Article
Physics, Applied
Robert Jurco, Anna Vaskuri, Benoit Cure, Alexey Dudarev, Matthias Mentink
Summary: We have developed a high-temperature superconducting flux pump using high-power metal-oxide-semiconductor field-effect transistors for switching. The pump consists of two commercial transformers and HTS coils, allowing for adjustable load current. A full-wave rectification and low-resistance HTS coils are used for enhanced efficiency. By controlling MOSFETs and analog electronics, precise control of the secondary coils is achieved. The pump also features custom-made copper-stabilized HTS current leads and a 3D-printed support structure for stability.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Hong Li, Wei Wang, Xiaojun Niu, Jun Zheng, Yunfei Gao, Hanxin Ye, Yuntian Zhang, Jiafu Wei, Hang Xu, Boyang Shen, Qun Zhou, Xueshan Liu, Yong Lei
Summary: This paper presents the preliminary charging test results of an HTS no-insulated double racetrack coil with the linear-motor type flux pump for a 16.9-kW-class HTS synchronous motor, where the CSED was optimized by testing different wavelengths of flux pumps and superconducting stator wires.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Engineering, Electrical & Electronic
Hanxin Ye, Wei Wang, Yuntian Zhang, Hong Li, Jiafu Wei, Hang Xu, Qun Zhou, Xueshan Liu, Yong Lei
Summary: This paper presents the fabrication and performance of a linear-motor type flux pump with a pumped current larger than 640 A, which is suitable for MRI magnets and HTS electric machines. The tested results show that this high-temperature superconducting flux pump can output direct current larger than 640 A at 77 K, with advantages such as smaller size and elimination of heat leakage compared to traditional power supplies. Increasing the length of the travelling wave region of this flux pump can potentially reach kilo-ampere level current output. The purpose of this paper is to test the reliability of the methodology for the large current HTS flux pump.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Engineering, Electrical & Electronic
Jun Ogawa, Satoshi Fukui, Tomohiro Nabeya, Kazuhiko Toshima, Yousuke Yanagi, Kenji Kawashima
Summary: A compact cryogen-free nuclear magnetic resonance (NMR) system is developed using a stacked high-temperature superconducting (HTS) bulk system. The uniformity of critical current density is important for NMR signal detection. In this study, a noncontact measurement method is proposed and investigated for evaluating the critical-current distribution of an HTS cylinder.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Article
Engineering, Electrical & Electronic
Lin Fu, Koichi Matsuda, Boyang Shen, Tim Coombs
Summary: The paper presents updates to the model for a traveling wave HTS electromagnetic flux pump, considering various sources of resistance including joint resistance, superconducting resistance, and dynamic resistance. Experiments were conducted to test the model's fit to the data.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Engineering, Electrical & Electronic
Lin Fu, Koichi Matsuda, Boyang Shen, Tim Coombs
Summary: In recent years, with the continuous development of High-temperature Superconductor (HTS) technology, the performance of HTS tape has been significantly improved. To use HTS instead of Low-temperature Superconductor (LTS) in MRI applications, the flux pumping method has been investigated.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Physics, Applied
Pengbo Zhou, Asef Ghabeli, Mark Ainslie, Francesco Grilli
Summary: Flux pumps provide a solution for contactless charging of HTS coils, and understanding the dynamics of the charging process is essential. This study proposes a methodology for coupling HTS coil and flux pump models using an electrical circuit. Validation of the approach shows good agreement with experimental results, and it is suggested to leave a margin between the operating current and the coil's critical current when using flux pumps.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Multidisciplinary
Moe M. Aye, Elmeri Rivasto, Mukarram Z. Khan, H. Rijckaert, H. Palonen, H. Huhtinen, Isabel Van Driessche, P. Paturi
Summary: The use of 50nm thick layers in multilayer structures increases J(c) by up to 40% compared to single layer BZO-doped films, with the best performance observed at high magnetic fields and temperatures, making them attractive for various electrical power applications in the future.
NEW JOURNAL OF PHYSICS
(2021)
Article
Physics, Applied
Lingfeng Zhu, Yinshun Wang, Xindan Zhang, Lecheng Wang
Summary: This study proposes a closed-loop high temperature superconducting magnet with thermal switches, which can operate in a persistent current mode. The magnet is made of rare-earth barium copper oxide tape and is magnetized by flux pump. Experimental results verify the feasibility of the magnet and a semi-analytical model is provided to calculate the transport current, which can explain and predict the saturation current of the magnet.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2022)
Article
Thermodynamics
Lingfeng Zhu, Yinshun Wang, Yuetong Guo, Wei Liu, Chengyang Hu
Summary: This paper investigates the current decay in high temperature superconducting (HTS) magnets exposed to non-uniform external AC magnetic fields, and studies the current compensation and field shielding methods for the magnet using a flux pump. An electro-magneto-thermal semi-analytical solution is established to accurately analyze the magnet's behavior, including the influence of temperature change. The proposed solution is proven to be accurate and efficient, providing guidance for the operations of closed-loop HTS magnets under external magnetic fields.
Article
Engineering, Electrical & Electronic
Han Zhang, Ye Yang, Yudong Jiang, Liang Bai, Xinsheng Yang, Yong Zhao
Summary: This follow-up study on the cryogen-free superconducting prototype generator with YBCO field windings focuses on optimizing the airgap magnetic field and improving the stability of the superconducting magnet. Upgrades to the support structure and vacuum chamber have been made to reduce the physical airgap and a new coil curing method has been applied to enhance stability. Performance properties of the optimized system and a comparison between FEM simulation and experimental results are presented.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Physics, Applied
A. Morandi, G. Russo, M. Fabbri, L. Soldati
Summary: This paper investigates the energy behavior of rotating flux pumps and finds that induced currents interact with the rotating magnet(s), converting a significant part of mechanical power into Joule heating. The study also explores the operational limits of the flux pump, showing that generator operation can only be achieved within a restricted range of current and voltage, with maximum power transfer and efficiency reached in the middle of the generator range.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Applied
Dachuan Chen, Yanbo Bi, Wei Wu, Yiwen Chen, Xin Yu, Siping Zhu, Chao Zhang, Zhiyong Hong, Longbiao Wang, Xiao-Fen Li
Summary: In this study, a miniaturized linear flux pump device was developed based on the principle of the upper limit for the output current of the traveling wave flux pumps. The experimental results showed that the critical current of the HTS tape has a significant effect on the flux pump output. Excitation tests on HTS coils demonstrated the charging/field supplement capability of the miniaturized flux pump.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Applied
Asef Ghabeli, Mark Ainslie, Enric Pardo, Loic Queval, Ratu Mataira
Summary: The high-T-c superconducting dynamo generates a DC voltage using the nonlinear resistivity of an HTS tape when exposed to a varying magnetic field. Two numerical models were used to examine the process of charging a coil by the dynamo, showing excellent agreement with an analytical method. The models captured the dynamic behavior of the charging process, including current ripples that could cause AC loss in the HTS dynamo.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2021)
Article
Energy & Fuels
Giacomo Russo, Antonio Morandi
Summary: High temperature superconductivity is considered a solution for lightweight, cost-effective, and high-power wind generators. This paper assessed the viability of using HTS dynamo and rectifier flux pumps for energizing the field coils, and found that using the dynamo flux pump can significantly reduce the cooling load.