Induced Current-Based Performance Measurement System for Wide and Stacked HTS Wires

Recently, high-temperature superconductor (HTS)-based devices have been applied to practical electric power systems. In order to increase the critical currents of HTS wires, wide and stacked HTS wires are being extensively researched. However, general systems for testing critical currents via voltage taps are not accurate for measuring the critical currents of wide and stacked HTS wires. This paper proposes an induced current-based performance measurement system for wide and stacked HTS wires. The system consists of wide and stacked HTS wires and induction coils made of 2G HTS wire. The electromagnetic performance of the HTS wires and induction coil is analyzed using a finite element method program. The basic structure of the performance measurement system is designed and fabricated based on the electromagnetic analysis results. In the experiment, the characteristics of the HTS wire are analyzed under charge and discharge conditions from the viewpoint of induced currents. The current of the stacked HTS wires is measured by a Rogowski coil. As a result, we can accurately identify the characteristics of the wide and stacked HTS wires, such as critical current and joint resistance.