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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:42
Numerical modelling of high-temperature superconducting dynamos: A review
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Article Number:Article 100033
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Abstract
Corresponding email:mark.ainslie@kcl.ac.uk
The high-temperature superconducting (HTS) dynamo enables injection of large DC currents into a superconducting coil, without the need for thermally-inefficient current leads. Because of this important advantage, there is significant interest in using such technology to energise superconducting coils in superconducting rotating machines and NMR/MRI magnets. Despite the extensive experimental work carried out over the past decade, there was – until very recently – considerable confusion and debate regarding the physical origin of the HTS dynamo’s DC output voltage. Numerical modelling has played a key role in elucidating the underlying physics of such devices and several different numerical models have now been developed as useful and cost-effective tools to not only explain and further examine experimental results, but also optimise and improve dynamo designs. This review summarises all of the developments in this important area over recent years, including modelling the open-circuit voltage behaviour in 2D and 3D, the definition of a new benchmark problem for the HTS modelling community, investigating key dynamo parameters, modelling dynamic coil charging behaviour and calculating losses. A view towards the future is provided, including the outstanding challenges and the developments required to address these.
cited:24
Critical current parameterization of high temperature Superconducting Tapes: A novel approach based on fuzzy logic
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Article Number:Article 100036
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Corresponding email:mohammad.yazdani-asrami@glasgow.ac.uk
In this study a novel method was presented to parameterize the critical current of Yttrium Barium Copper Oxide (YBCO) tapes based on their width, thickness, magnetothermal operational conditions, and the applied strain. For this purpose, a fuzzy-logic-based model was developed that take tapes structures and their operational conditions as inputs to calculate their critical current, as output. The results of critical current parameterization by fuzzy-logic-based model showed that the relative error of the proposed model is less than 3% comparing to experimentally acquired data. Then, the results of presented model was compared to results of semi-analytical fitting-based models and fully-analytical fitting based models. The comparisons showed the better performance in terms of accuracy and error of fuzzy logic model over fitting-based methods. At last, the results were also compared with the Artificial Neural Network (ANN)-based parameterization model and Adaptive Nero-Fuzzy Interference System (ANFIS)-based parameterization model. The proposed method had 6% to 8% higher accuracy and about 47% to 54% lower root mean squared error.
cited:21
Analytical analysis of hollow CORC cable under thermo-mechanical loads
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Article Number:Article 100037
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Corresponding email:tangyj@mail.hust.edu.cn
According to engineering experience, the axial shrinkage caused by the refrigerant seriously endangers the performance of long-distance conductor on round core (CORC) cables. Since outage maintenance of high-temperature superconducting (HTS) cables is inevitable, providing appropriate compensation for cyclic temperature is one of the key technologies in the actual application of power cables. Therefore, this paper presents an analytical solution for hollow CORC cables under thermo-mechanical loads. First, regarded as an axisymmetric composite structure, the radial temperature distribution of CORC cable under Dirichlet boundary or mixed boundary conditions was calculated. Then, assuming cable ends were axially fixed, a recursive method without variables is used to evaluate its displacement, strains, and stresses. Then, an algebraic method with axial strain as a variable is developed to analyze the mechanical behavior of the CORC cable more directly. Finally, concluded from the above derivation, a matrix equation is constructed based on continuity equations and boundary conditions, which applies to isotropic and orthotropic materials with orientations. Calculation results show that the analytical solution agrees with finite element method (FEM) results. Compared to the trial results of a 360 m CORC cable, the calculation error of axial shrinkage is within 1.63 cm, and the relative error is within 6.1%. In addition, the recursive method is the fastest to calculate axial strain, while the matrix method has a significant efficiency advantage in calculating the stresses and strains of each layer.
cited:7
Phase evolution mechanism study and fabrication of PbMo6S8 superconducting materials with two-step sintering process
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Article Number:Article 100038
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Abstract
Corresponding email:snzhang@c-nin.com
PbMo6S8 superconducting materials are considered to have great potential for practical applications at low temperatures and high fields due to their high upper critical field, low anisotropy, and low preparation cost. In this work, PbMo6S8 bulks were prepared through a solid-state sintering process using PbS, Mo, and MoS2 as raw materials. The phase evolution mechanism during the sintering of PbMo6S8 was studied in detail. It was found that during sintering at 750 °C for 24 h, both the S and Pb atoms diffuse into the Mo and MoS2 particles, leading to the formation of the PbMo6S8 phase. After sintering at 950 °C for 72 h, a high superconducting phase content was obtained in the bulk; however, numerous pores remained. Therefore, in order to obtain a higher density for the bulk, a two-step sintering process was developed. Based on this technique, PbMo6S8 bulks with a higher bulk density and a higher superconducting phase content were obtained. This study provides an effective method for the fabrication of high-quality precursor powders, which can be the foundation for the future fabrication of PbMo6S8 superconducting long wires or tapes for practical applications.
cited:30
Electromagnetic analysis and AC losses of triaxial cables with multiple 2G-HTS layers per phase
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Article Number:Article 100039
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Corresponding email:mlc42@leicester.ac.uk
For an accurate estimation of the AC losses of superconducting triaxial cables, in this paper we present a two-dimensional model capable to provide a global assessment of multi-layer triaxial cables, validated against the reported AC-losses measurements on single-phase cables provided by the Russian Scientific and Research Institute of the Cable Industry (VNIIKP). Four models are presented, the first being a single-phase cable of 50 tapes and the others being three triaxial cables made of up to 135 coated conductors distributed in up to 9 layers. A systematic study is devised, where the number of layers per phase increases from 1 to 3, with at least 14 tapes distributed across each layer of the first (innermost) phase, 15 in the secondary (middle) phase, and 16 in the third (outermost) phase, respectively. Remarkably, our results reveal that the simple strategy of considering an unbalanced distribution for the amplitudes of the applied current, can generally balance the magnetic field between the three phases even for the bilayer and trilayer cables, resulting in negligible magnetic leaks in all situations. Besides, our high-resolution simulations allow to see for the first time how the transport and magnetization currents distribute across the thickness of all the superconducting tapes, from which we have found that the AC-losses of the 2nd phase is generally higher than at the other phases at low to moderate transport currents, , being the critical current of the corresponding tapes. Nevertheless, depending on whether the of the SC tapes at the 3rd phase layers is lower than the one at the 2nd phase, the layers at the third phase can exhibit a considerable increment on the AC losses. This is result of the considered magneto angular anisotropy of the superconducting tapes, which lead to intriguing electromagnetic features that suggest a practical threshold for the applied transport current, being it . Likewise, the relative change in the AC-losses per adding layers, per phase, and as a function of the entire range of applied transport current is disclosed.
cited:4
The impact of magnetic field periodicity on the hysteresis loss in superconducting magnetic bearings
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Article Number:Article 100040
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Abstract
Corresponding email:mohammad.siamaki@vuw.ac.nz
Since the discovery of high-temperature superconductors (HTS), superconducting magnetic bearings (SMB) have attracted much attention for practical applications such as flywheel energy storage systems, electrical machines, gyroscopes, etc., because of their ability to provide passive stable levitation under high-load conditions. Despite providing contactless linear and rotational motion, SMBs gradually decelerate by AC losses mainly generated by magnetic field inhomogeneity. The main component of AC losses at low rotational speeds is hysteresis loss, which is said to be independent of rotational speed, intrinsic to HTS, and proportional to the cube of magnetic field inhomogeneity. Although the state-of-the-art analytical expression of hysteresis loss in SMBs captures the general physics of the loss mechanism, it ignores the periodicity of the magnetic field in one complete rotation of the bearing. In this paper, the analytical expression of hysteresis loss is modified, taking into account the impact of magnetic field periodicity and the distribution of loss over the bearing surface. The new expression is tested by performing spin-down experiments with magnets of different levels of inhomogeneity in an actual SMB environment. The impact of magnetic field inhomogeneity on the dynamic behaviour of the bearing is also investigated. The results show consistency between modified analytical calculations and experimental data.
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