Numerical study of the influence of the encapsulation layer on the DC over-current performance of HTS coated conductors

The application of resistive superconducting fault current limiters (R-SFCLs) in voltage source converter (VSC)-based DC systems has been proposed, and the encapsulated high temperature coated conductors (HTS-CCs) used for R-SFCLs is getting practical. Thus, this paper respectively develops a 1-D HTS-CC model and a 2-D HTS-CC model with different thicknesses to investigate the resistance characteristics and the quench recovery time. The results show that the resistance of encapsulated HTS-CCs goes through the flux flow state before reaching the normal. Then, the encapsulation can expand the limit of fault current, and a suitable thickness is likely to reduce the total resistance of the R-FCL. Finally, due to the existence of the heat transfer between the HTS-CC surface and the liquid nitrogen bath, a thinner tape might recover faster, and the recovery time tends to rise slowly as the tolerated current increases.