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Frankfurt (Germany), 6-9 June 2011
E. Fred Steennison behalf of
E.Fred Steennis – Netherlands – Session 1 – Paper 0875
THE INTRIGUING BEHAVIOUR OVER TIME OF PD'S FROM DEFECTS IN MV
CABLES AND ACCESSORIESLESSONS LEARNED WITH SCG,
an on-line monitoring system
Frankfurt (Germany), 6-9 June 2011
Content
how to measure PD’s on-line in MV cables some results lessons learned – the intruiging behaviour
of PD’s conclusions
Frankfurt (Germany), 6-9 June 2011
Content
how to measure PD’s on-line in MV cables some results lessons learned – the intruiging behaviour
of PD’s conclusions
Frankfurt (Germany), 6-9 June 2011
How to measure PD’s on-line
applied method = SCG SCG means: Smart Cable Guard
CU SIU
up to 8 km
Frankfurt (Germany), 6-9 June 2011
How to measure PD’s on-line
with SCG diagnose cables (≤ 8 km)
data via internet to KEMA server, 1 h updates
customers have accessto their PD plots
KEMA experts recom-mend on action if needed
Frankfurt (Germany), 6-9 June 2011
Content
how to measure PD’s on-line in MV cables some results lessons learned – the intruiging behaviour
of PD’s conclusions
Frankfurt (Germany), 6-9 June 2011
Some results
4 days
PILC of 666 m with water at 396 m
Frankfurt (Germany), 6-9 June 2011
Some results
3 weeks
XLPE cable of 4.3 km with joint at 1678 m
Frankfurt (Germany), 6-9 June 2011
Some results
> 4 weeks
XLPE cable of 7 km with various weak spots
Frankfurt (Germany), 6-9 June 2011
Some results
3 months
PILC of 2.2 km with liquid filled joint at 1794 m
top view
Frankfurt (Germany), 6-9 June 2011
Content
how to measure PD’s on-line in MV cables some results lessons learned – the intruiging behaviour
of PD’s conclusions
Frankfurt (Germany), 6-9 June 2011
Lessons learned – PD’s are intruiging
How effective is SCG?
4 years SCG 158 km cable monitored
41 defects found in 7 cases (17 %) : no PD at all in 34 cases (83 %) : clear PD activity and
time to act
SCG is effective in warning for upcoming failures
Frankfurt (Germany), 6-9 June 2011
Lessons learned – PD’s are intruiging
SCG . . . . how much time for repair?
Frankfurt (Germany), 6-9 June 2011
Lessons learned – PD’s are intruiging
SCG . . . . how much time for repair?
water in PILC joints with hot conductor screen interruption in XLPE liquid filled joints in PILC
Frankfurt (Germany), 6-9 June 2011
Lessons learned – PD’s are intruiging
SCG . . . . how much time for repair?
water in PILC: days *)
joints with hot conductor screen interruption in XLPE liquid filled joints in PILC
*) between start of heavy PD activity and failure
Frankfurt (Germany), 6-9 June 2011
Lessons learned – PD’s are intruiging
SCG . . . . how much time for repair?
water in PILC: days *)
joints with hot conductor: days *)
screen interruption in XLPE liquid filled joints in PILC
*) between start of heavy PD activity and failure
Frankfurt (Germany), 6-9 June 2011
Lessons learned – PD’s are intruiging
SCG . . . . how much time for repair?
water in PILC: days *)
joints with hot conductor: days *)
screen interruption in XLPE: weeks *)
liquid filled joints in PILC
*) between start of heavy PD activity and failure
Frankfurt (Germany), 6-9 June 2011
Lessons learned – PD’s are intruiging
SCG . . . . how much time for repair?
water in PILC: days *)
joints with hot conductor: days *)
screen interruption in XLPE: weeks *)
liquid filled joints in PILC: months - years *)
*) between start of heavy PD activity and failure
Frankfurt (Germany), 6-9 June 2011
Content
how to measure PD’s on-line in MV cables some results lessons learned – the intruiging behaviour
of PD’s conclusions
Frankfurt (Germany), 6-9 June 2011
Conclusions
SCG can diagnose PILC, XLPE or mix up to 8 km, with 1 % length accuracy exp. so far: 4 years; 158 km monitored effective to see defects on time: 83 % ! PD’s from many types of defects only visible
for a few days before the failure, in others cases there is (much) more time SCG most effective if monitoring over longer time
Frankfurt (Germany), 6-9 June 2011
THANK YOU FOR YOU ATTENTION