| Project/Area Number |
60850048
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
電力工学
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| Research Institution | Hokkaido University |
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Principal Investigator |
TAGASHIRA Hiroaki Hokkaido University, Gaculty of Engineering , Prof,, 工学部, 教授 (10001174)
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| Co-Investigator(Kenkyū-buntansha) |
SHIMOZUMA Mitsuo Hokkaido University, College of Medical. Technology,Instructor, 医療技術短期大学部, 助手 (70041960)
SATO Nobuyasu Hokkaido University, Faculty of Engineering,Instructor, 工学部, 助手 (20001290)
KANEKO Yoshimatsu Hokkaido University, Faculty of Engineering,Instructor, 工学部, 助手 (90001271)
SAKAI Yousuki Hokkaido University, College of Medical Technology , Prof, 医療技術短期大学部, 教授 (20002199)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1986: ¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 1985: ¥3,800,000 (Direct Cost: ¥3,800,000)
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| Keywords | Gas Insulation / Gas Mixtures / Vapor-Mist Dielectrics / Gas Insulated Cubicle / GIS / Synergism / <SF_6> / ベーパーミスト誘電体 / c-GIS / 絶縁破壊特性 / 実効電離係数 / 電子付着係数 |
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| Research Abstract |
Gas Insulated Cubicle (C-GIS) is a popularized version of the conventional <SF_6> insulated switchgears. Economy is pursured by reducing the gas pressure to or around that of atmospheric air and thus by making the structure of container simpler with C-GIS. Since the gas pressure is reduced the breakdown field strength would be low with C-GIS, although other merits may be inherited from GIS. The purpose of the present project is to find possibilities of improving the breakdown strength by utilizing the synergism of <SF_6> and fluorocarbon gas mixtures. A possibility of attining the purpose by using vapor-mist dielectrics is also tested experimentally.
The main results are as follows.
1) Synergism in breakdown strength of <SF_6> and c- <C_4F_8> and <SF_6> and 1- <C_3F_6> gas mixtures is confirmed experimentally. The breakdown strength is about 30 % higher than that of either of the single gases.
2) The cause of the synergism is clarified experimentally for the first time : it is due to the reduction of the effective ionization coefficient <alpha> of the mixture. 3) The pressure dependence of the breakdown field strength of c- <C_4> <F_8> gas is discovered for the first time. The breakdown strength is larger with higher gas pressure. The cause is found due to the decrease of the effective ionization coefficient with increasing pressure.
4) Atmospheric pressure air plus <C_6> <F_(14)> vapor-mist is found to have more than 4 times larger breakdown strength of the air, and the air plus <(C_4F_9)_3> N mist is found to endure more than 50 minutes after the mist generation is ceased, reducing greatly the duty of the generator, both for the first time. These results strongly suggest the effectiveness of vapor-mist dielectric insulation for C-GIS.
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