A high-current and low-loss high-temperature superconducting cable for nuclear fusion applications
type: CreativeWork
description: The primary challenge in applying high-temperature superconducting (HTS) coated conductors (CCs) to AC energy applications, including motors, power transmission, and fusion magnets, is their relatively high AC loss. In this dissertation, a novel high-current and low-loss HTS cable, Patterned superconductors for AC loss minimization and current maximization (PSALM), is proposed and investigated to tackle the AC loss problem. Compared with the existing HTS cables, PSALMs are more compact, more capable of carrying large currents with minimized losses, and easier to manufacture. A 3D finite element method (FEM) model of the PSALM based on the T-A formulation is built to optimize the structure and verify the performance. Samples of PSALMs with a single superconducting layer are manufactured, tested, modeled, and analyzed. In the experiments, the critical current degradation and the transport AC losses are measured. In the simulation, the transport AC losses are calculated and compared with the experimental data, and the current distribution is analyzed in detail. The results show that compared with normal REBCO CCs, PSALMs with optimum patterns can reduce AC transport losses by 60\% through field-canceling and can reduce magnetization losses by the factor of the filament number through patterning. This model is then used to simulate long PSALMs which could be used in practice and calculate the transport AC losses. The losses are found over 30\% lower than that of the normal HTS REBCO tapes, which verifies the loss-reduction performance of the PSALMs. To explore the underlying physics of the PSALM, we then focus on the field-canceling effect of the PSALM introduced by the specially designed patterns on the buffer layers and superconducting layers. From the results obtained by the 2D and 3D models using the T-A formulation, we find this effect can make the current distributed more uniformly and can significantly reduce AC losses. The reasons and the basic principles behind…
abstract: The primary challenge in applying high-temperature superconducting (HTS) coated conductors (CCs) to AC energy applications, including motors, power transmission, and fusion magnets, is their relatively high AC loss. In this dissertation, a novel high-current and low-loss HTS cable, Patterned superconductors for AC loss minimization and current maximization (PSALM), is proposed and investigated to tackle the AC loss problem. Compared with the existing HTS cables, PSALMs are more compact, more capable of carrying large currents with minimized losses, and easier to manufacture. A 3D finite element method (FEM) model of the PSALM based on the T-A formulation is built to optimize the structure and verify the performance. Samples of PSALMs with a single superconducting layer are manufactured, tested, modeled, and analyzed. In the experiments, the critical current degradation and the transport AC losses are measured. In the simulation, the transport AC losses are calculated and compared with the experimental data, and the current distribution is analyzed in detail. The results show that compared with normal REBCO CCs, PSALMs with optimum patterns can reduce AC transport losses by 60\% through field-canceling and can reduce magnetization losses by the factor of the filament number through patterning. This model is then used to simulate long PSALMs which could be used in practice and calculate the transport AC losses. The losses are found over 30\% lower than that of the normal HTS REBCO tapes, which verifies the loss-reduction performance of the PSALMs. To explore the underlying physics of the PSALM, we then focus on the field-canceling effect of the PSALM introduced by the specially designed patterns on the buffer layers and superconducting layers. From the results obtained by the 2D and 3D models using the T-A formulation, we find this effect can make the current distributed more uniformly and can significantly reduce AC losses. The reasons and the basic principles behind…
author: Hao, Luning
language: eng
keywords: ac losses, fusion magnet, superconducting cable
license: https://www.repository.cam.ac.uk/bitstreams/1c280234-96ab-4215-9f77-4cac022f7325/download
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2024-04-08
date modified: 2026-07-22T22:23:56Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.110459