1992 Fiscal Year Final Research Report Summary
Basic Research on Protection of Distribution Lines through the Waveform Analysis of Surges caused by Lightning Discharges
| Project/Area Number |
02805034
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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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 | Ishikawa National College of Technology |
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Principal Investigator |
SAKURANO Hitoshi Ishikawa National College of Technology, Dpt.of Electrical Engineering, Associate Professor, 電気工学科, 助教授 (50042932)
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| Project Period (FY) |
1990 – 1992
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| Keywords | Lightning surge / Winter lightning discharge / Ground flash location / VTR camera / Capacitive voltage detector / Digital memory / Regional distribution of electric field / Zero-phase-sequence component |
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| Research Abstract |
Obtained results in this project are summarized as the following five items ;
1. Observations of the electric field intensity on the ground by measuring the point discharge current have been performed at Ishikawa National College of Technology, and several sites around the College in winter. The frequency of occurrence of positive flash nearly the same as that of negative one in winter lightning discharges.
2. A graphical method was developed to presume regional destribution of the electric field under the winter thundercloud on the basis of observed records. The accurated stroke locations were determined by the double-quarter VTR observations. These have struck positions within distance of about 1 km from the boundary between the positive and negative areas of the electric field on the ground.
3. Lightning characteristics in the flat ground mentioned above were compared with one at Mt. Okushishiku and Mt. Houtatsu in Hokuriku district.
4. Lightning surges induced on the three distribution feeders were measured by a memory recorder with 4 channel at the Unoke substation. A waveform of zero-phase-sequence currents induced on the line near the cloud-to ground flash point is different from one on the other lines.
5. The capacitive voltage detector using an optical fiber system was produced as an experiment. The improvement in design will be achieved for recording a precise waveform in future.
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