Transient Stability Characteristics of a 1-m Single-Layer YBCO Cable

Abstract

YBCO tapes are expected to be used in future high temperature superconductor (HTS) applications as they have better c characteristics at high temperatures and in high magnetic fields. For power applications such as transmission cables, YBCO tapes and a copper former are connected in parallel and they might be subjected to a short-circuit fault current that is 10 to 30 times the normal operating current. Therefore, the over-current behavior, including the hot-spot and the distribution of transport current between the copper-laminated YBCO tapes and the copper former, is very important to examine the stability and feasibility of the cable. This paper describes the experimental results for over-current pulses of a 1-m single-layer cable fabricated with five copper-laminated YBCO tapes and a copper former. Further, we performed numerical simulations by using a newly developed computer program based on the 3D finite element method.

Over-current characteristics of YBCO superconducting cable

“…We have also performed numerical simulations of these tests by using newly developed computer programs. By comparing the experimental results with the simulation results, the validity of the developed computer programs was confirmed [2,3]. In this study, we perform over-current tests on a 10-m-long YBCO model cable.…”

“…The model cable could endure faults without any degradation in the current. On the basis of our previous studies [1][2][3] and the present study, the developed computer program was used for designing the YBCO superconducting cable and determining its electromagnetic and thermal behaviors. In the future, we plan to develop a new model and a new numerical simulator for designing a three-phase YBCO superconducting cable.…”

“…In previous studies, we carried out experiments on single-YBCO coated conductors and YBCO coated conductors connected in parallel, to investigate their normal-zone initiation and propagation, degradation, and current redistribution characteristics [1,2]. In addition, we conducted over-current tests on a 1-m-long single-layer YBCO model cable in order to investigate the current redistribution and increase in temperature of the Cu former and YBCO coated conductors [3]. We have also performed numerical simulations of these tests by using newly developed computer programs.…”

Overcurrent Tests and Numerical Simulations on a 66-kV-Class RE123 High-Temperature Superconducting Model Cable

“…Numerical simulations to the tests were also performed using the developed computer program. As a result, the validity of the computer program was confirmed by comparing the experimental results with the simulation results [9], [10]. The conductor designs of overcurrent protection systems were proposed that could protect the 66-kV-class RE123 HTS power cable from the fault current without degradation and that would be sufficiently compact to be installed in the cable conduit [11], [12].…”

“…In addition, overcurrent tests were performed on 1-m-long and 20-m-long HTS model cables in order to measure the current redistribution and temperature rise under the fault condition [9], [10]. Numerical simulations to the tests were also performed using the developed computer program.…”