GIS中エポキシ絶縁物の直流残留電荷に対する耐圧性能の評価 Evaluation of Withstand Performance for Epoxy Insulator under Residual DC Charge in GIS
With the rationalization of specifications, a gas-insulated switchgear (GIS) has been miniaturized in recent years. GIS for AC is designed so that it can resist an AC test voltage and lightning impulse (LI) test voltage. However, a test is not made for the residual DC voltage occurring in an AC GIS spacer when switchgear operates. The residual DC voltage is also not sufficiently investigated in this case. In the DC electric field, the electrified charge strengthens the creeping electric field (E<sub>t</sub>) of an insulator. The withstand performance of an insulating spacer to DC depends on the maximum creeping electric field (E<sub>tmax</sub>). When the volume resistivity in the surface layer of an insulating spacer is non-uniform, E<sub>t</sub> is strengthened at the non-uniform point and the corresponding point usually becomes E<sub>tmax</sub>. In this paper, the change in E<sub>tmax</sub> was investigated from experimental results and analysis when a point at which volume resistivity is non-uniform exists in the surface layer of an insulating spacer. Moreover, creeping flashover characteristics were also investigated and evaluated when a LI voltage is superimposed and applied on and to the residual DC voltage.
- 電気学会論文誌. B, 電力・エネルギー部門誌 = The transactions of the Institute of Electrical Engineers of Japan. B, A publication of Power and Energy Society
電気学会論文誌. B, 電力・エネルギー部門誌 = The transactions of the Institute of Electrical Engineers of Japan. B, A publication of Power and Energy Society 128(5), 728-734, 2008-05-01
The Institute of Electrical Engineers of Japan