Resistivity of REBCO tapes in overcritical current regime: impact on superconducting fault current limiter modeling

Abstract

A detailed knowledge of the resistivity of high-temperature superconductors in the overcritical current regime is important to achieve reliable numerical simulations of applications such as superconducting fault current limiters. We have previously shown that the combination of fast pulsed current measurements and finite element analysis allows accounting for heating effects occurring during the current pulses. We demonstrated that it is possible to retrieve the correct current and temperature dependence of the resistivity data points of the superconductor material. In this contribution, we apply this method to characterize the resistivity vs. current and temperature of commercial REBCO tapes in the overcritical current regime, between 77 K and 90 K and in self-field conditions. The self-consistency of the overcritical resistivity model ρ OC (I, T) is verified by comparing DC fault measurements with the results of numerical simulations using this model as input. We then analyze by numerical simulation to what extent using the ρ OC (I, T) model instead of the widely used power-law model ρ PWL (I, T) affects the thermal and electrical performance of the tapes in the practical case of a superconducting fault current limiter. A remarkable difference is observed between the measured overcritical current resistivity model ρ OC (I, T) and the power-law resistivity model ρ PWL (I, T). In particular, the simulations using the power-law model show that the device quenches faster than with the overcritical resistivity model. This information can be used to optimize the architecture of the stabilizer in superconducting fault current limiters.

Optimization Method for Extracting Stabilizer Geometry and Properties of REBCO Tapes

“…The first step requires a good initial guess of the involved quantities (namely h Ag and ρ Ag (T )). This is done by combining the characteristics provided by the manufacturer on the data-sheet with direct measurements of R vs T (carried out with an experimental setup similar to that described in [9]). The injected current to measure R vs T is very small (100 mA), and we can assume that the acquired voltage signal is given by the silver layer only.…”

Experimental and Simulation Study of Resistive Helical HTS Fault Current Limiters: Quench and Recovery Characteristics

“…Previous studies have reported simulation methods for SFCL using Matlab/Simulink [23,24] and finite element method in COMSOL [18,21,25,26]. In this paper, a multilayer electrothermal coupled simulation model was built in MATLAB ® /Simulink to study the electrical and thermal behavior of the SFCL coil during quench [17,18,27,28]. Two stainless steel (SS) layers, silver layer, superconducting layer, and substrate NiW layer were considered in the model.…”

“…There are a lot of studies on the current limiting and recovery characteristics of coated superconductors and resistive SFCLs, by the means of experiment and numerical modelling [10][11][12][13][14][15][16][17][18][19][20].…”

“…On the numerical modelling, Roy et al proposed a combined component power law to study the resistivity of superconductor in over-critical current regime [17]. Riva et al did a comprehensive calculation study in the resistivity of REBCO tapes in overcritical regime, by comparing power-law model and overcritical resistivity model [18]. Liang et al proposed and validated a modified E-J power law to simulate the quench behavior of R-SFCL [19].…”

“…In this paper, a helical bifilar coil where inner and outer windings are connected in series was designed and manufactured. The fault limiting characteristics and recovery performance of the SFCL was studied experimentally and simulation using an electro-thermal model in MATLAB/SIMULINK [18,21]. The fault tests were conducted up to Ipros= 15Ic,coil = 3795 A, and simulated case study was carried out under a much higher ratio of Ipros/ Ic, which is beyond the testing capability of experimental rig.…”