Transcript Diapositive 1

N° EC15
8
8.10 SECONDS
WILL YOUR CABLE REALLY LAST
Patricia Boulanger, John White
?
RELIABILITY
STATISTICAL APPROACH
Long term testing and ageing are of
paramount importance in a wide range
of industries to establish reliability.
By putting a product under stress above
its normal service level, failure modes
and service life reliability can be
determined.
FAILURE SITE ANALYSES
All breakdown sites must be thoroughly
inspected in order to identify the root
cause. To be able to carry out such an in
depth analysis, a wide range of highly
specialized equipment needs to be
used.
speeds,
copper conductor
substrates,
… over 600 samples tested over several
years.
This series of testing has helped us establish a
rigorous protocol to guarantee system
reliability over the required 8.108 seconds
(25 years), with a high level of confidence.
ELECTRICAL TESTING
Alcatel-Lucent Submarine Networks uses
8 different DC ageing platforms from
50kV up to 400kV.
Safety is paramount in the potentially
dangerous conditions of electrical testing.
Operators are qualified, certified, and fully
equipped with the necessary safety
equipment.
Cable samples from different origins
have been tested:
• To ramp-to-failure, using a standardized
voltage increase and stabilization
• Ageing at 190kV
• Ageing at 160kV
• Ageing at 140kV
• Ageing at 120kV
• Ageing at a voltage close to 50kV so as to
be nearer to the service voltage and with a
reversal of polarity. All of this gives the
Weibull distribution of breakdown voltages
and times from which system reliability
can be calculated.