Predischarge Phenomena in Nonuniform Fields Caused by Lightning Impulse Voltages in SF(sub)6-$N_2$Mixtures

SF(sub)6-$N_2$혼합가스중에 뇌임펄스전압에 의해 형성된 불평등전장에서의 전구방전현상

  • 이복희 (인하대 공대 전기전자컴퓨터공학부 교수·공박) ;
  • 이경옥 (인하대 사범대학 부속고 교사·공박) ;
  • 백승권 (인하대 전자공학과 부교수·공박)
  • Published : 2001.06.01

Abstract

Predischarges in nonuniform electric field stressed by lightning impulse voltagesin SF(sub)6-$N_2$mixtures are initiated by streamer coronas. Due to field ehnancement at a protrusion point of electrodes new ionization processes occur and a precursor, which leads to a first leader, is created. The leader proceeds step by step to the opposite electrode and the final jump bridges the test gap. It was found that the predischarge is propagated with a leader mechanism of stepwise expansion from the predischarge current waveforms measured by a shunt. The predischarge current is closely related to the amplitude and polarity of applied voltages, the gas pressure and the gap geometry. The time intervals between step leaders for the positive and negative polarities were inversely proportional to V.P$^2$. When the gas pressure increases in the positive polarity, statistical time lag to statistical time lag to streamer corona inception increase slightly, but the formative time lag to flashover is significantly decreased.

Keywords

References

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