlled by the winding pitch anddirection. In the design of a superconducting cable, it is necessary to find anoptimal combination of pitch and direction which has an even currentdistribution. However, the optimal combinations for the cold-dielectric andwarm-dielectric geometries are different. Using developed software, westudied the effect of the shield layer position on current sharing characteristicsof a cable with two conductor layers. A brief description of the software,calculation results, discussions and recommendation for development arepresented in this paper.
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