Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • 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
Diagnosis of moisture in oil/paper distribution cables-part II: Water penetration in cable insulation-experiment and modeling
KTH, Superseded Departments, Electrical Systems.
KTH, Superseded Departments, Electrical Systems.
2004 (English)In: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 19, no 1, 15-20 p.Article in journal (Refereed) Published
Abstract [en]

Dynamics of water penetration in mass impregnated cable insulation has been studied. For experimental purposes, artificial damage has been inflicted to a 40-cm-long cable sample and water ingress has been continuously monitored by frequency response measurements. A similar experiment has been conducted on 2.8-m-long cable sample, where both frequency response and time-domain reflectometry (TDR) measurements have been performed. After termination of both experiments, actual moisture content has been measured radially and axially. Based on dielectric measurements, a model of water ingress has been developed and diffusion coefficients have been estimated for mass impregnated cable paper.

Place, publisher, year, edition, pages
2004. Vol. 19, no 1, 15-20 p.
Keyword [en]
Dielectric response, Karl Fischer titration, Mass impregnated cable, Moisture content, Oil paper insulation
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
URN: urn:nbn:se:kth:diva-5122DOI: 10.1109/TPWRD.2003.820430ISI: 000187886300003Scopus ID: 2-s2.0-0348129456OAI: oai:DiVA.org:kth-5122DiVA: diva2:7906
Note
QC 20100908Available from: 2005-05-18 Created: 2005-05-18 Last updated: 2017-12-04Bibliographically approved
In thesis
1. Techniques for Localization of Insulation Degradation along Medium-Voltage Power Cables
Open this publication in new window or tab >>Techniques for Localization of Insulation Degradation along Medium-Voltage Power Cables
2005 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

Time Domain Reflectometry (TDR) has been used for localization of transmission line discontinuities in diverse applications. Various challenges have to be addressed when applying TDR for localization of insulation degradation in power cables. The dominant problem is that TDR detects reflections coming from insulation changes, but it also records reflections related to geometrical irregularities along the cable length and, in some cases, surrounding medium variations. It is realized that one can compare TDR measurements before and after changes have occurred or have been induced in the aged sections. Thus the signals from the deteriorated insulation can be distinguished from other reflections that are constant.

The measurement technique to localize water-treeing in cross-linked polyethylene (XLPE) insulation is based on the voltage nonlinearity of water trees. TDR measurements have been performed before, after and during the application of high AC voltages. The high stresses affect the cable characteristic impedance and speed of wave propagation in the water-treed region. The possibility to detect local changes in the velocity of wave propagation has been presented as a technique for localization of insulation ageing. Localization of impedance changes related to water treeing and water ingress in mass impregnated paper insulated cables has also been achieved.

To characterize the power cables in the high frequency domain two parameter extraction methods have been developed. The first one uses TDR measurements and analyses short pulse propagation along the cable. The second one is based on the S-parameter measurements in the frequency domain. The methods extract the complex propagation constant and the characteristic impedance, as well as the LCRG Telegrapher's Equation parameters for the frequencies between 300 kHz and 300 MHz.

The dependence of the high frequency power cables properties on the metallic screen design and cable surrounding medium has been studied. The cable characteristics are modeled using time- and frequency-domain numerical simulations. This is required due to the complex spiralized structure of the outer metallic screen. It is established that this screen design causes a dependence of the cable characteristics on the surrounding medium.

Place, publisher, year, edition, pages
Stockholm: KTH, 2005. xii, 114 p.
Series
Trita-ETS, ISSN 1650-674X ; 2005:03
Keyword
Electrical power technology, Attenuation measurement, cross-linked polyethylene insulation, discontinuities, localization, mass-impregnated insulation, numerical analysis, parameter estimation, power cable metallic screen, scattering parameters, time domain reflectometry, velocity measurements, water treeing, Elkraftteknik
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-207 (URN)91-7178-044-0 (ISBN)
Public defence
2005-05-27, E1, Lindstedtsvägen 3, Stockholm, 10:00
Opponent
Supervisors
Note
QC 20101012Available from: 2005-05-18 Created: 2005-05-18 Last updated: 2010-10-12Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Eriksson, RolandPapazyan, Ruslan
By organisation
Electrical Systems
In the same journal
IEEE Transactions on Power Delivery
Other Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 146 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • 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