Title :
Effect of humidity on the high voltage characteristics of epoxy/glass insulation
Author :
Hong, T.P. ; Lesaint, O. ; Gonon, P. ; Debruyne, H.
Author_Institution :
Lab. d´´Electrostatique et de Materiaux Dielectriques, Univ. of Grenoble, France
Abstract :
This paper describes the effect of water on dielectric properties at high field of composite insulation, based on epoxy reinforced by fibre glass and mica flakes. Samples with controlled water content are prepared by immersion. Breakdown measurements under ac voltage show a marked decrease of breakdown field, when large amounts of water (up to 1.5%) are present in the material. High voltage dielectric spectroscopy measurements were carried out from 0.001 Hz to 1 kHz with various water content and applied fields (up to 5 kV/mm). At low frequency, a very large increase of dielectric losses versus water content, due to the increase of material conductivity is reported. At 50 Hz, tan δ higher than 1% are recorded with water content above 0.5%.
Keywords :
dielectric losses; dielectric materials; electric breakdown; electrical conductivity; epoxy insulation; filled polymers; glass fibre reinforced composites; humidity; materials preparation; mica; water; 0.001 Hz to 1 kHz; Al2O3-K2O-SiO2; H2O; breakdown field measurements; composite insulation; conductivity; dielectric loss tangent; dielectric properties; epoxy reinforced fibre glass; epoxy reinforced mica flakes; epoxy-glass insulation; high voltage dielectric spectroscopy measurements; humidity; immersion process; water content; Breakdown voltage; Conducting materials; Dielectric losses; Dielectric materials; Dielectric measurements; Dielectrics and electrical insulation; Glass; Humidity; Voltage measurement; Water;
Conference_Titel :
Solid Dielectrics, 2004. ICSD 2004. Proceedings of the 2004 IEEE International Conference on
Print_ISBN :
0-7803-8348-6
DOI :
10.1109/ICSD.2004.1350509
