Flashover formation and expansion mechanisms on the surfaces of different dielectrics immersed in transformer oil have been numerically analyzed. Streamers emanating from a needle electrode tend to transform to surface flashovers if the immersed dielectric permittivity is higher than the liquid permittivity and/or the dielectric interfacial surface cuts the path of the streamer. Perpendicular interface of the immersed dielectric impedes the breakdown by deflecting the streamer and slowing down the surface flashover. The parallel dielectric interface, however, assists the breakdown by regulating the surface flashover velocity to an approximately constant value (∼10 km/s).
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机译:数值分析了浸在变压器油中的不同电介质表面上的闪络形成和膨胀机理。如果浸入的介电常数高于液体介电常数和/或介电界面切割了流光的路径,则从针状电极发出的流光趋向于转换为表面闪络。浸入式电介质的垂直界面通过偏转拖缆并减慢表面闪络来阻止击穿。然而,平行的介电界面通过将表面闪络速度调节到大约恒定值(〜10 km / s)来辅助击穿。
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