The 1984 J. B. Whitehead Memorial Lecture the Physics of Partial Discharges in Solid Dielectrics

摘要: The physical processes occurring during partial discharges in voids dielectrics have been studied utilizing fast oscilloscopic techniques to observe the buildup and decay of current as a function time for single discharges. A key parameter is overvoltage at breakdown, determined time-dependent voltages by rate rise voltage statistical lag. Two distinct types discharge identified, named ?Townsendlike? ?streamerlike?, mechanisms responsible their development proposed. relationship between current-time pulse shapes well magnitudes (charge per discharge) various parameters such overvoltage, void size, dielectric thickness permittivity explored. conditions governing transition two examined quantitatively. streamer propagation Lichtenberg figure has studied. Measurements lags made significant paramters examined. usefulness these results connection with future studies chemical degradation insulating materials are discussed.