Gas Insulated Self Breakdown Spark Gaps: Aspects on Low Scattering and Long Lifetime Switching
W. Frey, M. Sack, R. Wuestner and G. Mueller
Forschungszentrum Karlsruhe GmbH, Inst. f. Hochleistungsimpuls- und Mikrowellentechnik (IHM), Hermann-v-Helmholtz Platz, 1, DE-76344 Eggenstein Leopoldshafen, Germany
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The influence of the electric field distribution between the electrodes and the seed electron generation rate on the scattering of the breakdown voltage of SF6-insulated spark gaps was investigated. The breakdown voltage scattering considerably can be reduced by applying large gap volume, uniform: field electrode profiles instead of spherical shaped electrodes. Moreover, uniform field electrode profiles exhibit an uniform discharge probability in the entire gap volume and following an almost uniform erosion of electrode material along the electrode's surface. This preserves electrode shape and switching performance of the spark gap for a long maintenance free lifetime. Breakdown voltage scattering further can be reduced by increasing the seed electron generation in the gap by an auxiliary corona discharge adjacent to the main gap. The experimental observations are discussed on the basis of the volume time law for discharge initiation.
DOI: 10.12693/APhysPolA.115.1016
PACS numbers: 52.75.Kq, 52.80.Mg