| Project/Area Number |
09555085
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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 | 展開研究 |
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| Research Field |
電力工学・電気機器工学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
HIDAKA Kunihiko The University of Tokyo, School of Engineering, Professor, 工学系研究科, 教授 (90181099)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUOKA Shigeyasu The University of Tokyo, School of Engineering, Research Associate, 工学系研究科, 助手 (10114646)
CHIBA Masakuni The University of Tokyo, School of Engineering, Research Associate, 工学系研究科, 助手 (20011140)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥8,600,000 (Direct Cost: ¥8,600,000)
Fiscal Year 1998: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1997: ¥6,700,000 (Direct Cost: ¥6,700,000)
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| Keywords | Fiber / Crystal / Pockels Effect / High Voltage / Measurement / Optical Method / Potentical Difference / Electric Field |
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| Research Abstract |
Measuring of the high voltages generally needs extra devices such as capacitive or resistive dividers in combination with voltage transformers. These conventional techniques have some limitation in frequency bandwidth, insulation and nonlinearity at the dynamic behavior.
In this research a new Pockels electro-optic sensor applied directly to measure high voltages without the aid of any additional voltage divider are developed. It uses a fiber Pockels crystal in a longitudinal modulation arrangement. Main results obtained are as follows :
1. A fiber Pockels crystal of Bi_4Ge_3O_<12>(BGO), which is 0.9 mm in diameter and 40 mm in length, has been grown. The sensor system consists of the fiber BGO crystal, He-Ne laser of 632.8nm as a light source, large core optical fibers in communication link, a PIN photodiode detector, and a high voltage SF_6 gas insulated vessel.
2. The measured half-wave voltage, which corresponds to the maximum measurable voltage of the sensor system, as 162 kV.Its value is 5 times lager than the theoretically predicted value. This characteristic is considered to be useful for measuring high voltages.
3. The performance of the sensor system was tested for dc, ac, lightning impulse and step waveform applied voltages up to 50 kV.
4. An oscillatory component in the range of hundreds kHz, which was observed in the tail part of the lightning impulse measurements using conventional Pockels sensors, is successfully eliminated with the present sensor system.
5. The sensor system responds to a fast step voltage of 3 ns in rising time which corresponds to a frequency bandwidth of 116 MHz. Finally, the experimental results show a flat frequency response of this sensor in a wide frequency range from dc to more than 100 MHz.
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