Breakdown of mineral oil: effect of electrode geometry and rate of voltage rise

Mark Wilson, Igor Timoshkin, M Given, Scott MacGregor, Tao Wang, M.A. Sinclair, K.J. Thomas, J.M. Lehr

Research output: Contribution to journalArticle

10 Citations (Scopus)
165 Downloads (Pure)

Abstract

Experimental data on the propagation of streamers in mineral oil is important for the design of high-voltage systems in the power and pulsed-power industries. In the present study, breakdown voltages and pre-breakdown delay times were measured for planeparallel electrodes, and for two non-uniform electrode arrangements. For each geometry, the breakdown characteristics were determined for impulses of rise-time 100 ns, and also rise-time 1 μs. The maximum rate of voltage rise (dV/dt) was 4 MV/μs. For the non-uniform geometries with inter-electrode gap length of 8.5 mm, the time to breakdown was 2.5-3 times longer for impulses of rise-time 1 μs than for 100 ns risetime.
The time-to-breakdown data suggest that streamer propagation velocity increases with higher values of dV/dt. For example, the estimated propagation velocity for pinplane geometry with a 1 μs rise-time is 10-12 km/s. At 100 ns rise-time for the same electrode geometry, the average propagation velocity exceeds 40 km/s. The results are compared with data previously generated in parallel liquid-solid gaps, and it is concluded that the time to breakdown is longer, and that higher applied fields are required to initiate breakdown, in open oil gaps compared to the case when a solid spacer is present. The results presented are intended to provide reference data for designers of oil-immersed, high-voltage systems such as power transformers and pulsed-power supplies.
Original languageEnglish
Pages (from-to)1657-1664
Number of pages8
JournalIEEE Transactions on Dielectrics and Electrical Insulation
Volume19
Issue number5
DOIs
Publication statusPublished - 2 Oct 2012

Keywords

  • breakdown voltage
  • dielectric liquids
  • dielectric breakdown
  • mineral oil
  • electrode geometry
  • voltage rise
  • rate
  • effect

Fingerprint Dive into the research topics of 'Breakdown of mineral oil: effect of electrode geometry and rate of voltage rise'. Together they form a unique fingerprint.

  • Cite this