Transient Fault 132 kv single circut

[KMS3330]

hi there,
this year,we face nine transient fault on 132kv single circut and there is no indiction!nothing
i need your help
informations on these problem:
1-it always happens mid night and early morning
2-weather is dry
3-there is auto reclosuer
4-insulations are good ,we did tests and results were ok(dust and flashover on them)
5-old lines: 70km and 90km
6-Distance relay((Static relay (PDS)

 

[7anoter4]

In My opinion, it could be birds or intempestive protection action.

 

[Bung]

Do you have any more information:
-phase fault or ground fault? or a mixture?
-any fog, salt fog, recent high winds?
-is protection duplicated? If so, do both operate?
are the VT circuits ok?
has this just started tohappen, or is it an on-going problem?
if it is recent, does it coincide with changes on the system or in the substation wiring?


Bung
Life is non-linear...

 

[KMS3330]

hi 7anoter4
it was our opinion but its wrong.... thx alot

hi Bung
more information:
-ground fault only
-Distance and OVERVOLTAGE(ONLY DISTANCE operates)
-are the VT circuits ok? i'm not sure
-same problems since 2000
-only this year from 1/1/2012 to 20/03/2012 3 Transient Faults

 

[7anoter4]

Have you results of Fault Recorder or Sequence Event Recorder in order to know which control ordered the breaker trip?
Did the Substation crew manual switch manoeuvres to connect or disconnect line ?
If it is at night could be a result of a human wrong manoeuvre.

 

[odlanor]

2-weather is dry

4-insulations are good ,we did tests and results were ok(dust and flashover on them)
5-old lines: 70km and 90km

-same problems since 2000
-only this year from 1/1/2012 to 20/03/2012 3 Transient Faults
-------------------------------------
electrical discharge strike on 90km old transmission line in a region with bad weather , where insulations have changed since year 2000,, and very FAR from subestation where weather is DRY
, but occurs results shot reclosure on the line.