A study on levitation force and its time relaxation behavior for a bulk superconductor-magnet system

Suzuki, Takashi; Araki, Shingo; Koibuchi, K.; Ogawa, Kōichi; Sawa, Kôichiro; Takeuchi, Kazuhiro; Murakami, Masato; Nagashima, K.; Seino, Hiroshi; Miyazaki, Yoshiki; Sakai, Naomichi; Hirabayashi, I.; Iwasa, Y.

doi:10.1016/j.physc.2008.05.140

Cited by 17 publications

(5 citation statements)

References 10 publications

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“…where B x (δ 0 ) represents the horizontal component of magnetic flux density, v is the unit volume of supercurrent flowing in the superconductor and δ 0 is the penetration depth, derived from [25]:…”

Section: Levitation Forcementioning

confidence: 99%

Magnetic levitation and guidance performance of Y–Ba–Cu–O and Gd–Ba–Cu–O bulk superconductors under low ambient pressure

Zhang¹,

Deng²,

Zhang³

et al. 2019

J. Phys. D: Appl. Phys.

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The high-temperature superconducting Maglev-evacuated tube transport (HTS Maglev-ETT) system has significant potential for practical applications. In order to employ HTS bulks in an ETT system, it is necessary to study the magnetic levitation and guidance performance of bulk superconductors under low ambient pressure conditions that are representative of those inside the tube. As a result, we have investigated the Maglev performance of Y–Ba–Cu–O (YBCO) and Gd–Ba–Cu–O (GdBCO) single grain, bulk superconductors under different ambient pressures of 100 kPa, 60 kPa and 20 kPa using a bespoke pressure-controlling platform, in which the superconductors were positioned above a Halbach permanent magnet guideway. The levitation forces under conditions of field-cooling (FC) and zero-field-cooling (ZFC) have been measured and analyzed. The guidance force for the FC case and the levitation force relaxation for the ZFC case were also measured. It was found from the experimental results that the Maglev performance of both types of bulk superconductor improves significantly by reducing the ambient pressure in their immediate working environment. The levitation forces of YBCO and GdBCO bulk superconductors were observed to increase by 11.6% and 4.4% in the case of FC, and by 20.3% and 13.7% in the case of ZFC, respectively, as the ambient pressure changed from 100 kPa to 20 kPa. An improvement of the guidance force and an inhibition of the levitation force relaxation were also observed for these materials. The supercooled liquid nitrogen cryogen in the low-pressure environment further reduces the temperature, which, in turn, increases the critical current density Jc of the bulk superconductors and improves their levitation performance. These results provide further evidence of the significant advantages of combining HTS Maglev with evacuated tube technologies as a key enabling feature of the HTS Maglev-ETT system. The data further indicate that YBCO bulk superconductors tend to be more sensitive to ambient pressure and temperature variation than GdBCO bulk superconductors. This difference essentially reflects the dependence of Maglev performance of HTS bulk superconductors on Jc when operating in a low-pressure environment.

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Section: Levitation Forcementioning

confidence: 99%

Magnetic levitation and guidance performance of Y–Ba–Cu–O and Gd–Ba–Cu–O bulk superconductors under low ambient pressure

Zhang¹,

Deng²,

Zhang³

et al. 2019

J. Phys. D: Appl. Phys.

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show abstract

“…It is assumed that the induced shielding currents flowing in the bulk body equal the critical currents. The δ used as integral range is given by the following relation: δ = (B y − B trap )(λμ 0 J c ) −1 [26], where λ is the Nagaoka coefficient determined by the configuration of a sample.…”

Section: Design Of An Hts Magnetic Levitation Unitmentioning

confidence: 99%

Driving models of high temperature superconducting linear synchronous motors and characteristic analysis

Jin¹,

Zheng

2011

Supercond. Sci. Technol.

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Driving models of high temperature superconducting (HTS) linear synchronous motors (LSM) are studied and extracted from the HTS LSM technology developed to date. An HTS LSM using an HTS bulk magnet secondary has been developed and presented for technical verification. The HTS LSM drive combined with an HTS bulk–permanent magnet guideway (PMG) system for magnetic levitation results in running without sliding friction and having the functions of self-levitation and self-guidance without the need for a compulsory active control system. In this paper, driving models of the HTS LSMs are introduced with numerical analysis results. Different magnetization methods are applied to obtain the HTS bulk magnets, and the HTS magnetization characteristics using those methods are identified. Two types of PMGs are designed and prepared whose magnetic field distributions are simulated and practically tested for comparison. Comprehensive experiments have been conducted on the HTS LSM drive. The practical results obtained show that the HTS LSM developed has applicable thrust characteristics without the conventional friction, and a better practical performance can be achieved by using HTS bulk magnets having a higher trapped magnetic field.

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“…Here, it is assumed that induced shielding currents flowing in the bulk body were equal to the critical currents. The δ used as integral range is given by the following relation [9] …”

Section: B Levitation Force and Guidance Force Analysismentioning

confidence: 99%

Design and electromagnetic analysis of a HTS linear synchronous motor

Liang

Jin

Guo

et al. 2009

2009 International Conference on Applied Superconductivity and Electromagnetic Devices

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Abstract-High temperature superconducting (HTS) linear synchronous motor (LSM) integrated with HTS magnetic levitation system, can realize self-levitation and self-guidance without any sliding friction, which will have important applications in many fields such as electromagnetic aircraft launch system, maglev transportation. This paper presents the design and electromagnetic analysis of a HTS LSM, which is levitated by a magnetic levitation system consisting of HTS bulkspermanent magnet (PM) guideways. Numerical analysis and magnetic field finite element analysis (FEA) methods are applied to analyze the thrust, levitation and guidance force characteristics, and the electromagnetic performance of HTS LSM under no-load and load situations are studied with the analysis results are given. Finally, the primary motor running testing results are provided.

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A study on levitation force and its time relaxation behavior for a bulk superconductor-magnet system

Cited by 17 publications

References 10 publications

Magnetic levitation and guidance performance of Y–Ba–Cu–O and Gd–Ba–Cu–O bulk superconductors under low ambient pressure

Magnetic levitation and guidance performance of Y–Ba–Cu–O and Gd–Ba–Cu–O bulk superconductors under low ambient pressure

Driving models of high temperature superconducting linear synchronous motors and characteristic analysis

Design and electromagnetic analysis of a HTS linear synchronous motor

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