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Increase of breakdown voltage due to composite insulation in SF 6 gas
Author(s) -
Yoshida Tetsuo,
Miyagawa Masaru,
Ohshima Iwao,
Masaki Nobuo,
Yanabu Satoru
Publication year - 1991
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/eej.4391110605
Subject(s) - switchgear , materials science , breakdown voltage , composite material , epoxy , voltage , impulse (physics) , electric field , composite number , sulfur hexafluoride , dielectric strength , electrical engineering , dielectric , optoelectronics , chemistry , organic chemistry , quantum mechanics , engineering , physics
The breakdown characteristics using a hemispherical tip rod (10 ∼ 60 mm) molded with epoxy resin‐to‐plate gap in SF 6 gas up to 0.20 MPa was studied. The result shows that breakdown characteristics are classified into three regions ( A, B and C region) depending on gap length. In the A ‐region breakdown voltage is lowered compared with bare hemispherical tip rod‐to‐plate gap. In the B ‐region breakdown voltage is raised sharply with gap length and in the C ‐region it saturates. The maximum increase ratio of breakdown voltage in the B and C region are 1.95 times (ac) and 1.68 times (impulse) compared with a bare hemispherical tip rod‐to‐plate gap characteristic. The ratios depend on the diameter of the spherical tip rod and the thickness of epoxy resin. It is concluded that the increase of breakdown voltage is attributed to the synergism effect of the decrease of maximum electric field strength by epoxy resin and the suppression of field emission. The use of composite insulation reduces the gap length drastically in the gas‐insulated switchgear, for instance, C‐GIS (Cubicle‐type Gas‐Insulated Switchgear).