Electrical and Magnetic Characterization of BSCCO and YBCO HTS Tapes for Fault Current Limiter Application

Abstract

Several high temperature superconductor (HTS) tapes have been developed since the late eighties. Due to the new techniques applied for their production, HTS tapes are becoming feasible and practical for many applications. In this work, we present the test results of five commercial HTS tapes from the BSCCO and YBCO families (short samples of 200 mm). We have measured and analyzed their intrinsic and extrinsic properties and compared their behaviors for fault current limiter (FCL) applications. Electrical measurements were performed to determine the critical current and the value through the V-I relationship under DC and AC magnetic fields. The resistance per unit length was determined as a function of temperature. The magnetic characteristics were analyzed through susceptibility curves as a function of temperature. As transport current generates a magnetic field surrounding the HTS material, the magnetic measurements indicate the magnetic field supported by the tapes under a peak current 1.5 times higher than the critical current, . By pulsed current tests the recovery time and the energy/volume during a current fault were also analyzed. These results are in agreement with the data found in the literature giving the most appropriate performance conductor for a FCL device (I peak = 4 kA) to be used in a 220 V-60 Hz grid.

AC losses in thin coated conductors under non-sinusoidal conditions

“…To estimate this parameter, we consider a coated conductor with the width 2a = 1 cm and the hastelloy-C substrate thickness of 0.1 mm. The substrate resistivity is 1.24 × 10 −6 m, the resistivity of silver and copper layers is about the same and is equal to 2 × 10 −9 m at 77 K. Hence, for a coated conductor without protective silver and stabilizer layers [2,3], the parameter α is about (10 6 s −1 )/f ; for a conductor with the 2 µm thick silver layer [21], α ≈ (8 × 10 4 s −1 )/f ; for a well stabilized coated conductor with the copper stabilizer thickness of 100 µm [22], the parameter α is evaluated as (1.6 × 10 3 s −1 )/f . Hence, the losses in a superconductor dominate for the first two conductor types up to high frequencies of the order of 1 MHz.…”

Critical current of a layered high-temperature superconductor with artificial pinning centers: the Monte Carlo simulation

“…Superconducting nanowires have recently been used as detectors capable of registering single photons [1,2] and as memory elements [3]. Micro-bridges can be used as constituents of current limiters [4][5][6], and high-temperature superconductors (HTSs) such as yttrium and bismuth-based cuprates, the advantage of which is the ability to function at nitrogen temperatures, have recently been proposed for designing such devices. Both the shape of the current-voltage characteristics (EJ curves) and the magnitude of critical current j c are essential properties for various applications of HTSs, especially current limiters.…”

“…In [4], the EJ curves and the parameter characterizing their curvature (n-value) were measured for a macroscopic superconducting bridge. In [7], the bridge size in the direction perpendicular to the flow of current (i. e., in the direction along which the Abrikosov vortices enter the superconductor) ranged from tens to hundreds of nanometers.…”

Design Aspects and Test of an Inductive Fault Current Limiter

“…On the other hand, inductive SFCLs require an iron core which make them relatively heavy but do not need current leads, require lesser amounts of superconductor and are robust against hotspot formation. A field test has carried out by ABB Company many years ago using HTS bulk cylinders [10], and only recently, due to the emergence of HTS tapes [11], [12], [13] and [14], several projects have been performed, either using first generation [15] or second generation tapes [16].…”