Safety analysis of 55 kA high-temperature superconducting current lead under cooling loss condition

This paper presents a safety analysis of high-temperature superconducting (HTS) current leads under cooling failure conditions using fundamental heat transfer principles. The HTS section of the lead employs Bi-2223/Ag-Au superconducting material as the current-carrying medium. By utilizing ANSYS software’s steady-state and transient heat transfer capabilities, an axisymmetric design was developed at a 1/90 scale of a 55-kA current lead. This scaled model indirectly reflects performance parameters while reducing experimental costs and technical complexity. Analysis results indicate a Loss of Flow Accident (LOFA) time of 560 s and an overheating time of 45 s under steady-state current conditions. Temperature-displacement relationships under different deformation degrees were also established. When temperature reaches approximately 500 K, the hotspot locates at 70 % of the lead length with a 3.8 mm deformation. Experimental test data validated the feasibility of this method, providing a reference for subsequent testing.