IEEE Transactions on Dielectrics and Electrical Insulation
Vol. 17, No. 2; April 2010
1070-9878/10/$25.00 © 2010 IEEE
Analysis of Temperature Profiles and Protective
Mechanism against Dry-band Arcing
in Silicone Rubber Nanocomposites
, Shesha Jayaram
, Edward A. Cherney
Department of Electrical and Computer Engineering
University of Waterloo, 200 University Ave. West
Waterloo, Ontario, N2L 3G1, Canada
Instituto de Investigaciones Eléctricas
Reforma 113, Col Palmira
Cuernavaca, Morelos, 62490, México
The paper discusses the mechanism by which nanofillers improve the erosion resistance
of silicone rubber nanocomposites under simulated conditions of dry band arcing.
Various micro-nano composites are studied, including microfiller, nanofiller,
combinations of both, and with a commercial surfactant to improve the dispersion of
the nanofiller. The thermal conductivity of the composites, measured using a standard
method, shows higher thermal conductivity when the nanofiller is well dispersed.
thermal model is developed and solved with finite element method (FEM) to examine
the temperature profile in the modelled nanocomposites under laser heating, which
simulates the hot spot from dry band arcing. The hot spot is compared to the measured
temperature profile by an infrared camera.
SEM, EDAX, and XRD techniques are
used to analyze the thermally decomposed silicone residue after laser heating to
elucidate the protective mechanism in the silicone rubber nanocomposites.
, nanofiller, microfiller, erosion resistance,
thermal conductivity, silicone rubber, outdoor insulation.
addition of micron-sized fillers to silicone elastomers has
been well investigated, and it has been shown that micron size
fillers improve the thermal conductivity (TC) of the resulting
composites, thereby increasing the resistance to erosion due to
dry band arcing .
Meyer et al  demonstrated a good
correlation between the thermal conductivity of the composites
and their resistance to erosion by dry band arcing in an inclined
plane test and by heat ablation with infrared laser.
In this work, the reinforcement of a silicone rubber matrix was
successfully accomplished with a mixture of a type of micro
silica and nano fumed silica, and with a surfactant to improve the
dispersion of the nanofiller.
Standard test methods of salt fog
and inclined plane and a non-standard laser ablation test were
used to evaluate the performance of the micro-nano composites.
It was previously shown that when nanofillers are well dispersed,
the composites show improved resistance to erosion by dry band
Rätzke et al  showed a near linear increase of
thermal conductivity with nanofiller concentration in silicone
Although there are theoretical, semi-theoretical, and