Successful DC current limitation above 100 Vm⁻¹ for 50 ms using HTS tapes with critical currents exceeding 750 A/cm-width

Abstract

High-voltage direct current transmission systems are expected to allow the transmission of huge volumes of electricity over long distances. The use of superconducting fault current limiters (SFCLs) based on second-generation (2G) high-temperature superconductor (HTS) coated conductors (CCs) is a promising solution to mitigate fault currents in DC transmission systems. To fabricate a SFCL whose size remains acceptable, which means minimizing the length of the HTS tape used, the tape must sustain a high electric field during the whole fault duration. In this paper, high performance commercial 2G HTS CCs from THEVA (more than 750 A/cm-width at 77 K in self-field), on which a 500 µm thick Hastelloy shunt was soldered, were tested by submitting them to faults of different amplitudes and durations. Measurements revealed that these HTS tapes could sustain any type of fault up to 100 V m−1, lasting up to 50 ms. Three-dimensions finite element simulations were able to reproduce accurately the experiments by using the appropriate temperature dependence of the critical current density and power law index, and by accounting for the variations in the local critical current along the length of the HTS tapes.

Normal zone propagation in various REBCO tape architectures

“…The model used to perform the simulations is a modified version of the 3D model described in [6]. It has been implemented in the COMSOL Multiphysics 5.5 software package and uses two modules, namely the Electric Currents and Heat Transfer in Solids modules.…”

“…Increasing the electric field allows us to limit the length of the REBCO tape required, thus reducing the footprint and cost of the SFCL [5]. In particular, it was shown that soldering a 500 µm thick Hastelloy shunt on a REBCO tape (I c > 800 A cm −1 width at 77 K, self-field) allowed the tape to sustain an electric field over 100 V m −1 for 50 ms [6].…”

A sulfurization method for creating the buffer-layers current flow diverter architecture in REBa2Cu3O7 coated conductors

“…The current limitation tests shown here were taken during the European H2020-FASTGRID project which goal was to develop the best 2G HTS CC architecture for a superconducting fault current limiter (FCL) operating in a DC electrical network [5]. Large tape samples (⩾12 cm) were tested in DC fault current conditions using a setup similar to the one described in [44]. A voltage source was connected to both ends of samples with copper blocks held by bolts and screws.…”

Defining inkjet printing conditions of superconducting cuprate films through machine learning

“…Specific architectures have been designed, known as coated conductors (CC). 5 Although several companies are able to market CC, [6][7][8][9][10][11][12] low-cost and robust fabrication methods that guarantee sufficiently small cost/performance ratios are essential and only few are available. Chemical solution deposition (CSD) methods have demonstrated low cost and fine capabilities in the fabrication of REBCO superconducting films.…”