Decision-making process for substation renovation …ewh.ieee.org/cmte/substations/scm0/Kansas...
Transcript of Decision-making process for substation renovation …ewh.ieee.org/cmte/substations/scm0/Kansas...
RWE Transportnetz Strom 08-2008 PAGE 1
Decision-making process for substation renovation and equipment
end of life assessment
C. Neumann (Germany)
2009 IEEE Substations Committee Meeting, Kansas City
RWE Transportnetz Strom 04.2009 PAGE 2
Decision-making process for substation renovation and equipment end of life assessment
1.Introduction (German EHV grid)
2.Basic methodology
3.Ascertainment of actual condition
4.Determination of other c - parameters
5.Assessment of end of service life
6.Combination of parameters for decision making
7.Conclusion
RWE Transportnetz Strom 04.2009 PAGE 3
Introduction
Fundamental changes in the regulatory framework of the electricity market in the last decade
Intensified efforts of the grid operators for an optimized utilization of their networks with respect to technical and economical aspects
At the same time the grid operators have to assure a sufficient power quality & reliability
Substations are the nodes of the grid substantially affecting the reliability & availability of the grid in total
Substations represent an essential part of the grid assets
Of particular interest with regard to optimization of the grid costs, i. e. investments & operational expenditure – CAPEX & OPEX
⇒ Methodology and decision making process for substation renovation and equipment end of life assessment
RWE Transportnetz Strom 04.2009 PAGE 4
RWE
EON
VET
EnBW
13193038Share load [%]**
1,9366,7005,4005,200Network length 380 kV [km]
1,7212,8655,3006,100Network length220 kV [km]
76k.A.138175Annual transmission [TWh]
34.6 109.0139.473.1Served area [1000 km²]*
EnBWVETE.ONRWE
* in Germany** Renewable Energy Act load compensation 2005
German EHV grid Operational areas of German Transmission System Operators
RWE Transportnetz Strom 04.2009 PAGE 5
RWE
EON
VET
EnBW
RWE
220 kV transmission lines
380 kV transmission lines
German EHV grid Operational areas of German Transmission System Operators
RWE Transportnetz Strom 04.2009 PAGE 6
RWE
220 kV transmission lines
380 kV transmission lines
90,100 MVA
121110 kV substations
145220 kV transformer
235380 kV transformer
110220 kV substations
62380 kV substations
6,100 km220 kV circuits
5,200 km380 kV circuits
German EHV grid Operational areas of German Transmission System Operators
RWE Transportnetz Strom 04.2009 PAGE 7
Information for decision making process
AM ⇔ qualified information of the system and the equipment installed for the decision making process.
In case of larger population difficult to provide key information manually; therefore reasonable
– application of data based systems
– development of algorithms
Algorithms and method for – determining near-term action and annual business planning
– forecasting the technical and financial effect due to system ageing
Approach based on condition and importance
RWE Transportnetz Strom 04.2009 PAGE 8
Assessment of condition and importance parameters (1)
Assessment of condition parameters
1. Equipment level regarding equipment specific condition parameters, assessment by school marks
static condition quantities: technology, type related service experience (e. g. after sales service quality, maintenance costs), individual failure rates
dynamic condition quantities: age of equipment, individual condition ascertained by inspection and condition checks, interval to next planned maintenance activity
2. Equipment condition parameters accumulated on bay level, weighted according the value of different equipment
3. Assessment on station level → bay condition parameters and on system level → station condition parameters, weighted average mean value
RWE Transportnetz Strom 04.2009 PAGE 9
Assessment of condition parameters on different levels
Subst. A..Z
bay 1
Subst. A Subst. B
circuit breaker disconn. arresterprotect.
transf.
inst. transf.
infrastruct.UPSsubst. contr.bay 2
infrastructureEquimentlevel
Baylevel
Substationlevel
Systemlevel
Condition assessment
Condition parameters
staticquantities
dynamicquantities
RWE Transportnetz Strom 04.2009 PAGE 10
Assessment of condition and importance parameters (2)
Assessment of importance parameters
– Reliability analysis of the different substations
– Derived from short circuit power of the station in question
weighted by a factor reflecting the relevance of the station in the system
Condition and importance parameters normalised to 100
For reliability analysis failure rates to be
regarded. However, failure rates still considered with
condition parameters
RWE Transportnetz Strom 04.2009 PAGE 11
replacement necessary
need for action to be checked
maintenance accor-ding to strategy
0
10
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40
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70
80
90
100
0 10 20 30 40 50 60 70 80 90 100small <<< importance >>> high
good
<<<
con
ditio
n>>
> ba
d
380 kV220 kV110 kV
Condition and importance on equipment level Example: Circuit breakers
RWE Transportnetz Strom 04.2009 PAGE 12
0
20
40
60
80
30 40 50 60 70 80importance
cond
ition
C totC priC secC pri >50C sec >50
Condition and importance parameters of a population of 380 kV stations
BC
A
RWE Transportnetz Strom 04.2009 PAGE 14
0
10
20
30
40
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60
401 402 403 404 407 409 410 411
bay
cond
ition
0
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50
60
401 402 403 404 407 409 410 411
bay
cond
ition
Condition on station level and bay level – condition above 50 –
0
20
40
60
80
100
TE1 TE1 TE1 LS WI WU TD2 ATD
equipmentco
nditi
on
RWE Transportnetz Strom 04.2009 PAGE 15
Decision-making process for substation renovation and equipment end of life assessment
1. Introduction
2. Basic methodology
3. Ascertainment of actual condition
4. Determination of other c - parameters
5. Assessment of end of service life
6. Combination of parameters for decision making
7. Conclusion
RWE Transportnetz Strom 08-2008 PAGE 16
Qualified assessment of actual condition of switching equipment
Qualified condition assessment needs knowledge of the equipment under consideration and the physical background ⇒ experienced and highly skilled personnel.
In case of a large amount of different pieces of equipment and of different types ⇒ high expenditure for training of specialised personnel
⇒ New approach: Application of an “automated, user instructed and data based inspection and diagnosis system” (ADS)
ADS system in use for HV CBs since several years, for DSs under development
RWE Transportnetz Strom 08-2008 PAGE 17
Basic design of “ADS“ system(automated, user instructed and data based inspection and diagnosis)
SF6-Check
Contact travel
Contact resistancestatic & dynamic
diagnosis boxprocess controldata acquisition
data transfer
diagnosis plugcontrol & supervision ofswitching process & driveUser assistance
Maintenance expert may control and supervise the process by remote access UMTS
Im
Um 1), 2), 3) adaptive sensors
1)
3)
2)
RWE Transportnetz Strom 08-2008 PAGE 18
ADS Features
Diagnostic box → four inputs to record different diagnostic quantities
Sequence of the inspection process is automated:
After input of the general data of the breaker to be inspected →maintenance personnel instructed what actions are to be done
All quantities are measured & analysed automatically, all results are stored in a data base
⇒ Reliable, objective & qualified assessment of the actual condition of the equipment under consideration
Depending on the measuring results and the condition check →information, if and what corrective measures have to be taken.
RWE Transportnetz Strom 08-2008 PAGE 19
Results of ADS diagnosis on a 245 kV CB with two interrupter units
20
40
60
80
100
130
20
40
60
80
100
130
24
6810
12
1416
20[mΩ]
24
6810
12
1416
20[mΩ
0 00 10 20 30 40 50 60 70 80ms
0 00 10 20 30 40 50 60 70 80ms
tripping coil current
0.0
0.4
0.8
1.2
1.6
2.0[A] [mm]
switching off process
resistanceunit 1 & 2
0.0
0.4
0.8
1.2
1.6
2.0[A]
0.0
0.4
0.8
1.2
1.6
2.0[A]
contact travel
20 25 30 3520 25 30 35
[mm]
75 µΩ
RWE Transportnetz Strom 08-2008 PAGE 20
Data recorded and analysed by a single shot
The following data can be recorded and analysed by a single shot:
Static and dynamic contact resistance
Operating (making or breaking) time of the main and the auxiliary contacts
Contact travel, i. e. velocity and damping
Current and time characteristic of the tripping coil
In case of an hydraulic drive pressure drop of the hydraulic pressure
All measured results are recorded and analyzed automatically andafterwards stored in a data base.
RWE Transportnetz Strom 04.2009 PAGE 21
1. Introduction
2. Basic methodology
3. Ascertainment of actual condition
4. Determination of other c – parameters
Maintenance,
after sales service
5. Assessment of end of service life
6. Combination of parameters for decision making
7. Conclusion
Decision-making process for substation renovation and equipment end of life assessment
RWE Transportnetz Strom 04.2009 PAGE 22
Average overall maintenance costs of 420 kV CBs per CB-year
0
0,2
0,4
0,6
0,8
1
1,2
1,4
1,6major eventminor event
visual inspectionspecial measure
planed maint. condition acquisition
Ave
rage
over
allm
a int
e nan
cec o
stpe
rCB
-yea
r (in
%o f
new
CB
cost
)
A80
s
B80
s
C63
s
D63
s
E63
s
F63s
G63
s
H63
s
I63o
RWE Transportnetz Strom 04.2009 PAGE 23
Assessment of after sales service quality (CBs)
Man
pow
er fo
r in
stal
latio
n
Inst
alla
tion
time
feas
ibilit
y of
CB
reus
e
Feed
back
with
m
anuf
actu
rer
Stuf
f ava
ilabi
lity
for f
ailu
re re
mov
al
Asse
mbl
y tim
e in
cas
e of
failu
re
Avai
labi
lity
of
spar
e pa
rts
Stuf
f ava
ilabi
lity
for m
aint
enan
ce
Qua
lity
of
mai
nten
ance
C
ost o
f mai
nten
e-
nanc
e pa
ckag
e Ti
me
of u
nava
ila-
bilit
y du
ring
mai
nten
ance
A
sses
smen
t re
sults
Weight [%] 1.8 8.0 8.0 15.6 8.0 11.6 13.5 5.5 9.8 15.9 3.3 100 Range 1-6 1-6 1-6 1-6 1-6 1-6 1-6 1-6 1-6 1-6 1-6 0-100
Type A80s 3 5 1 2 1 3 1 1 1 3 3 21.6Type B80s 5 5 6 5 5 5 5 5 5 4 5 78.6Type C63s 2 2 1 2 1 2 1 1 1 2 2 10.8Type D63s 5 5 6 2 1 3 1 1 1 3 3 30.6Type E63s 3 5 1 3 3 2 2 3 3 2 2 31.7Type F63s 3 5 1 5 5 2 2 3 5 1 1 42.5Type G63s 5 5 1 5 5 2 2 3 5 1 1 43.2Type H63s 3 5 1 5 5 3 3 3 5 3 4 53.8Type I63o 5 5 6 5 5 5 3 3 5 6 6 76.9
Weighting by a decision matrix
Best service 0Worst service 100
RWE Transportnetz Strom 04.2009 PAGE 24
1. Introduction
2. Basic methodology
3. Ascertainment of actual condition
4. Determination of other c - parameters
5. Assessment of end of service life
6. Combination of parameters for decision making
7. Conclusion
Decision-making process for substation renovation and equipment end of life assessment
RWE Transportnetz Strom 04.2009 PAGE 25
Average failure rates of 420 kV CBs
0
5
10
15
20
25
30
35
40
A80s
B80 s
C6 3
s
D6 3
s
E63 s
F63s
G6 3
s
H6 3
s
I63o
Av e
rage
f ailu
rera
tepe
r100
CB
- yea
r s
RWE Transportnetz Strom 04.2009 PAGE 26
Ageing given by related failure frequency (RFF)
Confidence (98%)Failure event years of service
Example of a certain 420 kV CB type
0102030405060708090
100
0 4 8 12 16 20 24years of service
at failure occurrence
RFF
[%]
0
20
40
60
80
100
120
year
s of
ser
vice
Typical ageing process
– Linear loss of basic substance
– Exponentially increasing related failure frequency
– Worse service experience for older equipment
RFF: Failures per year related to 100 CB years [%]
RWE Transportnetz Strom 04.2009 PAGE 27
Related failure Frequency (RFF) of 420 kV CBs
Failure Frequency (RFF) of 420 kV circuit breakers with 95% confidence interval
RFF
[ % ]/
0
10
20
30
40
50
60
70
80
90
100
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32Age (years)
34 36 38 40
Confidenceinterval
RFF (minor)
RFF (major)
Lin. Regression of RFF (major)
Exp. Regression of RFF (minor)
Exp. Regression of RFF (all CBs)
0
10
20
30
40
50
60
70
80
90
100
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40Age (years)
Confidenceinterval
RFF (minor)RFF (major)
Lin. Regression of RFF (major)
Lin. Regression of RFF (minor)
Exp. Regression of RFF (all CBs)
RF F
[ % ]/
RWE Transportnetz Strom 04.2009 PAGE 28
0
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180
200
0 5 10 15 20 25 30 35 40 45 50 55Service time [a]
utili
zatio
n fa
ctor
[%] *
)
End of life prognosis due to knowledge of the basic ageing process
after 20 a
*) utilization factor => expected life related to nominal service life
end of servicelive earlier
end of servicelive later
after 40 a
CBs
⇒ In case of accelerated ageing renovation is brought forward, in case of decelerated postponed
RWE Transportnetz Strom 04.2009 PAGE 29
0
20
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60
80
100
120
140
160
180
200
0 5 10 15 20 25 30 35 40 45 50 55Service time [a]
utili
zatio
n fa
ctor
[%] *
)
End of life prognosis due to knowledge of the basic ageing process
after 20 a
*) utilization factor => expected life related to nominal service life
after 40 a
CBs
DSsarresters
RWE Transportnetz Strom 04.2009 PAGE 31
End of service life assessment of 380 kV substations*(equipment with impermissible utilization factor will be exchanged)
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Zense
Witte
Weste
Weiße
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Siers
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Sankt
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Romme
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Polsu
Paffe
OpladOhlig Oberz
Nordl
Niede
Niede
Nehde
Mitte
Meppe
Menge
Meiti
Lippb
LindeLimbu
Liess
Leupo
Kusen
Krupp
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KobleKnaps
Karna
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Hohen
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Dahle
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Mitte
Nehde
Niede
Niede
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Oberz
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Oplad
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Polsu
Rath
Romme
Rosen
Roxel
Sankt
SechtSiers
Tieng
Uchte
Uentr
Unna
Urber
Utfor
Verla
Vöhri
Walsu
Wehre
Weiße
Weste
Witte
Zense
Zukun
ZukunZense
Witte
Weste
Weiße
Wehre
WalsuVöhri
Verla
Utfor Urber
Unna
Uentr
Uchte
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Secht
SanktRoxel
RosenRomme
Rath
Polsu
Paffe
Oplad
Ohlig
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Nordl
Niede
NiedeNehde
Mitte
Meppe
Menge
Meiti
LippbLindeLimbu
Liess
Leupo
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Krupp
Krift Koble
Knaps
Karna
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Hohen
Hatti
Hanek
Halfe
Gunde
GronaGerst
EnnigEiber
Detti DauerDahle
Büsch
BürstBisch
Arpe
0
10
20
30
40
50
60
70
80
90
100
0 10 20 30 40 50 60 70 80 90 100small<<< importance >>> high
smal
l <<<
>>>
high
actual + 10 a+ 5 a + 20 a
utili
zatio
n fa
ctor
[%] *
)
RWE Transportnetz Strom 04.2009 PAGE 32
Conclusion
For support of the decision making process for substation renovation the asset management needs simple, but technically justified and effective method for assessment
–of actual conditions of the equipment
–end of equipment life
Methods and algorithms described provide qualified information
– for determining near-term action and annual business planning
–also for forecasting the technical and financial effect due to system ageing.