Search Results (44)

Fusion energy represents humanity’s most promising solution for achieving limitless, carbon-free power. The superconducting Tokamak has emerged as the primary pathway to realize this goal. China’s systematic multi-phase strategy, progressing from the Experimental Advanced Superconducting Tokamak (EAST) to the International Thermonuclear Experimental Reactor (ITER) partnership, and now advancing the China Fusion Engineering Demonstration Reactor (CFEDR), has catalyzed transformative innovations in fusion magnet technology, including the development of high-current-density Cable-in-Conduit Conductors (CICC) using both low-temperature superconductors (LTSs) and high temperature superconductors (HTSs), radiation-resistant ultra-low-resistance joints enabling efficient power transfer, multi-sensor quench detection systems with millisecond-level response for magnet integrity preservation, and cryogenic thermal management via multi-stage heat interception zones. This accumulated expertise in superconducting magnet technologies will accelerate the commercialization of fusion energy. Full article

High-temperature superconducting (HTS) conductor on round core (CORC) cables possess the combined features of high current-carrying capacity, strong mechanical properties, and excellent isotropic flexibility. The current relative research on the electromagnetic properties of straight CORC cables has been exceedingly mature. In high-field magnets, CORC cables are typically bent into coils to meet the compactness requirement. Evaluating the bending characteristics of CORC cables, particularly their post-bending electromagnetic properties, holds great scientific significance. In this paper, CORC cables with different sizes of central formers were fabricated to explore the impacts of the bending process and strain on their transport AC loss characteristics. A mapping method was proposed to couple mechanical and electromagnetic models. Results show that the cable sample with a 4 mm outer diameter of the central former exhibits a superior bending characteristic. The bending process on the transport AC loss of CORC cable lies in the redistribution of the magnetic field, while strain mainly affects AC loss by leading to local critical current (Ic) degradation. CORC cables with small bending diameters require electromagnetic–mechanical-coupling simulation to predict their electromagnetic characteristics accurately. Conclusions drawn from this paper will provide invaluable guidance for the fabrication of bent CORC cables. Full article

High-temperature superconducting (HTS) DC power devices operate at cryogenic temperatures to achieve high power density for aviation applications. Ensuring reliable operation requires an optimized insulation system capable of withstanding cryogenic DC stress. In this study, finite element numerical simulations were conducted to investigate the transient behavior of electric fields in HTS cable insulation under DC stress at cryogenic temperatures. The results demonstrate that the transient field distribution is strongly temperature-dependent, leading to prolonged high-field exposure near ground terminations. Strategies to mitigate electric field enhancement are proposed to improve insulation reliability, supported by a comparative evaluation of various insulating materials. The simulation-based insights provide design guidance for developing resilient insulation systems for HTS and other cryogenic DC devices. Full article

High-temperature superconductor (HTS) magnet systems, especially those designed for fusion reactors, require effective and reliable monitoring to avoid damaging anomalies. In tokamaks, some of the magnetic coils are time-dependent, which causes strain and large inductive voltages within the magnet, rendering detection of incipient quench challenging. Ionizing radiation can also create material defects and lead to non-uniform degradation of conductors. The resulting decrease in critical current uniformity across the magnet, along with manufacturing defects, such as failure of structural materials or cooling systems, can all potentially initiate a quench. HTS magnets have a lower normal zone propagation velocity than low-temperature superconductors, and this causes normal zones to be localized, increasing the risk of permanent damage. Fiber optic sensors have several qualities that are essential in fusion systems. Unlike traditional voltage-based sensors, fiber optic cables are immune to the large electromagnetic fields present. This study presents and validates a fiber optic interrogation technique for monitoring magnetic confinement fusion and other high-temperature superconducting magnet systems. Coherent-phase optical time domain reflectometry (OTDR) allows for the high sampling rates (tens of kHz) necessary to quickly detect and mitigate quench events over the long distances required to monitor fusion magnet systems. This technique was demonstrated to successfully detect localized thermal transients at cryogenic temperatures as low as 6 K. These outcomes were also demonstrated using fibers embedded in HTS magnet coils at 77 K, verifying the potential for this interrogation technique’s use for failure detection in HTS coils. Full article

With the increase in urban cableization rate and cable length, the overvoltage problem caused by the capacitive effect becomes more and more serious. To limit overvoltage and achieve regional reactive power balance, shunt reactors are installed in substations. Based on a series of previous research, a type of superconducting toroidal air-core reactor is presented in this paper. The aim is to improve the power density of reactive power compensation and reduce magnetic leakage and noise pollution. In this paper, the structural optimized design of a 10 kV/1 MVar reactor is carried out based on COMSOL and MATLAB. In consideration of the usage of high-temperature superconducting tapes and AC loss of the reactor, combined with critical current, this paper uses corresponding finite element method (FEM) models and the optimal solution set is obtained via multi-objective genetic algorithm (MOGA). Finally, the solutions are analyzed economically and the set of solutions with the lowest cost is obtained, which provides a reference for the actual fabrication of a toroidal reactor in Shanghai, and can be used in the design of superconducting reactors at higher voltage levels. Full article

Modeling the electromagnetic (EM) behavior of CORC^® cables presents significant computational challenges due to the coexistence of thin superconducting tapes and thick structural formers. This creates a strongly multiscale problem, making traditional FEM-based approaches cumbersome, as they require extremely fine meshes to accurately resolve the different geometric scales. Integral Equation Methods (IEMs), on the other hand, are well-suited for magnetization loss analysis in multiscale superconducting structures, as they avoid modeling non-EM-active parts of the domain. This greatly reduces the effort involved in meshing the computational domain. In this work, we propose an IEM that couples surface and volumetric models to perform transient nonlinear analysis of CORC^®-like superconducting cables. Full article

Green hydrogen plays a vital role in facilitating the transition to sustainable energy systems, with stable and high-capacity offshore wind resources serving as an ideal candidate for large-scale green hydrogen production. However, as the capacity of offshore wind turbines continues to grow, the increasing size and weight of these systems pose significant challenges for installation and deployment. This study investigates the application of high-temperature superconducting (HTS) materials in the generator and the power conducting cables as a promising solution to these challenges. Compared to conventional wind turbines, HTS wind turbines result in significant reductions in weight and size while simultaneously enhancing power generation and transmission efficiency. This paper conducts a comprehensive review of mainstream electrolysis-based hydrogen production technologies and advanced hydrogen storage methods. The main contribution of this research is the development of an innovative conceptual framework for a superconducting offshore wind-to-hydrogen energy system, where a small amount of liquid hydrogen is used to provide a deep-cooling environment for the HTS wind turbine and the remaining liquid hydrogen is used for the synthesis of ammonia as a final product. Through functional analysis, this study demonstrates its potential for enabling large-scale offshore hydrogen production and storage. Additionally, this paper discusses key challenges associated with real-world implementation, including optimizing the stability of superconducting equipment and ensuring component coordination. The findings offer crucial insights for advancing the offshore green hydrogen sector, showing that HTS technology can significantly enhance the energy efficiency of offshore wind-to-hydrogen systems. This research provides strong technical support for achieving carbon neutrality and fostering sustainable development in the offshore renewable energy sector. Full article

For the large-scale fusion magnets of the International Thermonuclear Experimental Reactor (ITER) tokamak, wound with cable-in-conduit conductors, the application of sophisticated numerical models able to analyse the thermal–hydraulic behaviour during plasma scenarios is of paramount importance to guarantee an adequate stability margin during operating conditions. The SuperMagnet code has been developed by CryoSoft with the intent to simultaneously simulate the electrical, thermal and hydraulic phenomena occurring during the operation of superconducting coils. In this work, the SuperMagnet code is applied to analyse the thermal–hydraulic behaviour of the central solenoid of the ITER tokamak under the plasma scenario. The central solenoid (CS) is composed of six modules for a total amount of 240 pancakes. The software is able to tackle the complex structure of the CS and its cryogenic closed loop. In the present work, the circulation pump operation and the heat transfer to the helium bath are investigated. The results presented here show the temperature evolution of the magnet and of the supercritical helium during the plasma scenario, which allows the determination of the operation margin of the CS. Full article

Embedding stacked HTS tapes into twisted slots is one design approach for constructing fusion conductors. This paper adopts a Cable-in-Conduit Conductor (CICC) structure, utilizing commercially REBCO coated conductors. The cable framework is made of copper and features six helically twisted slots filled with 2G HTS tapes. Two 1 m long samples with twist pitches of 200 mm and 300 mm, respectively, were fabricated. In one slot, copper and superconducting tapes were alternated, while the remaining grooves were filled with copper tapes. The 90 µm thick copper-plated bare tapes provided by Shanghai Superconductor were used for testing. By measuring the critical current of tapes positioned at different locations within the grooves at 77 K, the characteristics of each tape in the stacked arrangement were individually characterized. The study obtained the current degradation patterns of tapes located at different positions within the grooves under various bending radii. This paper will present and discuss the preliminary results of the bending measurements conducted at 77 K under a self-field. Full article

In recent years, the scientific and industrial interest regarding alternative technologies for transmission cables has increased. These conductors should efficiently transmit significant amounts of power between grid nodes, which are expected to be particularly congested due to the projected global increase in electricity production. Superconducting cables are considered a promising solution in this context, offering the potential to transmit large amounts of energy with minimal losses and compact dimensions, thereby potentially benefiting the environment. To evaluate the feasibility of integrating superconducting cables into existing grids, techno-economic approaches should be adopted. Such techniques enable the conceptual design of a specific cable structure, allowing users to explore a wide range of operating parameters to derive optimal designs. This paper reports a comprehensive techno-economic analysis of High Voltage Alternating Current (HVAC) cables realized with High-Temperature Superconducting (HTS) tapes, with the aim to transmit extremely high-power level. The optimal coaxial design is selected using Optimization Tool for Superconducting Cable Research (OSCaR) by implementing a graded approach to the critical current of the HTS tapes used for the different phases. This optimization aims to achieve the most effective balance between the cost of the coated conductors and their electrical properties. The whole set of model equations, the user-defined parameters, and the applied constraints are detailed. The OSCaR tool is then applied to assess the impact on the optimized design of the cable system and the corresponding cost indexes of several crucial parameters, such as the maximum transmitted power, the voltage level, and the line length. Full article

The laying of power cables is a crucial aspect of developing and maintaining modern electrical infrastructure, which is vital for transmitting electricity reliably and efficiently. This review discusses the challenges and advancements in cable laying technologies, emphasizing the critical role of these techniques in meeting the increasing demands for power transmission in the backdrop of the global shift to renewable energy. Three main traditional cable laying methods are explored, including underground, overhead, and submarine, each suited to specific environmental and operational conditions. Then, the cable faults due to the impropriate laying process are discussed. Subsequently, the challenges and advancements encountered in cable laying processes are investigated, especially the difficulties of the cable laying of underground cable, submarine cable, and high-temperature superconductivity cable. This review also considers the impact of technological innovations on improving efficiency in cable laying processes, highlighting the advances driven by digitalization and automation. Full article

This study aimed to enhance the performance of Ag-stabilized high-temperature superconducting (HTS) tapes with a focus on reducing magnetization losses. Two approaches were employed: dividing the tapes into narrower widths and introducing striation at the level of the superconducting layer. The process of laser ablation proved to be an effective method for implementing these modifications. The quality of the cut edges and grooves was assessed using scanning electron microscopy. To evaluate the electrical properties, measurements were conducted on the critical current and magnetization loss in samples at different stages: in their initial state, after cutting, and after the striation process. Of the two modifications, the striation process more effectively reduced the AC losses in the HTS tapes, approximately by one order of magnitude. The retention of critical current remained high after cutting, but varied with the number of created filaments after the striation process. Subsequently, a short cable was wound from the cut and striated HTS tape. This cable demonstrated a remarkable sixfold reduction in AC losses compared to the initial HTS tape. Full article

Ensuring the energy transition in order to decrease CO₂ and volatile organic compounds emissions and improve the efficiency of energy processes requires the development of advanced materials and technologies for the electrical energy sector. The article reviews superconducting materials, functional nanomaterials used in the power industry mainly due to their magnetic, electrical, optical, and dielectric properties and the thin layers of amorphous carbon nitride, which properties make them an important material from the point of view of environmental protection, optoelectronic, photovoltaic and energy storage. The superconductivity-based technologies, material processing, and thermal and nonthermal plasma generation have been reviewed as technologies that can be a solution to chosen problems in the electrical energy sector and environment. The study explains directly both—the basics and application potential of low and high-temperature superconductors as well as peculiarities of the related manufacturing technologies for Roebel cables, 1G and 2G HTS tapes, and superconductor coil systems. Among the superconducting materials, particular attention was paid to the magnesium di-boride MgB₂ and its potential applications in the power industry. The benefits of the use of carbon films with amorphous structures in electronics, sensing technologies, solar cells, FETs, and memory devices were discussed. The article provides the information about most interesting, from the R&D point of view, groups of materials for PV applications. It summarises the advantages and disadvantages of their use regarding commercial requirements such as efficiency, lifetime, light absorption, impact on the environment, costs of production, and weather dependency. Silicon processing, inkjet printing, vacuum deposition, and evaporation technologies that allow obtaining improved and strengthened materials for solar cell manufacturing are also described. In the case of the widely developed plasma generation field, waste-to-hydrogen technology including both thermal and non-thermal plasma techniques has been discussed. The review aims to draw attention to the problems faced by the modern power industry and to encourage research in this area because many of these problems can only be solved within the framework of interdisciplinary and international cooperation. Full article

The Société Nationale des Chemins de fer Français (SNCF) is facing a significant challenge to meet the growth in rail traffic while maintaining continuous service, particularly in densely populated areas such as Paris. To tackle this challenge, the SNCF has implemented several electrification projects. These projects aim to reduce line losses and decrease voltage drops on the railway network. Amongst the possible technological choices, high temperature superconductor (HTS) cables have been evaluated, since they offer greater energy density at lower electrical losses than conventional cables. This feature is advantageous in order to transmit more electrical energy at a lesser footprint than conventional cable, therefore avoiding costly modifications of the existing infrastructures. In the present work, the electromagnetic response of two HTS cables topologies, unipolar and bipolar, was analyzed, and their impact on a direct current (DC) railway network under load was assessed. A commercial finite element (FE) software, COMSOL Multiphysics, was used to carry out a detailed FE model that accounts for the non-linearity of the electrical resistivity ρ (J, B, θ) of the superconducting cable. This FE model was coupled with a lumped-parameter circuit model of the railway network, which is particularly suited for transient simulations considering train motion. Based on a case study representing a portion of the Parisian railway network, it was found that the insertion of a superconducting cable can result in a reduction of electrical losses by 60% compared to conventional cable as well as an 8.6% reduction in the total electrical consumption of the traction network. Full article

To draw a complete vortex phase diagram for a CaKFe₄As₄ polycrystalline iron-based superconductor, different kinds of magnetic measurements have been performed focusing on the critical parameters of the sample. Firstly, magnetic moment versus field measurements m(H) were performed at low fields in order to evaluate the lower critical field H_c1. After that, by performing relaxation measurements m(t), a field crossover H_cross was detected in the framework of a strong pinning regime. The irreversibility field H_irr as a function of the temperature curve was then drawn by plotting the critical current densities J_c versus the field for temperatures near T_c. J_c(H) has demonstrated a second magnetization peak effect phenomenon, and the second peak field H_sp has been identified and plotted as a function of temperature, providing information about an elastic to plastic transition in the vortex lattice. Finally, the upper critical field H_c2 as a function of the temperature has been obtained. H_c1, H_cross, H_sp, H_irr, H_c2 have been fitted and used for drawing the complete vortex phase diagram of the sample. It can be helpful for the understanding of the applicative ranges in the field and temperature of the materials with not-optimized fabrication characteristics, as usually is found in superconducting wires and cables for power applications. Full article