The R&amp;D Project of HTS Magnets for the Superconducting Maglev

We have been designing and developing advanced Ag-sheathed Bi-2223 multifilamentary wires for the future applications to superconducting transformers of electric rolling stocks. Trial wires were twisted without remarkable degradation in the transport property for suppressing AC losses in a perpendicular magnetic field configuration. The AC losses were measured by a saddle-shaped pickup coil in a wide range of frequency up to a commercial frequency. The experimental results show that the AC loss per cycle has linear frequency dependence in a region of the practical amplitude of AC magnetic field for the transformers, where the excess loss may come from an electromagnetic coupling between the filaments. The hysteresis loss evaluated as a low frequency limit of the AC loss was also reduced with the decrease in the twist pitch, which may be considered as a similar effect to the so-called "twist effect" observed in in-situ Nb 3 Sn wires.Index Terms-AC loss, Bi-2223 wire, hysteresis loss, transformer of rolling stock, twist pitch.

Section: A Estimations Of Hysteresis Loss and Coupling Lossmentioning

confidence: 99%

Section: A Estimations Of Hysteresis Loss and Coupling Lossmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Development of Low-AC-Loss Bi-2223 Superconducting Multifilamentary Wires

Funaki¹,

Sasasige²,

Yanagida³

et al. 2009

“…According to their different operation principles and modes of HTS materials, they can be typically classified into the following categories: 1) HTSLSM with ordinary copper windings on the primary and zero-field-cooled (ZFC) HTS bulks on the secondary [8], [9], which is, in fact, a type of linear reluctance motor, (LRM), as will be explained later; 2) HTSLSM with ordinary copper windings on the primary and magnetized HTS bulk magnets or HTS coil magnets on the secondary [10]- [19]; 3) HTSLSM with HTS windings on the primary and conventional permanent magnets (PMs) on the secondary [20], [21]; 4) HTSLIM with HTS windings on the primary and ordinary induction conductors on the secondary [22].…”

Section: Introductionmentioning

confidence: 99%

High-Temperature Superconducting Linear Synchronous Motors Integrated With HTS Magnetic Levitation Components

Jin

Zheng

Guo

et al. 2012

High-temperature superconductors (HTSs) including HTS bulks and tapes have potential applications in linear motion drive and magnetic levitation/suspension systems generating substantial advantages over conventional ones. When an HTS linear motor is integrated with an HTS magnetic suspension subsystem, it can inherit both merits of HTS linear motion drive and HTS magnetic suspension simultaneously and can be applied into various fields, such as the maglev and electromagnetic aircraft launch systems (EMALSs). Based on different HTS aspects and arrangements, three modes of HTS linear synchronous motor (HTSLSM) integrated with HTS magnetic suspension subsystems have been proposed in this paper. To verify the modes for the design of a practical HTSLSM, the structural features of these systems are described, the magnetization characteristics to obtain HTS bulk magnets, the trapped-field attenuation characteristics of the HTS bulk magnet exposed to external traveling field, and the magnetic field distribution characteristics for different permanent-magnet guideways have been studied with experimental verification. Based on the study, a demonstration prototype of a single-sided HTSLSM integrated with HTS magnetic suspension subsystems has been developed. Its performance and thrust characteristics have been obtained by experimental measurements and compared with theoretical results. With regard to practical applications, two modes of double-sided HTSLSM integrated with HTS magnetic suspension subsystems have been designed for the maglev and EMALS, respectively, and then, the 2-D finiteelement-analysis models for the HTSLSMs were built to analyze their performance characteristics. The comprehensive simulations and experimental results constitute a framework for the structural and electromagnetic design of the HTSLSM integrated with HTS magnetic suspension for practical applications.

“…It was the first commercial maglev in the world [1]. The Railway Technical Research Institute (RTRI) of Japan and Central Japan Railway Company tested superconducting maglev having onboard high temperature superconducting (HTSC) levitation magnet successfully [2], [3]. The model of the maglev is MLX-01.…”

Section: Introductionmentioning

confidence: 99%

HTSC Levitation Experiment With AC Current Modeling After EDS Maglev

Cho

Bae²,

Shin

2007

The eddy current induced in the ground conductor by moving high field on board superconducting magnet forms the inductive levitation system. In other words, the change of magnetic flux linked in ground conductor is the source of the levitation force of electrodynamic suspension (EDS) system. As a preliminary study on the HTSC levitation magnet to develop high-speed maglev in Korea, instead of moving the magnet, in this paper, AC current was applied to the fixed superconducting magnet. The HTSC levitation tester, which models after electrodynamic suspension maglev, consists of one high-T c superconducting (HTSC) magnet, a reaction plate, and force measuring components. HTSC magnet was composed of series connected pancake coils wound with Bi-2223 wire. AC current was applied into the HTSC magnet with various frequencies and the levitation force was calculated and measured.