Analysis of mechanical and quench behavior in high-temperature superconductors for energy storage coils

Superconducting materials exhibit superior electromagnetic properties, such as zero electrical resistance and the Meissner effect. These characteristics endow superconducting materials with extensive application potential across contemporary sectors including energy, transportation, electric power, healthcare, telecommunications, and aerospace. However, superconducting materials typically operate within a sophisticated environment characterized by extremely low temperatures, intense magnetic fields, and significant current levels. Under the slight thermal, mechanical, electrical and magnetic disturbances, quenching is easy to occur, potentially endangering the stability and security of the system. For this reason, in order to reduce the damage to the superconducting system caused by quench, the multi-field coupling characteristics and thermoplastic response of superconducting composites and structures during quench are theoretically studied in this paper. Firstly, utilizing the geometric configuration of the high-temperature superconducting (HTS) energy storage coil, a finite element model of the multi-layer composite structure of the superconducting tape is established. Secondly, the quench behavior resulting from local thermal disturbances at various temperatures is investigated through the coupling of transient electromagnetic field equations and heat conduction equations. Studies indicate that the instantaneous evolution of strain is closely correlated with temperature changes during the quenching process. At positions laterally distant from the heat source, the strain exhibits an initial decreasing trend followed by an increase, characterized by a distinct minimum point on the strain curve. However, at locations proximal to the heat source, the strain demonstrates a characteristic of continuous growth. Besides, with the further development of quenching, the growth rate of tensile strain in the unquenched region is obviously accelerated. That is, the thermal expansion in the quenched region can be transmitted to the unquenched regions through the interlayer, resulting in mechanical deformation in these regions. This phenomenon can provide a new perspective and technical approach for quench detection of high temperature superconducting structures.