Current distribution and voltage–current relation in multi-layered LTS and HTS power cable core: a review

To achieve the necessary current carrying capacity superconducting power cables core should be combined from several current-carrying layers. The key problem of multi-layered cable design is the achievement of uniform current distribution among the layers. This problem is directly connected with voltage–current characteristics of tapes from which a cable is made. The solution is different for LTS and HTS power cables. The influences of the layers winding geometry on current distribution and core voltage–current relation are considered in this paper. The history of the problem is reviewed for LTS wires and power cables and HTS power cables. It is shown that for power cables core it is possible to achieve uniform current distribution among layers in a cable with 2–10 layers, depend on core diameter. The influence of non-uniform current distribution on index ( n-factor) of voltage–current characteristics of a core is analyzed. It is also shown that the length of the test-sample has sufficient influence on current distribution, voltage–current characteristics and other measurable parameters of a cable model.