Charging Characteristics of 2G HTS Coils With Insulation, Metal-Insulation, Non-Insulation, and Smart-Insulation Using Circuit Simulations

This study aimed to compare and analyze the output characteristics of second-generation high-temperature superconducting racetrack coils with insulation, metal-insulation (MI), non-insulation (NI), and smart-insulation (SI). First, the output characteristics of each coil were experimentally validated, and circuit equations were examined to analyze these characteristics. The output characteristics were found to be affected by the turn-to-turn resistance. Circuit analysis was used to identify the nature of dependence of output characteristics on turn-to-turn resistance in addition to internal behavior and other mechanisms. In particular, an equation relating the output characteristics of the SI coil with temperature change was derived, and each coil model was simulated using the circuit equation. Then, the simulation results were analyzed, the advantages and disadvantages of each insulation method were discussed, and the validity of the simulation was confirmed. The circuit simulation proposed in this study is expected to facilitate advanced predictions in smart insulation material candidate groups.