2004 Fiscal Year Final Research Report Summary
Research on Magnetization and Demagnetization of Bulk HTS using Increasing and Decreasing Oscillatory Pulse Magnetic Field
| Project/Area Number |
14550275
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
電力工学・電気機器工学
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| Research Institution | Seikei University |
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Principal Investigator |
ISHIGOHKA Takeshi Seikei University, Faculty of Engineering, Professor, 工学部, 教授 (30054373)
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| Co-Investigator(Kenkyū-buntansha) |
NINOMIYA Akira Seikei University, Faculty of Engineering, Assistant, 工学部, 助手 (50119351)
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| Project Period (FY) |
2002 – 2004
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| Keywords | bulk HTS / pulse magnetization / pulse demagnetization / on-site magnetization / increasing oscillatory field / decreasing oscillatory field / AC / DC combined field |
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| Research Abstract |
In this research, we proposed the use of an increasing and decreasing oscillatory magnetic field for the on-site magnetization of bulk high temperature superconductor (HTS) as a compact method. The adopted method is; (a)using a small synchronous generator as a variable AC voltage source, (b)utilizing the transient characteristics of a LC resonant circuit, (c)using arbitral wave-shape generator composed of semiconductor circuits. The obtained results are summarized as follows:
(1) Using AC oscillatory magnetic field followed by gradually decreasing DC magnetic field, about 2 times higher magnetization was obtained.
(2) Applying a gradually decreasing AC magnetic field on a bulk HTS, the originally magnetized field of about 700 Gauss was efficiently demagnetized to the level of lower than 10-20 Gauss, which is about 1/700 of the original magnetization field.
(3) It was confirmed that the gradually increasing oscillatory current can be obtained by applying a constant magnitude resonant frequency voltage on a LC series resonant circuit.
(4) Using an IGBT-based inverter circuit we manufactured in our laboratory the arbitral wave-shape generator. Using this generator, good magnetization results were obtained.
(5) Using a combined magnetic field composed of AC and DC ones, higher efficiency magnetization was obtained.
In this experiment, the maximum obtained field is about 700 Gauss, which is relatively low for the actual application. However, the fundamental merit of AC/DC combined magnetic field is demonstrated. And, this technology can be easily extended to the higher magnetic field region of 5-10 T.
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Research Products
(10 results)
