Increase in the visual corona from floating electrodes

The corona and streamer discharges on a floating metallic rod located close to a high-voltage electrode were investigated under the application of bot h positive and negative 300/3000 mu s switching impulses. The distance betw een the floating rod and the high-voltage electrode was changed from a few millimetres to just fractions of a millimetre. An increase in the visual co rona is observed at the floating electrode when compared to a reference rod without series gap. The increase in visual corona seems to be more intense for negative than for positive polarity voltage impulses. A possible expla nation for this could be the difference in the temporal development of the electric field on the floating electrode and that of the rod without a seri es gap. (C) 1999 Elsevier Science B.V. All rights reserved.