Original scientific paper
PERFORMANCE OF PARALLEL SURGE ARRESTERS
A. Haddad
; Cardiff University, UK
H. Griffiths
; Cardiff University, UK
M. Osborne
; National Grid, UK
Abstract
The operation of parallel surge arresters can improve energy absorption capability if the arresters are
similar and are installed close to each other. However, it has been reported that any small difference in
the individual V-I characteristics can lead to unbalance in current sharing. When the arresters are
installed some distance away from each other, travelling wave effects can modify the effectiveness of
parallel arresters for surge overvoltage protection and, in this case, detailed simulations are required to
ascertain the level of protection. Such a situation occurs in practice with large substations or short
underground cable connections. Various studies have shown that a requirement for two-arrester
protection is closely dependent upon the type and length of cable used.
In the case of overhead lines, the distances are much bigger and the main objective of line arresters is
to reduce the flashover rates due to surge overvoltages. This is especially relevant to lines located in
regions of high lightning activity, lines with compact/uprated design where the phase-to-phase and
phase-to-earth air clearances are reduced.
In this paper, we present a study of parallel arresters considering the separation distance and their
application to overhead lines. Various scenarios of overhead line configurations were considered and
the overvoltage levels were calculated for each case. Assessment of flashover performance is also
conducted for a number of conditions. A number of calculation techniques were used and compared.
Keywords
Line arresters; protection distance; backflashover; lightning strikes; transient simulation; EMTP; cable protection; tower surge impedance
Hrčak ID:
198506
URI
Publication date:
20.6.2017.
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