kth.sePublikationer
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Modeling of a discharging cavity in a dielectric material exposed to high electric fields
KTH, Skolan för elektro- och systemteknik (EES).
KTH, Skolan för elektro- och systemteknik (EES).ORCID-id: 0000-0002-4864-234X
2005 (Engelska)Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

Partial discharges are localized electric discharges that do not bridge the electrodes. For high voltage components measurements of partial discharges arecommonly used to diagnose the condition of the insulationsystem. Traditionally partial discharges are measuredat a single frequency of the applied voltage. Howeverthe rather newly developed technique of VariableFrequency Phase Resolved Partial Discharge Analysis(VF-PRPDA) makes it possible to measure partial dischargesat variable frequency of the applied voltage. Thebenefit of varying the frequency is that more informationabout the state of the insulation system is obtainedthan from measurements at a single frequency. This paperpresents a model of partial discharges in a cavity atvariable applied frequency. The aim of the model is to increasethe physical understanding of how the frequencyof the applied voltage affects the partial discharges in thecavity. This paper studies the influence from the statisticaltime lag on the frequency dependent discharge sequenceand results from simulations are compared withmeasurement data. The model is a 2D time dependent FEMLAB model in PDE mode which is handled from aMATLAB script.

Ort, förlag, år, upplaga, sidor
2005.
Nyckelord [en]
Insulation diagnostics, partial discharges, variable applied frequency
Nationell ämneskategori
Den kondenserade materiens fysik
Identifikatorer
URN: urn:nbn:se:kth:diva-8508OAI: oai:DiVA.org:kth-8508DiVA, id: diva2:13852
Konferens
FEMLAB Conference, Stockholm, Sweden, October 2005
Anmärkning
QC 20101129Tillgänglig från: 2005-11-08 Skapad: 2005-11-08 Senast uppdaterad: 2024-01-12Bibliografiskt granskad
Ingår i avhandling
1. Partial discharges in cylindrical cavities at variable frequency of the applied voltage
Öppna denna publikation i ny flik eller fönster >>Partial discharges in cylindrical cavities at variable frequency of the applied voltage
2005 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Measurements of partial discharges are commonly used to diagnose the insulation system in high voltage components. Traditionally a single xed frequency of the applied voltage is used for such measurements as in the Phase Resolved Partial Discharge Analysis (PRPDA) technique. With the Variable Frequency Phase Resolved Partial Discharge Analysis (VF-PRPDA) technique the frequency of the applied voltage is instead variable. This technique provides more information about the condition of the insulation than the PRPDA technique. To extract the extra information a physical understanding of the frequency dependence of partial discharges is necessary.

In this thesis partial discharges in cylindrical cavities in polycarbonate are measured using the VF-PRPDA technique in the frequency range 10 mHz { 100 Hz. It is studied how the cavity diameter and height inuence the frequency dependence of partial discharges. Insulated cavities are compared with cavities bounded by an electrode. It is shown that from measurements at variable applied frequency it is possible to distinguish between cavities of di erent dimensions and between insulated and metal bounded cavities.

A two-dimensional eld model of partial discharges in a cylindrical cavity is developed. The sequence of discharges in the cavity is simulated by use of the eld computation program FEMLABR. Discharges are modeled with a voltage and current dependent streamer conductivity and are simulated dynamically to obtain charge and current consistency. It is shown that the frequency dependence of partial discharges is signi - cantly inuenced by the statistical time lag and by the two dielectric time constants related to charge movements on the cavity surface and in the bulk insulation. Simulation results are used to interpret the frequency dependent partial discharge activity in a cylindrical cavity.

Ort, förlag, år, upplaga, sidor
Stockholm: KTH, 2005. s. viii, 49
Serie
Trita-ETS, ISSN 1650-674X ; 2005:13
Nationell ämneskategori
Den kondenserade materiens fysik
Identifikatorer
urn:nbn:se:kth:diva-477 (URN)91-7178-169-2 (ISBN)
Presentation
2005-11-11, Sal H1, Teknikringen 33, Stockholm, 13:00
Opponent
Handledare
Anmärkning
QC 20101129Tillgänglig från: 2005-11-08 Skapad: 2005-11-08 Senast uppdaterad: 2022-06-26Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Comsol

Sök vidare i DiVA

Av författaren/redaktören
Forssén, CeciliaEdin, Hans
Av organisationen
Skolan för elektro- och systemteknik (EES)
Den kondenserade materiens fysik

Sök vidare utanför DiVA

GoogleGoogle Scholar

urn-nbn

Altmetricpoäng

urn-nbn
Totalt: 257 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf