Conference,
COMPOSITE INSULATORS Willi SILICONE RUBBER HOUSING FOR USE IN THE 230 KV OVERHEAD LINE BETANIA- MIROLINDO IN INTERCONEXION ELECTRICA S.A. (ISA), COLOMBlA
(1997)
Abstract
1be increased use of composite insulators in HV
transmission lines is based on the advantages of these
insulators and the results of long term experience gained
with particular insulntor designs. Silicone rubber and EP
rubber arc !he dominant housing materials for composite
insulnt<irs. Silicone rubber is considered to be the best
material for HV outdoor insulation, proven by service
experience. Due to a l:ick oi adcqUE.te accelerating test
methods the selection of composite insulnlors for the
application at a particular site can only rely on long term
~cn·ice experience under operational conditions obtained
from other sites. 1bis experience revealed the superiority of
silicone ruhber compared lo EP rubber and conventional
insulators and can be traced back t.O an int.craction of the
silicone rubber with the pollution particles, not known from
other materill!s. The hydrophobicity transfer prevents
silicone rubber insulators from electrical degradation. Thus,
ISA decided to specify composite silicone insulators of a
particular design for the 230 kV line Betania - M.irolindo.
The line runs through a mountain area up to 1 200 m. For
!his line composite silicone rubber insulators olfcr besides
of technical advantages also economical benefits.
Apart from the design ISA specified test sequences
described in !EC I 109. The acceptance test report ·was
demanded before supply and taking Oér the insulators. TI1e
tests were carried out in the test facilities of the
manufacturer and comprised electrical and mechanical
testing as well. All tests were passed by the insulators and
insulator strings respective! y.
