Affiliations: [a] State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power, University Beijing, China
Abstract: REBCO coated conductors (REBCO CCs), the second-generation high-temperature superconducting (2G HTS) tapes, are subjected to electromagnetic stress in an electromagnetic environment, and tremendous stress can damage tapes such that lose their superconductivity. This paper uses the numerical method to simulate the electromagnetic response and related mechanical properties of the quasi-isotropic strand (Q-IS) under the applied magnetic field and carrying current and their combination. The simulation is based on the Kim model in which the critical current density is related to the magnetic field. First, the stress distribution of the superconducting core inside the Q-IS under the applied magnetic field and if transport current is given. According to the different magnetic field amplitudes and current amplitudes, the influence of the copper sheath and the filling layer thickness on the maximum stress of the Q-IS is studied. Also calculated the current distribution, magnetic field penetration, and stress distribution of the Q-IS under the conditions of transporting direct current (DC) and applying a 2 Hz sinusoidal alternating current (AC) magnetic field. The performance of the Q-IS is entirely different in the rising and falling durations of the magnetic field. Stress concentration occurs at the four corners of the superconducting core. The left and right sides of the superconducting core with relatively large stress and deformation are easily damaged.
Keywords: Quasi-isotropic strand, Kim model, current distribution, magnetic flux pinning, electromagnetic stress
