uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Positive streamer discharges in air and along insulating surfaces: experiment and simulation
Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Division for Electricity and Lightning Research.
2002 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The power quality of modern society relies on the electrical properties of the dielectric insulators used in the power industry. Much research work has been conducted with an aim to understand and predict the insulating behaviour of such materials under different kinds of atmospheric conditions, but still there are many unsolved problems. In particular, there is a lack of knowledge concerning the electrohydrodynamic and electrophysical processes at the insulator surface and the surrounding medium. No detailed knowledge exists at present of the processes governing the development of electrical discharges along the surface of insulators.

With an aim to enhance the knowledge in this field in general and on the electrical performance of outdoor insulators in particular a detailed study of the positive streamer discharges in air and along dielectric surfaces was conducted. The study was also extended to gain more knowledge on the water drop initiated electrical discharges in air and the attachment of natural lightning flashes to a Franklin conductor.

In the first phase, the study was focused on positive streamer discharges propagating in air. The spatial distribution of the charge of a branched streamer discharge was obtained and the charge contained in a single streamer branch was quantified. In the second phase measurements and simulations of streamer discharges propagating along insulating surfaces were conducted with an aim to understand how the insulating surfaces interact with streamer discharges. In addition to quantifying the parameters of streamer discharges propagating along insulating surfaces, the results of these studies made it possible to separate and quantify the effects of the dielectric constant and the surface properties on the streamer discharges. In the third phase a comprehensive computer algorithm was developed to simulate 3-dimensional propagation of positive streamer discharges in air and along dielectric surfaces taking into account the branching effect.

The conditions necessary for the initiation of streamer discharges were applied to obtain the minimum strength of the background electric field required to initiate electrical discharges in the presence of water drops. In particular the study provided an explanation of how lightning flashes are initiated in thunderclouds in background electric fields as low as 200 kV/m. Finally, the study was extended to understand the performance of lightning conductors paying special attention to the influence of conductor radius and the streamer inception criterion.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis , 2002. , p. 88
Series
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1104-232X ; 777
Keywords [en]
Engineering physics
Keywords [sv]
Teknisk fysik
National Category
Other Engineering and Technologies
Research subject
Engineering Physics, with a direction to Atmospheric Discharges
Identifiers
URN: urn:nbn:se:uu:diva-2889ISBN: 91-554-5471-2 (print)OAI: oai:DiVA.org:uu-2889DiVA, id: diva2:162143
Public defence
2002-11-27, Siegbahnsalen, Uppsala, 13:15
Opponent
Available from: 2002-11-06 Created: 2002-11-06Bibliographically approved

Open Access in DiVA

fulltext(1071 kB)2932 downloads
File information
File name FULLTEXT01.pdfFile size 1071 kBChecksum MD5
a796cf5e938960f1abfc3fbfad9bfe187d231eeca8612daa6a24dcb92819fab4c7dfa49d
Type fulltextMimetype application/pdf
Buy this publication >>

By organisation
Division for Electricity and Lightning Research
Other Engineering and Technologies

Search outside of DiVA

GoogleGoogle Scholar
Total: 2932 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 1444 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf