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Document type:
Konferenzbeitrag 
Contribution type:
Textbeitrag / Aufsatz 
Author(s):
Marold, J.; Kindersberger, J. 
Title:
Impulse voltage breakdown properties of electrodes with thick dielectric coatings in SF6 
Chapter contribution:
T9-75 
Abstract:
For improving the electrical strength of gas insulated switchgears (GIS) dielectric coatings can be used. While thin coatings (< 1 mm) are covering the rough surface by a smooth dielectric layer, coatings with a thickness of several millimetres may change the macroscopic electric field distribution significantly. For electrode arrangements with inhomogeneous field distribution the maximal electric field in the gas gap can be reduced by applying thick dielectric coatings. Thus streamer inception occurs at higher applied voltages and the breakdown voltage increases. The performance of thick dielectric coatings is investigated theoretically and experimentally. The theoretically possible improvement was calculated depending on electrode geometry (field utilization factor 0.25 to 0.53), the relative permittivity εr (2 to 5) and the thickness of the coating (3 to 20 mm). The experimental setup consists of a rod-plane electrode arrangement with different rod diameters (4 and 30 mm), coating materials (Al2O3-filled epoxy resin and polyethylene) and coating thicknesses (3and 8 mm). As insulation gas SF6 at 0.4 MPa was used. 
Book / Congress title:
XV. International Symposium on High Voltage Engineering 
Congress (additional information):
Ljubljana, Slovenia, August 27-31, 2007 
Organization:
University of Ljubljana, Elektroinštitut Milan Vidmar 
Year:
2007 
Month:
Aug 
Pages:
Reviewed:
ja 
Language:
en 
TUM Institution:
HSA