Impact of a REBCO coated conductor stabilization layer on the fault current limiting functionality

Abstract

Reliability is one of the crucial requirements of conductors used in resistive superconducting fault current limiters. Possible critical current degradation of a REBCO coated conductor during the limiter operation restrains broader application of devices based on these conductors. In this article the impact of an electrical stabilization layer on the conductor protection against overheating as well as its effect on electrical current evolution during the limitation period are investigated. For the experimental part of the study, a commercial copper stabilized REBCO coated conductor and a modified conductor without copper stabilization are compared. Extensive experimental work complemented by electro-thermal numerical modeling paved the way for studying the electrical and thermal effects separately. The numerical model assuming adiabatic conditions is sufficient to reproduce experimental results and predict the peak temperature for conductors with various stabilization layers in realistic conditions. Reduction of the conductor critical current caused by multiple current limitation pulses was studied using pulses with various durations. It was observed that the degradation due to temperature rise is gradual with the rate depending solely on the peak temperature. It is this quantity through which other parameters like the pulse duration, the thickness of stabilization and the peak current cause the tape damaging.

Composite Heat Sink Material for Superconducting Tape in Fault Current Limiter Applications

“…Conventional materials used to increase the heat capacity of the tape are brass, stainless steel or Hastelloy in compact [13][14][15] or porous form [16]. Drawback of these materials is their electrical conductivity, which reduces electrical resistivity of the tape and causes that more heat is generated at the same level of electric field [17]. Aluminium nitride ceramics is an electrical insulator with good thermal conductivity [18], but is difficult to prepare in form of a sufficiently thick layer.…”

Recovery performance of partially-joined porous-stabilized REBCO tape for resistive type superconducting fault current limiters

“…The recovery time of Model-In1-P was calculated by Sample-In1-P-2. According to the earlier study [23], the recovery time of the stabilizerfree REBCO tape was the shortest because it has the highest current-limiting performance and the joule heating in the tape was smaller than that of the stabilized REBCO tapes. However, in this study, the recovery time of Model-In1-P and Model-In5-P were shorter than that of Model-Bare by 69%, and the quick recovery within 1 s was realized.…”

Electro-thermal modelling by novel variational methods: racetrack coil in short-circuit

“…For 5 V/m, the coil experiences fast electro-thermal quench, bringing the superconductor above the critical temperature of 92 K and reaching up to 450 K (figure 6). Although the temperature is high, most REBCO tapes do not get damaged under these conditions [29,30]. The fault current (or peak of current) reaches up to 198 A (1584 A×turns), which is 1.32 times the I c at 77 K. Shortly afterwards, the superconductor overcomes the critical temperature and the current sharply decreases to below 100 A×turns.…”