AC Loss and Thermal Stability of HTS Model Coils for a 600 kJ SMES

A 600 kJ superconducting magnetic energy storage system (SMES) project with high temperature superconductor (HTS) started as a national project in Korea. The HTS model coils were designed and fabricated for a preliminary test prior to the creation of a full scale prototype. Single reinforced BSCCO-2223 wires were used for the model coils and the operating temperature was decided to be 20 K. Even though an SMES is not an AC-powered device, time-varying currents during the charging and discharging periods lead to the generation of time-variation magnetic fields applied to the model coils and the generation of AC loss. In this paper, AC loss and the temperature distribution of model coils are analyzed and discussed.