Analysis on Electrical and Thermal Characteristics of a No-Insulation HTS Coil Considering Heat Generation in Steady and Transient States

This paper presents the design process of an equivalent circuit simulation (ECS) method and its analysis results to evaluate the delayed response time and thermal stability behavior of no-insulation (NI) second-generation high-temperature superconducting (2G HTS) coils. The electrical and thermal characteristics of NI HTS coil were introduced by many researchers through the simulation method base on ECS model, but the feature of heat generation by superconducting and stabilizer layer was not considered in the previous studies. In this study, we analyze the electrical and thermal characteristics considering heat generation of NI HTS coil in both steady and transient states. First, an electrical ECS model was proposed to numerically analyze the characteristics of the NI 2G HTS coil in steady and transient states. A steady-state simulation was performed under rated operating-current shooting to estimate the magnetic-field response performance of the NI HTS coil. The transient-state simulation was performed under an over-current shooting to analyze the thermal quench behavior. In addition, the simulation results of the NI HTS coil were discussed and compared with the experimental ones to validate the simulation approach based on the proposed equivalent electric-circuit model.