condition health indices and probabiltiy of failure
DESCRIPTION
Transformer condition health indices, probability of failures, maintenance and replacement cyclesTRANSCRIPT
Condition Health Indices and Probabilities of Failure
Thor HjartarsonPrincipal Engineer, Asset Management
5th Annual Weidmann-ACTI Technical ConferenceAlbuquerque, New Mexico13-15 Nov. 2006
Kinectrics Inc.• Formerly the R&D wing of Ontario Hydro, Canada’s largest electrical
utility, for 90 years.• 1999 province of Ontario started deregulation process of industry.• Established as a separate company on 8/2/00.
Comprehensive Solutions in:
üGenerationüTransmission and Distribution üEnvironmental Solutions
Kinectrics’ Businesses
Transmission Systems
Small Hydro
Electrical Testing
North American Energy Companies
Over 250 Large Utilities
North American Energy UsersOver 1000 Large Organizations
North American OEMs, Engineering Services Companies
Over 50 Large Companies
Global Energy Companies & OEMsOver 20 Large Organizations
Kinectrics’ Markets
• Asset Management• Insulation Diagnostics & Condition
Assessment • Power System Performance• Power Quality Services• Protective Relaying & Telecommunications• Electromagnetic Compatibility, Radio & TV
Interference• Fiber Optic Cable & Hardware Testing• Design & Maintenance Optimization• Safety Equipment Insulation Testing• Electrical Systems Testing• Products
Electrical Systems Capability
High Voltage and High Current Testing
• Conduct testing for certification, product development, and failure analysis
• Identify if products operate to standard/non-standard requirements
Asset ManagementAsset ManagementAsset management is simply the optimal way of managing assets to achieve desired outcome
and is defined as:
Systematic and coordinated activities and practices through which an organization optimally manages its assets, and their associated performance, risks and expenditures over their life cycle for the purpose
of achieving its organizational strategic plan
Holistic
Systematic
Systemic
Risk Based
Optimal
Sustainable
AM Approach
The successful implementation of asset management requires a multi-dimensional approach – BSI Standard PAS - 55
Health Indexing of Operational AssetsHealth Indexing of Operational Assets
– Establishes objective, verifiable, and measurable condition criteria other than age
– Provides data useful for trending asset condition
– Quantifies condition of all types of operational assets
– Describes single assets or populations of widely-distributed assets
How Health Indexing has EvolvedHow Health Indexing has Evolved
Internationally (examples)• United Utilities, UK• ESB, Ireland• Central Networks , UK• Scottish and Southern Energy, UK• EDF Energy, UK• North Ireland Electricity• Western Power Distribution, UK• Hydro OGK, Russia• Yakutskenergo, Russia
North America (examples)• Exelon• Idaho Power• Powerstream, Ontario• Toronto Hydro• Hydro One Inc, Ontario • British Columbia Transmission Company• BC Hydro• Hydro Ottawa, Ontario• New York Power Authority• Yukon Energy Corporation• Great Lakes Power, Ontario• Newfoundland and Labrador Hydro• ENMAX Corporation, Alberta• Pacificorp, Oregon, USA• CEATI, Utility Research Group
Since Original Health Index Project with Hydro One in 2002, over 20 companies have implemented the methodology
About 10 technical papers have been published on the subject and presented at key conferences
Implementation Implementation –– WhereWhere
Number of Companies in Canada, United States, United Kingdom and Ireland that have implemented the
Health Index Methodology
13
9
20
35
0
5
10
15
20
25
30
35
40
2002 2003 2004 2005 2006
Year
Nu
mb
er o
f Co
mp
anie
s
Health Index Formulation
Corporate Maintenance
Standards
Best Practice Maintenance
Processes
Corporate Internal Knowledge – Key Staff
Health Index Knowledge and
Experience Designated Subject Matter Experts
Determination of Measurable Asset
End-of-Life Criteria
Health Index FormulationHealth Index Formulation
Trans-former
Health Index
1Radiator/Cooling
WeightTransformer Visual Inspection Criteria
2Overall Physical
1Oil Leaks1Conservator1Main Tank/ Controls1Bushing Condition
Frequency Response3
Winding Doble Test4Thermograph2Sound Signature3
3
44
Weight Transformer Testing Analysis Criteria
Standard Oil Test
Furan AnalysisAge Information
DGA Analysis
Transformer Inspections:
Transformer Testing:
1Tank Leaks3Overall Physical
WeightTap Changer Criteria
3DGA, Metal Content
1Control & Mechanism1Gaskets/Seals1Tank Condition
Tap Changer Criteria:
Transformer Health Index FormulationTransformer Health Index Formulation
Example: Subject to Discussion with Client
Bushings/Support Insulators, cementing or fasteners are broken/damaged beyond repair.
E
Bushings/Support Insulators are broken/damaged, or cementing or fasteners are not secure.
D
Bushings/Support Insulators are not broken, however there are some major chips and cracks. Some evidence of flashover burns or copper splash or copper wash. Cementing and fasteners are secure.
C
Bushings/Support Insulators are not broken, however there are some minor chips and cracks. No flashover burns or copper splash or copper wash. Cementing and fasteners are secure.
B
Bushings/Support Insulators are not broken and are free of chips, radial cracks, flashover burns, copper splash and copper wash. Cementing and fasteners are secure.
A
DescriptionCondition
Rating
Typical Health Index Condition Rating
Asset Evaluations – Health Index
Example of DGA Scoring
Condition Rating
Description
A DGA overall factor is less than 1.2 B DGA overall factor between 1.2 and 1.5 C DGA overall factor is between 1.5 and 2.0 D DGA overall factor is between 2.0 and 3.0 E DGA overall factor is greater than 3.0
Where the DGA overall factor is the weighted average of the following gas scores:
Scores 1 2 3 4 5 6 Weight
H2 <=100 <=200 <=300 <=500 <=700 >700 2 CH4 <=120 <=150 <=200 <=400 <=600 >600 3
C2H6 <=50 <=100 <=150 <=250 <=500 >500 3 C2H4 <=65 <=100 <=150 <=250 <=500 >500 3 C2H2 <=3 <=10 <=50 <=100 <=200 >200 5 CO <=700 <=800 <=900 <=1100 <=1300 >1300 1 CO2 <=3000 <=3500 <=4000 <=4500 <=5000 >5000 1
* See also IEEE standard C57.104-1991 ; IEEE Guide for the Interpretation of Gases Generated in Oil-Immersed Transformers – The above formulation is an advanced development from this standard.
Health Index Results
1 1337
89
169
0
50
100
150
200
Very Poor0 - 30
Poor30 - 50
Fair50 - 70
Good70 - 85
Very Good85 - 100
Health Index Categories
Num
ber
of U
nits
Asset Group
4.2% 11.9%
28.8%54.7%
0.4%
Very Poor Poor Fair Good Very Good
Typical Health Index ResultsTypical Health Index Results
Health Index Condition Life remaining Requirements
85 - 100 Very Good As new Normal maintenance
70 - 85 Good More than 15 years Normal maintenance
50 - 70 Fair 5 to 15 years Increase diagnostic testing, possible remedial work or replacement needed depending on criticality
30 - 50 Poor Less than 5 years Start planning process to replace or rebuild considering risk and consequences of failure
0 - 30 Very Poor At end-of-life Immediately assess risk; replace or rebuild based on assessment
0.0%
20.0%
40.0%
60.0%
80.0%
100.0%
0 10 20 30 40 50 60 70 80
Age (years)
Rat
io o
f Fai
led
(End
-of-
Life
) A
sset
s Mean Life of Asset
0.0%2.0%4.0%6.0%8.0%
10.0%12.0%14.0%16.0%18.0%20.0%
0 10 20 30 40 50 60 70 80
Age (years)
Prob
abili
ty o
f Fai
lure
Typical Asset Life CurvesTypical Asset Life Curves
Based on: • Industry knowledge• Manufacturer Expectations• Benchmark Failure Data• Utility Specific Data
Limitations: • Averages, not asset specific• Often limited failure data• Failure data may be irrelevant• Location, Environment etc.may not be considered
0.0%10.0%20.0%30.0%40.0%50.0%60.0%70.0%80.0%90.0%
100.0%
0 10 20 30 40 50 60 70 80Age (years)
Rat
io o
f Fai
led
(End
-of-
Life
) A
sset
s
Mean Life of Asset
Very Good Good Fair Poor Very Poor
0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
0102030405060708090100
Health Index Score
Prob
abili
ty o
f Fai
lure
Very PoorPoorFairGoodVery Good
From Condition to Probability of FailureFrom Condition to Probability of Failure
Correlating Health Index results to Probability of Failure:• HI Formulation Design• Estimate Effective Age• Estimate Probability of Failure• Adjust with Increasing Data
Furthermore: • Rate of Deterioration• Remaining Life Determinations• Effect of Intervention Options• Asset Class Future Condition Predictions
Bi-Annual Failure Rate versus Condition Category
0%10%20%30%40%50%60%70%80%
100-85 84-70 69-50 49-30 29-0
Condition Category
Bi-A
nn
ual
Fai
lure
Rat
e
Actual Failure Rate
Fitted Curve
Bi-Annual Failure Rate versus Age
0%
1%
2%
3%
4%
5%
6%
0-10 11-20 21-30 31-40 41-50 >50
Age Group
Bi-A
nn
ual
Fai
lure
Rat
e
Actual Failure Rate
Fitted Curve
Experience Experience –– Health Index and Failure RatesHealth Index and Failure Rates
The original Health Index analysis and experience 2-years later
• The transformers found in Fair and Poor condition were closely supervised immediately following the original study
• One-Third (33% - 20 units) of them failed or reached end-of-life in the two year period and had to be replaced – some of the transformers were not old at all
• By planning these replacements instead of waiting for them to fail had significant cost savings and avoided large customer interruptions
06046239
1321
0200400600800100012001400
Very Poor0 - 30
Poor30 - 50
Fair50 - 70
Good70 - 85
Very Good85 - 100
Health Index
Num
ber
of tr
ansf
orm
ers
Maintenance and The Life Curve
What is the Economic Life of an Asset?
• Replacement asset • Existing asset
Program Development – Methodology
Replace when cost of existing asset exceeds cost of new
Optimizing Replacement Timing
Period of Replacement
Total Annualized Cost
1 $507,3962 $263,2313 $190,2004 $165,6705 $167,3596 $189,5977 $230,9888 $291,1469 $369,62810 $465,646
Defining Costs
– Capital and risk costs are expressed on an annualized basis.
– Risk cost is the probability of failure times the consequence cost.
• Probability increases with age• Consequence cost includes outage effects, repair cost,
etc.
Wood Poles
Underground Cables
Forestry
Stations
Metering
Demand Programs
Other
Optimal Multi-Year
Overall Sustain-
mentProgram
Intermediate Programs
List
List
List
List
List
List
List
Asset Demographics
Asset Life Risk Analysis
System Issues
Asset Condition
Condition/Failure Correlation
Consequence Costs
High
Med
Low
Good Fair PoorCondition Index
Co
ns
eq
ue
nc
e
Co
st
Health Index
High
Med
Low
Good Fair PoorCondition Index
Co
ns
eq
ue
nc
e
Co
st
High
Med
Low
Good Fair PoorCondition Index
Co
ns
eq
ue
nc
e
Co
st
Health Index
INCREASING RISK-COST
Corporate Considerations• Corporate Values• Economic/Financial
Constraints• Environmental and Safety• Resource Capabilities• Regulatory Requirements• Superseding Programs• Benchmarking
Asset Criticality
Asset Functionality
The Asset Based ProcessThe Asset Based Process
Circuit Breakers
HIGH 146 12 4
MEDIUM 350 24 8
LOW 150 12 4GOOD / FAIR POOR /
VERY GOOD VERY POORHealth Index
Co
nse
qu
ence
C
ost
s
-
200,000
400,000
600,000
0 15 30 45Low Risk-Cost,Delay Replacement
-
200,000
400,000
600,000
800,000
0 15 30 45
Medium Risk-Cost,Plan Replacement
-
300,000
600,000
900,000
1,200,000
0 15 30 45High Risk-Cost,
Replace Immediately
Risk Matrix ExampleRisk Matrix Example
Example of Risk Matrix
Transformers Risk Matrix
$0 million
$1 million
$2 million
$3 million
$4 million
$5 million
$6 million
$7 million
0% 2% 4% 6% 8% 10% 12% 14%
Near-Term Failure Probability
Con
sequ
ence
Cos
t
Transformer Population
Three-year program
Asset SustainabilityAsset Sustainability
High
Med
Low
Good Fair PoorCondition Index
Co
ns
eq
ue
nc
e
Co
st
Health Index
High
Med
Low
Good Fair PoorCondition Index
Co
ns
eq
ue
nc
e
Co
st
High
Med
Low
Good Fair PoorCondition Index
Co
ns
eq
ue
nc
e
Co
st
Health Index
INCREASING RISK-COST
Asset ConditionHealth Index
Risk MatrixAsset Criticality
Consequence Cost
Age
Failure History
Obsolescence
Outage Safety
ImageEnvironment
Maintenance
Optimized Asset Program
0
510
15
20
2530
3540
45
2006
2008
2010
2012
2014
2016
2018
2020
2022
2024
Year of Spending
$MAsset 5Asset 4Asset 3Asset 2Asset 1
Transformer Replacement/Rewind Program
$0
$200,000
$400,000
$600,000
$800,000
$1,000,000
$1,200,000
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
Year
Cap
ital C
ost
-7-6-5-4
-3-2-101
23456
789
Qu
anti
tyOptimized Cost
Average Cost of Levelized program
Optimized Quantity
Levelized Quantity
Implementation Implementation –– The 9 StepsThe 9 Steps
1. The Company Vision –Understanding the Requirements
Every company is different. Where does the company want to go? What are the main concerns and challenges?
4. Collect the Attainable DataAvailable data collected from company sources and databases
2. Methodology Customization –Company Buy-In
Adjust the methodology to the specific vision and challenges of the company – get agreement on approach
3. Assessment of Information Requirements
Map what type of information is required for successful implementation
5. Devise Methods to Bridge Data GapsBenchmark and industry data; facilitated assessments with company experts, sample surveys.
6. Model According to Methodology DecidedApplication of the methodology. Data and assessments used to produce first set of results -review with company
7. Produce ResultsLong term Asset Management Plan produced, report, presentation of findings.
8. On-Going Process ImplementationPlanning the future – implementing the process so it becomes a part of the operation – projects to improve information.
9. Software Modules/Tools AdaptationEvaluate what tools will be needed and acquire them.
Timeline Months 1 2 3 4 5 6
The Tasks1. , 2. and 3. 4. and 5. 6. and 7. 8. and 9.
What are the Benefits?What are the Benefits?
Increasingly standards on asset management planning have been implemented – the most notable is British Standard PAS 55
4. On-Going Operation and Management• Long term resource needs are known and
potential over-staffing or under-staffing can be addressed in a timely manner
• Gaps are addressed and plans put in place to start collecting information during regular maintenance activities
• Process is kept live and with increasingly better information it will become a vital executive tool.
• E.g. Company that has implemented this process has seen their asset and system needs better identified and been able to prioritize projects and resources resulting in more efficient management and understanding.
3. Performance and Reliability• Asset management plan based on set reliability
targets, and with successful implementation these targets should be reached.
• Drivers for plan based on current and projected condition allowing for timely interventions before failures occur instead of looking solely at past performance statistics.
• E.g. Results for a company showed a number of power transformers in bad condition – half of them were replaced within the next 2-3 years avoiding imminent failures with significant customer interruptions.
2. Costs and Income• More planned and less unplanned costs
resulting in significantly lower overall expenditures.
• When increased expenditures are needed they are foreseen allowing for better defined income requirements.
• Costs are driven by asset needs – not by historical needs or resource availability needs.
• E.g. Company examining their maintenance policies was able to decrease costs by 10% without affecting performance.
1. Defendable Asset Management Plan• Optimized life cycle plan developed based on
the real asset sustainability• This has proven essential for rate application
support• E.g. Results for a company showed that
expenditures needed for an asset group would greatly increase in 5 years – this need was identified in rate application allowing for timely and adequate income adjustments to face these unavoidable costs.
Thor HjartarsonAsset ManagementPhone: 416.207.5944Mobile: 289.242.5454
Russell PenningtonDirector, Business Development
Phone: 704.948.4118Mobile: 704.773.0737
www.kinectrics.com
Thank You!Thank You!