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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:17
Electrical, magnetic and thermal circuit modelling of a superconducting half-wave transformer rectifier flux pump using Simulink
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Article Number:Article 100053
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Abstract
Corresponding email:adam.francis@vuw.ac.nz
Superconducting flux pumps (FP) are capable of supplying superconducting circuits with high currents by additively supplying current over a number of cycles without introducing large amounts of heat into the cryogenic environment. Superconducting FPs can be broadly classified into two types: dynamo and transformer rectifier. Modelling the behaviour of these systems is an emerging field. In this work a model of a half wave magnetically switched transformer rectifier FP created in MATLAB/Simulink/Simscape is presented. Unlike existing models, the characteristics of all circuit elements are fully integrated allowing all superconducting elements to be accurately incorporated. The presented method uses pre-calculated look-up tables, populated with experimentally derived material qualities to simulate these superconducting elements. The thermal evolution of the switches, calculated simultaneously to the magnetic field switching interaction has also been included. This model is compared to the performance of a real world FP during the pumping of a load coil and is found to be accurate. Furthermore, the presented model illustrates how small amounts of heating at a magnetic switch can profoundly affect a FPs performance over many cycles.
cited:32
Bending performance analysis on YBCO cable with high flexibility
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Article Number:Article 100054
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Abstract
Corresponding email:m202071705@hust.edu.cn; qinjg@ipp.ac.cn
In order to utilize high-temperature superconducting Yttrium Barium Copper Oxide (YBCO) tapes to develop superconducting cables for high magnet field applications, it is critical to ensure the stable operation of the YBCO cable under challenging mechanical and thermal conditions. A new type of cable featuring the winding of YBCO and copper tapes around a spiral stainless steel tube has been proposed to increase flexibility and cooling. Experiments are performed to confirm that its critical current varies with the bending diameter. The cables wound with nine YBCO tapes in three layers show a critical current degradation of less than 5% for a bending diameter of 30 mm. The performance of the cable degrades as the number of wound layers increases. The critical current degradation of cable specimens wound from 15 tapes in five layers reached approximately 12% for a bending diameter of 30 mm. In addition, when compared to traditional CORC cable specimens, the developed cable specimens show better-bending flexibility and achieve a lower critical bending diameter. The finite element models show that the higher elasticity coefficient and lower plasticity of the stainless steel spiral tube results in a lower strain on the YBCO tapes of the HFRC cable than that of the CORC cable, and the maximum strain on the YBCO tapes of the HFRC cable was only about 10% of that of the CORC cable. Therefore, it is less likely that the YBCO tape in this type of cable will reach the irreversible strain limit during bending, resulting in a degradation in current carrying performance. Furthermore, the cooling efficiency can be improved by flowing the cooling medium inside the central core, which can significantly improve its thermal stability. These advantages indicate the possibility of using it in future high-field magnets with high current carrying capacity at fields greater than 15 T.
cited:16
Estimation of critical current density of bulk superconductor with artificial neural network
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Article Number:Article 100055
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Abstract
Corresponding email:yonghd@lzu.edu.cn
In the applications of superconducting materials, the critical current density is a crucial performance parameter. The conventional method of measuring of bulk superconductor is magnetization method. However, there are errors in the estimation of in the lower field, and the estimation is not applicable in the region where the magnetic field reverses. In this paper, of the bulk superconductor is determined by the hysteresis and magnetostriction loops with artificial neural network (ANN), respectively. Compared with double-output ANN, the critical current density obtained by single-output ANN is more accurate. Finally, the prediction results given by the hysteresis and magnetostriction loops are discussed.
cited:16
32 × 32 NbN SNSPD array based on thermally coupled row-column multiplexing architecture
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Article Number:Article 100056
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Abstract
Corresponding email:lihao@mail.sim.ac.cn; lxyou@mail.sim.ac.cn
We report a superconducting nanowire single-photon detector (SNSPD) array aiming for a near-infrared 1550-nm wavelength that consists of 32 × 32 nanowire pixels and an area of 0.96 mm × 0.96 mm. Unlike most reported large-scale SNSPD arrays with amorphous films, NbN superconducting nanowires are employed in our array, which allows the detector operation at 2.3 K provided by a compact two-stage Gifford–McMahon cryocooler. Thermally coupled row–column multiplexing is employed in our arrays to avoid current redistribution and loss of electrical signal occurring in the electrically coupled row–column architecture. The fabricated detector array shows a pixel yield of 94% and maximal intrinsic efficiencies of 77% and 96% at 1550 nm and 405 nm, respectively. The timing jitter and the thermal coupling probability are also investigated.
cited:12
A superconducting wireless energiser based on electromechanical energy conversion
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Article Number:Article 100057
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Abstract
Corresponding email:hongye.zhang@manchester.ac.uk; yang_tianhui@tju.edu.cn
A superconducting magnet (SM) can produce high magnetic fields up to a dozen times stronger than those generated by an electromagnet made of normal conductors or a permanent magnet (PM), and thus has attracted increasing research efforts in many domains including medical devices, large scientific equipment, transport, energy storage, power systems, and electric machines. Wireless energisers, e.g., high temperature superconducting (HTS) flux pumps, can eliminate the thermal load from current leads and arc erosion of slip rings, and are thus considered a promising energisation tool for SMs. However, the time-averaged DC output voltage in existing HTS flux pumps is generated by dynamic resistance: the dynamic loss is unavoidable, and the total AC loss will become significant at high frequencies. This study introduces a highly efficient superconducting wireless energizer (SWE) designed specifically for SMs. The SWE takes advantage of the inherent properties of a superconducting loop, including flux conservation and zero DC resistivity. Extensive theoretical analysis, numerical modelling exploiting the H-ϕ formulation, and experimental measurements were conducted to demonstrate the efficiency and efficacy of the novel SWE design. The electromechanical performance and loss characteristics of the SWE system have also been investigated. Compared to conventional HTS flux pumps, the proposed SWE has lower excitation loss, in the order of 10−1 mW, and thus can achieve a high system efficiency of no less than 95%. Furthermore, it has a simpler structure with higher reliability, considered ready for further industrial development. In addition to deepening the understating of the intricate electromechanical dynamics between magnetic dipoles and superconducting circuits, this article provides a novel wireless energisation technique for SMs and opens the way to step changes in future electric transport and energy sectors.
cited:19
Magnetic bearings with double crossed loops modelled with T-A formulation and electric circuits
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Article Number:Article 100058
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Abstract
Corresponding email:barbara.santos@eng.uerj.br
The application of High-Temperature Superconductor (HTS) coils made of coated conductors has been investigated for many years. A possible configuration for such coils is the jointless loop, also known as the ring coil. The double crossed loop coil (DCLC) has been successfully applied in superconducting magnetic bearings (SMBs). The design of SMBs with DCLCs requires flexible modelling to allow all parts of the device to be represented. This work proposes the T-A formulation with a thin-film approximation for modelling SMB with DCLCs in the finite element analysis framework. A 2D representation of the system is coupled with an external electric circuit to model the continuity of the lines that represent the parts of each jointless loop. To couple the T-A formulation and the circuit, an average of the total electric field, with both resistive and inductive components, is applied to the circuit. The total current computed by the circuit is applied to the T-A formulation. The proposed methodology was validated by comparison with levitation force experimental data. Two types of tests were simulated: five levitation force tests and three guidance force tests. It is shown that there is a limit to the behaviour of the levitation force related to the high-loss state. Below this limit, the stack of DCLCs behaves as an equivalent bulk. Beyond this limit, a high-loss state appears as a linear growth of the levitation force. It is also shown that this high-loss state in vertical displacement influences the lateral force.
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