Mechanisms of impulse breakdown in liquid: the role of Joule heating and formation of gas cavities

V.M. Atrazhev, V.S. Vorob'ev, I.V. Timoshkin, M.J. Given, S.J. MacGregor

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

The impulse dielectric behaviour of insulating liquids is of significant interest for researchers and engineers working in the field of design, construction and operation of pulsed power systems. Analysis of the literature data on transformer oils shows that potentially there are several different physical processes which could be responsible for dielectric breakdown by sub-microsecond and microsecond impulses. While for short, sub-microsecond impulses ionisation (plasma streamer) is likely to be the main breakdown mechanism, for longer impulses, thermal effects associated with Joule heating start to play an important role. The present paper is provides a theoretical analysis of the latter mechanism in dielectric liquids of different degrees of purity stressed with high voltage impulses with duration sufficient to cause local heating, evaporation and formation of pre-breakdown gas bubbles. The proposed model is based on the assumption that dielectric breakdown is developed through percolation channels of gas bubbles and the criterion of formation of these percolation chains is obtained. In order to test the developed model, the breakdown field-time characteristics have been calculated for the liquid with chemical composition close to that of transformer oils but with known thermodynamic characteristics (n-hexane). Its dielectric strength has been obtained as a function of externally applied pressure and temperature. The analytical results show a good agreement when compared with the experimental data available in the literature.
LanguageEnglish
Pages2644-2651
Number of pages7
JournalIEEE Transactions on Plasma Science
Volume38
Issue number10
DOIs
Publication statusPublished - Oct 2010

Fingerprint

Joule heating
impulses
breakdown
cavities
liquids
gases
transformers
bubbles
oils
engineers
temperature effects
high voltages
chemical composition
purity
evaporation
ionization
thermodynamics
heating
causes
temperature

Keywords

  • dielectric liquids
  • volt-time characteristics
  • impulse breakdown

Cite this

@article{8ae1733fa0ad4949b89420f2bfb0b562,
title = "Mechanisms of impulse breakdown in liquid: the role of Joule heating and formation of gas cavities",
abstract = "The impulse dielectric behaviour of insulating liquids is of significant interest for researchers and engineers working in the field of design, construction and operation of pulsed power systems. Analysis of the literature data on transformer oils shows that potentially there are several different physical processes which could be responsible for dielectric breakdown by sub-microsecond and microsecond impulses. While for short, sub-microsecond impulses ionisation (plasma streamer) is likely to be the main breakdown mechanism, for longer impulses, thermal effects associated with Joule heating start to play an important role. The present paper is provides a theoretical analysis of the latter mechanism in dielectric liquids of different degrees of purity stressed with high voltage impulses with duration sufficient to cause local heating, evaporation and formation of pre-breakdown gas bubbles. The proposed model is based on the assumption that dielectric breakdown is developed through percolation channels of gas bubbles and the criterion of formation of these percolation chains is obtained. In order to test the developed model, the breakdown field-time characteristics have been calculated for the liquid with chemical composition close to that of transformer oils but with known thermodynamic characteristics (n-hexane). Its dielectric strength has been obtained as a function of externally applied pressure and temperature. The analytical results show a good agreement when compared with the experimental data available in the literature.",
keywords = "dielectric liquids, volt-time characteristics, impulse breakdown",
author = "V.M. Atrazhev and V.S. Vorob'ev and I.V. Timoshkin and M.J. Given and S.J. MacGregor",
year = "2010",
month = "10",
doi = "10.1109/TPS.2010.2046337",
language = "English",
volume = "38",
pages = "2644--2651",
journal = "IEEE Transactions on Plasma Science",
issn = "0093-3813",
number = "10",

}

Mechanisms of impulse breakdown in liquid: the role of Joule heating and formation of gas cavities. / Atrazhev, V.M.; Vorob'ev, V.S.; Timoshkin, I.V.; Given, M.J.; MacGregor, S.J.

In: IEEE Transactions on Plasma Science, Vol. 38, No. 10, 10.2010, p. 2644-2651.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Mechanisms of impulse breakdown in liquid: the role of Joule heating and formation of gas cavities

AU - Atrazhev, V.M.

AU - Vorob'ev, V.S.

AU - Timoshkin, I.V.

AU - Given, M.J.

AU - MacGregor, S.J.

PY - 2010/10

Y1 - 2010/10

N2 - The impulse dielectric behaviour of insulating liquids is of significant interest for researchers and engineers working in the field of design, construction and operation of pulsed power systems. Analysis of the literature data on transformer oils shows that potentially there are several different physical processes which could be responsible for dielectric breakdown by sub-microsecond and microsecond impulses. While for short, sub-microsecond impulses ionisation (plasma streamer) is likely to be the main breakdown mechanism, for longer impulses, thermal effects associated with Joule heating start to play an important role. The present paper is provides a theoretical analysis of the latter mechanism in dielectric liquids of different degrees of purity stressed with high voltage impulses with duration sufficient to cause local heating, evaporation and formation of pre-breakdown gas bubbles. The proposed model is based on the assumption that dielectric breakdown is developed through percolation channels of gas bubbles and the criterion of formation of these percolation chains is obtained. In order to test the developed model, the breakdown field-time characteristics have been calculated for the liquid with chemical composition close to that of transformer oils but with known thermodynamic characteristics (n-hexane). Its dielectric strength has been obtained as a function of externally applied pressure and temperature. The analytical results show a good agreement when compared with the experimental data available in the literature.

AB - The impulse dielectric behaviour of insulating liquids is of significant interest for researchers and engineers working in the field of design, construction and operation of pulsed power systems. Analysis of the literature data on transformer oils shows that potentially there are several different physical processes which could be responsible for dielectric breakdown by sub-microsecond and microsecond impulses. While for short, sub-microsecond impulses ionisation (plasma streamer) is likely to be the main breakdown mechanism, for longer impulses, thermal effects associated with Joule heating start to play an important role. The present paper is provides a theoretical analysis of the latter mechanism in dielectric liquids of different degrees of purity stressed with high voltage impulses with duration sufficient to cause local heating, evaporation and formation of pre-breakdown gas bubbles. The proposed model is based on the assumption that dielectric breakdown is developed through percolation channels of gas bubbles and the criterion of formation of these percolation chains is obtained. In order to test the developed model, the breakdown field-time characteristics have been calculated for the liquid with chemical composition close to that of transformer oils but with known thermodynamic characteristics (n-hexane). Its dielectric strength has been obtained as a function of externally applied pressure and temperature. The analytical results show a good agreement when compared with the experimental data available in the literature.

KW - dielectric liquids

KW - volt-time characteristics

KW - impulse breakdown

UR - http://www.scopus.com/inward/record.url?scp=77958609102&partnerID=8YFLogxK

UR - http://dx.doi.org/10.1109/TPS.2010.2046337

U2 - 10.1109/TPS.2010.2046337

DO - 10.1109/TPS.2010.2046337

M3 - Article

VL - 38

SP - 2644

EP - 2651

JO - IEEE Transactions on Plasma Science

T2 - IEEE Transactions on Plasma Science

JF - IEEE Transactions on Plasma Science

SN - 0093-3813

IS - 10

ER -