A. Saker et P. Atten, POTENTIAL DISTRIBUTION ALONG SINGLE NEGATIVE CREEPING STREAMER IN TRANSFORMER OIL, IEE proceedings. A, Science, measurement and technology, 140(5), 1993, pp. 375-381
A needle immersed in transformer oil is located just above a sheet of
glass the opposite surface of which is conducting. By applying steps o
f high voltage, streamers are generated which propagate radially with
numerous branches. A technique for guiding the discharges gives single
quasirectilinear streamers, which allows more accurate investigation.
The characteristics of these discharges (mean propagation velocity, f
inal extension, electric current and charge) are determined and the me
asured charge is compared with the predictions of two simple models. T
his indicates that the streamer channels are not equipotential. A capa
citive probe technique with associated optical fibres allows one to ac
curately determine the spatio-temporal variation of the potential alon
g the streamer channels.