Self-field quench behaviour of YBa₂Cu₃O_7−δcoated conductors with different stabilizers

Abstract

Self-field quench behaviours of YBa 2 Cu 3 O 7−δ coated conductors with different stabilizers are studied. Samples include one with Cu on both sides (Cu-Cu), one with stainless steel on both sides (SS-SS), and one with Cu on one side and stainless steel on the other (Cu-SS). The measurements of the minimum quench energy (MQE) and normal zone propagation velocity (NZPV) are taken at various temperatures (30-75 K), and transport currents (30% I c to 90% I c ) at a typical pressure of 10 −5 Pa. Of the three samples, the Cu-Cu sample has the highest MQE while the SS-SS one has the lowest MQE at the same temperature and percentage of I c ; the NZPV in the SS-SS sample is found to be the highest while those of the Cu-Cu and Cu-SS samples are similar. The normal zone voltage and the hot-spot temperature are also compared. Both the classic adiabatic quench propagation model and the interface resistance model are used to explain the NZPV and MQE differences between the samples. The implications for conductor design and quench detection and protection are discussed.pared. The experimental approach, including sample description, measurement setup, protocol and data preparation, is presented first. The results of minimum quench energy (MQE) and normal zone propagation velocity (NZPV) of each sample follow. The ratio of the normal zone voltage and the peak temperature, a key parameter for detection and protection, is compared. Implications for conductor design and quench detection and protection are discussed.

Modeling and Experiment of the Current Limiting Performance of a Resistive Superconducting Fault Current Limiter in the Experimental System

“…The resistance of metal layers of a superconducting tape is regarded as the resistance of the six metal layers connected in parallel, which can be calculated with (14) and (15). As shown in (15), the resistivity of each metal layer is defined as functions of its average temperature.…”

“…As shown in (15), the resistivity of each metal layer is defined as functions of its average temperature.…”

Changes in the Thermal Stability of 2G HTS Wires by Local Modification of the Stabilization Layer

“…The same ablation process as performed in sample S1, with two areas of 4x2 mm 2 , was performed in a second sample with I c (77K)=97 A (Fig. 5(a)).…”

“…Some studies have analyzed the influence of different stabilizers [2] or the effect of the stabilizer thickness [3] on quench development and propagation. In a great number of experimental works, usually a normal zone region is initiated using a heater fixed on the sample surface.…”

Quench nucleation obtained by local reduction ofIcin coated conductors

“…There are several ways to act on the NZPV, e.g. acting on substrate thermal properties [5; 6], stabilizer architecture [7], interfacial resistance [8] or trough shunts configurations [9; 10]. In the present work, we investigate the influence of field-induceddefects and of the coolant temperature on the normal zone propagation.…”