Title :
Three-Dimensional Micrometer-Scale Modeling of Quenching in High-Aspect-Ratio
Coated Conductor Tapes—Part II: I
Author :
Chan, Wan Kan ; Schwartz, Justin
Author_Institution :
Dept. of Mater. Sci. & Eng., North Carolina State Univ., Raleigh, NC, USA
Abstract :
YBa2Cu3O7-δ (YBCO) coated conductors (CCs) show great promise for applications, but due to a very slow normal-zone propagation velocity (NZPV), quench detection and protection in YBCO magnets may be difficult. Present YBCO CCs have been developed with a primary focus on maximizing the critical current density for elevated-temperature low-field or low-temperature high-field applications. As the market for magnet applications progresses, it becomes important to consider design parameters such as the thicknesses and properties of all YBCO CC components, with the intent of considering quench-related behaviors as an integral part of the conductor and magnet design processes. Thus, it is important to know the impacts of conductor parameters on quench behavior. Considering that the YBCO layer itself is on the order of a micrometer in thickness, quench behavior must also be considered at this scale length. Here, the highly accurate experimentally validated micrometer-scale 3-D tape model reported in Part I is used to study how variations in CC geometry and material properties affect quench behavior, including the NZPV, hot-spot temperature, and minimum quench energy. The parametric variations focus on quantities that can be most readily modified by CC manufacturers. Based on simulation results, the relative sensitivities of the quench quantities to the parametric variations are calculated to identify which CC design parameters are most impactful on quench behavior. The implications of these results for quench detection and protection are discussed.
Keywords :
barium compounds; critical current density (superconductivity); high-temperature superconductors; quenching (thermal); superconducting magnets; superconducting tapes; yttrium compounds; 3D micrometer-scale modeling; YBCO coated conductor components; YBCO layer; YBCO magnets; YBa2Cu3O7-δ; coated conductor design parameters; coated conductor geometry; coated conductor manufacturers; conductor design process; conductor engineering; critical current density; elevated-temperature low-field application; geometric properties; high-aspect-ratio YBCO coated conductor tapes; hot-spot temperature; low-temperature high-field application; magnet applications; magnet design process; material properties; micrometer-scale 3D tape model; minimum quench energy; normal-zone propagation velocity; parametric variations; quench detection; quench protection; quench-related behaviors; quenching; scale length; Conductors; Critical current density; Sensitivity analysis; Thermal quenching; Yttrium barium copper oxide; Coatedconductor; YBCO; high aspect ratio thin film; mixed-dimensional model; quenchmodeling; sensitivity analysis;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2011.2169670