| Project/Area Number |
08455129
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | Yokohama National University |
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Principal Investigator |
TSUKAMOTO O. Yokohama National University, Faculty of Eng., Professor, 工学部, 教授 (30017975)
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| Co-Investigator(Kenkyū-buntansha) |
AMEMIYA N. Yokohama National University, Faculty of Eng., Asociate Professor, 工学部, 助教授 (10222697)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1998: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1997: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1996: ¥4,000,000 (Direct Cost: ¥4,000,000)
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| Keywords | High temperature superconductor / AC loss / Multifilament wire / AC transport current loss / n value / Bi silver sheathed tape / Assembled conductor / 高温酸化物超伝導体 / 交流損失 / テープ線材 / イットリウム線材 / 電力ケーブル / 変圧器 / 超伝導電力ケーブル / 高温酸化物超伝導 / 超伝導フィラメント / 交流劣化現象 / 磁気的不安定性 / 磁束フロー |
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| Research Abstract |
In this project we performed the following studies to clarify methods to reduce AC losses of high temperature superconducting (LHS) wires.
1) Measurement of AC losses of HTS wires in DC and AC external magnetic field.
We developed a method to measure AC transport current losses of superconducting wires in the external magnetic field avoiding spurious losses. Using this method, we measured the AC etransport current losses of various HTS wires, such as Bi 2223 silver sheathed tapes, YBCO tapes and Bi22l2 rod. As the results, we found that in many case there were significant discrepancies between the measured data and values calculated from Norris formula which was widely accepted. to well agree with measurement. We also measured the transport current AC loss of a wire in assembled, conductor and found that the AC loss was decreased due to the magnetic field produced by transport currents of wires adjacent to the wire whose loss was measured. This result suggests that the transport current loss can be reduced by proper design of wire structure.
2)Modeling the electromagnetic behavior of LTS wire to calculated the AC loss.
We made a theoretical model to quantitatively calculate the AC losses of HIS wires by modifying the theoretical model developed for the low temperature superconductor (LTS). The theoretical model for HTS wires was verified by the result of the study 1).
3)Proposing methods to design a wire with low AC losses.
Based on the theoretical model formulated by the study 2), we proposed methods to reduce the AC losses. Validity of the methods were demonstrated by using LTS wires and assembled conductor simulating a wire with low loss structure.
By above studies, we consider the purpose of the project was well fulfilled.
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