Multi-Physics Characteristic Simulations of a Current-Limiting CORC Conductor for a 35 kV/1.5 kA Superconducting Fault Current Limiter (SFCL)

The rapid urbanization has led to a surge in short-circuit currents within the electrical grid, occasionally surpassing the interrupting capacity of circuit breakers. This challenge underscores the critical need to limit fault currents, representing a significant technical and economic issue for power grid management. Superconducting fault current limiter (SFCL) has the advantages of fast current limiting response, self-triggering, low loss and fast recovery, which is an effective solution to the short-circuit current problem. However, the existing SFCLs used in power grids have the problem of costing large amount of superconducting materials, which cannot meet the cost requirements of current limiting in medium and low voltage level lines. The SFCL with current-limiting CORC conductor has higher current-carrying capacity and lower production cost, which is expected to further enhance the reliability and economy of current limiting. Aiming at the current-limiting CORC conductor applied for a 35 kV/1.5 kA SFCL, an FEM model with electric, magnetic, fluid and thermal fields is established in COMSOL Multiphysics so as to explore the multi-field coupling mechanism under steady state and fault condition. Simulation results obtain the critical current, AC loss and magnetic field of the CORC conductor in steady state. Furthermore, The quench operation of the CORC conductor is performed by applying a fault RMS current of 17.5 kA and 1750 A to acquire its electromagnetic and thermal-fluid operation stability. This study explores the application prospect of CORC cable in SFCL and impels the practical application of SFCL.