Lord Consulting
Power Industry Asset Management Consultants
Lord Consulting
Power Industry Asset Management Consultants
Home » Technical Papers » TRANSFORMER CONDITION- BASED RANKING
Large power transformers fleet being in service over 25-30 years composes
over
2,000,000 MVA. Transformer manufacturer capacity available allows replacing
only one year
production that was commissioned e.g. in the end of 1970th. A global task
of power industry
would be prolongation of service of huge aged population preventing cascade-mode
failures
among worn out equipment.
The life buoy is so far a poor correlation between
transformer age and end of life.
Typical failure rate of power transformer is around 2%. It means that another
5-6% may be
expected to have a critical condition from the standpoint of short-term
reliability.
Among the aged population only 15-20% are currently suffered from excessive
deterioration and
require special procedures to prevent early end of life. However this fast
deteriorating fleet
without proper actions would grow with years significantly and would really
threaten with fatal
consequences.
The most appropriate life assessment should concentrate on
factors, which directly influence the
life of the transformer. A relative comparison of the transformers is an
alternative to remaining
life determination, which involves many uncertain assumptions1,2,3. Condition –based
ranking
could be a proper solution to select weak members among the transformer
population.
This paper discusses diagnostic methodology that is focused
on classification of transformer
population in terms its reliability and usability on the basis of design
review, operation condition
review and comprehensive oil analysis, which allow effective ranking
of the transformer
population in the shortest time.