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Barrier effect under nonuniform field in atmospheric pressure SF 6 gas
Author(s) -
Miyagawa Masaru,
Yoshida Tetsuo,
Masaki Nobuo,
Ohtake Shiro,
Ohshima Iwao
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.4391110707
Subject(s) - switchgear , atmospheric pressure , voltage , arc flash , impulse (physics) , electric field , sulfur hexafluoride , equipotential , materials science , electrical engineering , electrode , mechanics , surface charge , chemistry , atomic physics , analytical chemistry (journal) , composite material , physics , meteorology , engineering , organic chemistry , quantum mechanics , chromatography
Generally, it is known that insertion of a barrier under a nonuniform field in air increases the flashover voltage. This is called the barrier effect. However, there are many uncertainties that remain to be clarified about the barrier effect in SF 6 gas. Therefore, the influence of the barrier shapes and positions on the flashover voltage for the lightning impulse voltages and voltages (50 Hz) is examined by inserting a barrier between a hemispheric‐end rod and a plate in SF 6 gas under near‐atmospheric pressure. As a result, the following findings were obtained:. (1) Insertion of a disk‐shaped barrier reduces the flashover voltage; a cup‐shaped barrier whose surface curves almost along the equipotential line increased the flashover voltage by 30 to 40 percent;. (2) trapped charge on the barrier surface is of the same polarity as the applied voltage and the magnitude of positive charge was greater than that of negative charge. It was found also that there is a correlation between the amount of trapped charge and the flashover voltage; and. (3) application of a barrier under a nonuniform field in the atmospheric pressure SF 6 gas helps reduce the size of, for example, a cubic‐type gas‐insulated switchgear.