An effective design for induced current reducing of a single-phase multi-layer HTS coaxial cable with former

High temperature superconducting (HTS) cables require a former layer to bypass fault currents and support superconducting tape. The former layer of the HTS cable does not conduct current in steady-state operation due to the resistance difference with the conducting layer. However, in practice, an induced current flows through the former layer due to the mutual interaction with the conducting layer. Therefore, the current distribution in the cable should be uniform and the induced current in the former layer must be minimized. This paper deals with an effective design of a single-phase multi-layer HTS coaxial (SMHTSC) cable with former layer. The optimal combination of the pitch length and the winding direction in the conducting layer and the shield layer was selected for uniform current distribution of the SMHTSC cable and minimization of induced current in the former layer. The current distribution of the SMHTSC cable was analyzed based on the numerical calculation results obtained using the impedance matching method. The results and discussions of the current distribution on the SMHTSC cable with and without former layer were compared and presented. (paper)