Experimental and Numerical Study of Quench Characteristics of Nonuniform REBCO-Coated Conductors

This study numerically and experimentally analyzed the quench propagation characteristics of nonuniform REBa2 Cu3O7-δ (REBCO, RE = rare earth) coated conductors (CCs) at the self-field and under a nearly adiabatic conditions. Four nonuniform REBCO CCs cases were studied: a copper-laminated sample with a point defect, a bare sample with a point defect, a copper-laminated sample with a regional defect, and a bare sample with a regional defect. The finite element method was used with the numerical computational models for these four nonuniform cases. The temperature and voltage profiles obtained from the numerical models were compared with experimental data. The quench parameters, including the peak temperatures in the defect region and normal zone propagation velocity, were obtained at various operation currents (from 36% I c to 112% I c). Of the four cases, the bare sample with the regional defect had the highest peak temperature at the same time and percentage of critical current ( I c). The results will be useful for the quench detection and protection design of REBCO CCs for use in applications.