Article,
A STATISTICAL APPROACH FOR INSULATOR DESIGN IN POLLUTED AREAS
(1983)
Abstract
The paper describes the statistical approach used
by ENEL in the design of insulators to be used in polluted
areas. This approach includes determination, on
a statistical basis, of the type and level of the pollution
of the site, choice of the artificial laboratory
test method suitable for that site, determination of
the withstand severity of an insulator set which assures
a pre-established risk of failure of the line or
substation to be designed, and eventually, choice of
the insulator set (insulator type, insulator set length
and arrangement) on the basis of the results of labor~
tory tests. In particular, the problem of determining
site severity is amply discussed in the paper and the
relevant method developed by ENEL, based on surface
conductance measurements on sample insulators, is fully
described. The results of systematic long-term recording
performed by this method in several localities
in Italy are reported on and analyzed. Examples of application
of the statistical approach, using these results,
are given and the problem of standardization of
insulators for polluted areas is discussed.
