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ISSN: 2772-8307
Copyright © 2026 Shanghai Jiaotong University. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
cited:15
A statistical model for the design of rotary HTS flux pumps based on deep-learning neuron network
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Article Number:Article 100017
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Abstract
Corresponding email:Hongye.Zhang@manchester.ac.uk; Markus.Mueller@ed.ac.uk
Rotory high temperature superconducting (HTS) flux pumps can consistently generate a DC voltage by rotating magnets over superconducting tapes, and thus energize the circuit if a closed loop is formed. The voltage output is a crucial factor to reflect the performance of such an HTS flux pump, which is determined by a set of design specifications, and some of them have been investigated extensively in the current literature. However, no work has been done yet to study the HTS dynamo output voltage by efficiently integrating all the design parameters together. In this paper, a well-trained deep-learning neuron network (DNN) with back-propagation algorithms has been put forward and validated. The proposed DNN is capable of quantifying the output voltage of an HTS dynamo instantly with an overall accuracy of approximately 98% with respect to the simulated values with all design parameters explicitly specified. The model possesses a powerful ability to characterize the output behavior of HTS dynamos by considering multiple design parameters, e.g., airgap, superconductor tape width, operating frequency, remanent flux density, rotor radius, and permanent magnet width, which have covered all the typical design considerations. The output characteristics of an HTS dynamo against each of the design parameters have been successfully demonstrated using this model. Compared to conventional time-consuming finite element method (FEM) based numerical models, the proposed DNN model has the advantages of automatic learning, fast computation, as well as strong programmability. Therefore the DNN model can greatly facilitate the design and optimization process for HTS dynamos. An executable application has been developed accordingly based on the DNN model, which is believed to provide a useful tool for learners and designers of HTS dynamos.
cited:64
A review of superconducting fault current limiters compared with other proven technologies
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Article Number:Article 100018
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Abstract
Corresponding email:mzamboti@id.uff.br
Several substations in operation were commissioned decades ago. These substations are overstressed, then their protection equipment cannot provide an effective safety condition to the system. In the worst cases, short-circuits can cause permanent damage to the system if the overcurrent is higher than the capacity of the installed equipment. There are some possible solutions for those cases: replace all the equipment in the overstressed substation, build a new one in parallel or install a fault current limiter (FCL) device. From an economic point of view, introducing FCLs in the power system is the best way to solve the described problem. The commercial solutions available are the pyrotechnic FCL, air coil reactor, neutral earthing resistor, and high impedance transformer. However, these devices are limited and present several drawbacks. Since the ’70s, there has been a search for reliable FCL devices that do not interfere in the regular operation of substations and could limit the fault currents to the protection system rated level. There were so many FCL technologies proposed in the last decades. These proposed new devices may use superconducting technologies, power electronics, or both. This paper reviews proven FCL technologies, focusing on full-scale devices demonstrated in field and lab tests. The goal is to introduce the main FCL technologies in development and discuss didactically their operation principle, the built prototypes, the commercial units, whether they exist, and the main drawbacks for each technology presented. A final analysis of the level of maturity for each FCL technology is discussed using the TRL (Technology readiness level) scale in order to find technologies with more potential for mass production. The three technologies closer to the full commercial application are: the Resistive Superconducting FCL, the Saturated Iron Core FCL, and the Series Reactor FCL.
cited:28
Development of a Roebel structure transposed cable with in-plane bending of REBCO tapes
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Article Number:Article 100019
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Abstract
Corresponding email:xuqj@ihep.ac.cn
A compact High Temperature Superconductor (HTS) cable that can carry large current is crucial for developing high field superconducting accelerator magnets. Herein, we are reporting a high current and low AC loss REBCO cable that adopts the Roebel structure, but it is implemented by in-plane bending stacked REBCO tapes directly to realize the transposition, instead of by punching REBCO tapes to the desired shape. The cable maximizes the utilization of the original REBCO tapes, so that the material cost is significantly reduced comparing with the present “Roebel” REBCO cable. Recently, a prototype cable has been successfully fabricated. The critical current of each REBCO tape after cabling shows no degradation, and the cable’s measured critical current is 1939.8 A at 77 K and self-field, which is very close to the predicted critical current by simulation. Calculations also show that the AC loss of the cable is lower compared with that of a simple REBCO stack with the same cross-section and current-carrying capacity. In this paper, we first introduce the fabrication process of the cable. What follows is the measurement of the in-plane bending performance of REBCO tapes. Then, we present the design and fabrication of the prototype cable together with current-carrying performance tests. Finally, the AC loss calculation and analysis of the cable are reported.
cited:10
Impact of Perlator on the cooling liquid flow and hottest point temperature of superconducting windings in HTS transformer
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Article Number:Article 100021
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Abstract
Corresponding email:mohammad.yazdani-asrami@glasgow.ac.uk
The generated heat by the superconducting windings and the other parts such as current leads in transformer increases the hottest point temperature (HPT) and causes the high temperature superconducting (HTS) windings to quench. Due to the properties of superconducting windings, reducing the HPT is of critical importance for the stable operation of the HTS transformer. The cooling system of HTS transformers, not only provides the cryogenic temperature for the proper operation of the superconductors but also is responsible for dissipating the generated heat by the windings. In this paper, the effect of the angle of inlet pipes in cooling system was investigated. This was a simple and effective solution which increases the heat transfer in liquid nitrogen. It was shown that inlet angle has a significant effect on the flow turbulence and the windings temperature. The Perlator is used as a lattice sheet which is installed inside the inlet valve and increases the turbulence of inlet flow of liquid nitrogen to increase heat transfer and reduce HPT. The thermal analysis is obtained by finite element method using ANSYS Fluent software. The influence of changing the inlet pipe angle and different structure of Perlator on heat transfer was investigated.
cited:21
Optimizing coil configurations for AC loss reduction in REBCO HTS fast-ramping magnets at cryogenic temperatures
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Article Number:Article 100024
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Abstract
Corresponding email:Zhenan.Jiang@vuw.ac.nz; Honghai.Song@stonybrook.edu
AC loss is one of the critical issues for designing REBCO fast-ramping magnets operating at cryogenic temperatures. There are many ways to reduce AC loss for coil windings. However, it is not clear which method is the most effective way to minimize AC loss in the coil windings for a given Ampere-turns. In this work, we numerically studied coil configurations of several small superconducting magnets constructed from 12 mm SuperPower REBCO coated conductors, for fast-ramping application with the same Ampere-turns to identify the lowest AC loss among them. The HTS magnets have a total turn number of 50 and inner diameter of 30 cm, carrying AC current operating in the temperature range of 20–40 K at 25 Hz. We incorporated several existing loss reduction strategies including spacing between the turns for single pancake coils, grading Ic values for the solenoid configuration, and applying flux diverters to shape the magnetic field around the coil windings. The simulation was implemented using a homogenized H-formulation. Across all studied loss reduction methods, the use of flux diverters has the largest impact in AC loss reduction. The AC loss values in the solenoid winding comprising a stack of five single pancake coils with 0.1 mm turn-to-turn gap with the flux diverters agree well with those in the single pancake coil for 2 mm turn-to-turn gap with the flux diverters. Solenoid type coil configurations with flux diverters generate much smaller AC loss than the single pancake type with flux diverters when they generate the same center magnetic field.
cited:32
Review on thermal-related measurement methods for superconducting devices and prospect for high-speed maglev transportation application
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Article Number:Article 100020
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Abstract
Corresponding email:jzheng@swjtu.edu.cn
High-temperature superconducting (HTS) bulks can not only be self-stable when levitated above a permanent magnet (PM) but also can be used as quasi PM with higher magnetic energy product due to their magnetic flux pinning characteristics. Therefore, HTS bulks have wide application potentials in maglev trains, maglev bearings, flywheel energy storage, drug delivery, and high field magnets. In the external magnetic field of common application scenarios, HTS bulks have no external input current, so it is difficult to achieve the overall quench. However, local quenching in the bulk is still possible in the harsh fluctuating external field environment. Although it is difficult to reach the total quench, its critical parameters like Jc will inevitably deteriorate, which may collapse the application system. Therefore, in contrast to superconducting wires and tapes that are more concerned with quench detection, HTS bulks with a 3D volume effect are more focused on internal sensitive temperature locations, the impacts of volume and scale, and the coupling influence on application parameters such as magnetism and force. Therefore, for efficient thermal-related measurement of HTS bulk applications, this paper investigates and discusses 12 commonly-used temperature measurement or quench detection methods in all superconducting application fields. These methods primarily refer to the current quench detection technologies used in HTS tapes and wires. From the standpoint of practical temperature measurement requirements of HTS bulks and technological limitations of maglev application scenarios, working characteristics and service conditions of the 12 methods, and 4 temperature detection methods are selected through a comprehensive understanding and comparison of basic principles. They are expected to be used in real-time monitoring and early warning schemes for onboard superconducting levitation devices of HTS maglev transportation or other applications in the future.
Review