Generating Asset Health Indices which are both …...Definitions (from ISO 55000) Term Working Definition Asset an item, thing or entity which has value or potential value Asset Management

GeneratingAssetHealthIndiceswhicharebothUsefulandAuditable

TonyMcGrail, JayGarnettDobleEngineering

[email protected]@doble.com

MIPSYCON2016

Summary:AssetHealthIndex(AHI)

• AHIisanestimateofagenerallyunknownvariable:theactualtransformerhealth• Estimatingwhat– healthyenoughtodowhat,exactly?• Moredata,shouldbeabetterestimate?

• Theindexshouldbeuseful– whatdoestheletter/numbermean:• Answeraquestion…

• Anindexshouldhaveassociatedaction &timescale• Timescalesshouldcalibrate– beconsistent

• Howtomakeituseful?• Supportdecisions:justifyactionsinanauditablemanner

• Action?• Timescale?• Justification?

• Probability?

• Cost?• Consequence?• Risk?

Estimates…

ForewordIntroduction1) Scope2) NormativeReferences3) Terms&Definitions4) ContextoftheOrganization

4.1)Understandingtheorg&context4.2)Understandingneedsofstakeholders4.3)DeterminingscopeofAMsystem4.4)AMSystem

5) Leadership5.1)Leadership&Commitment5.2)Policy5.3)Organizedroles/responsibilities/authorities

6) Planning6.1)Actionstoaddressrisks/opportunitiesforAMS6.2)AMObjectivesandplanningtoachievethem

What’sinISO55001:AssetManagementStandard?

7) Support7.1) Resources7.2) Competence7.3) Awareness7.4) Communication7.5) Information Requirements7.6) Documented Information

8) Operation8.1) Operational planning & control8.2) Management of change8.3) Outsourcing

9) Performance Evaluation9.1) Monitoring, measurement, analysis & evaluation9.2) Internal audit9.3) Management review

10) Improvement10.1) Nonconformity & corrective action10.2) Preventive action10.3) Continual Improvement

Definitions(fromISO55000)

Term WorkingDefinitionAsset anitem,thingorentitywhichhasvalueorpotentialvalue

AssetManagement Coordinatedactivitiesofanorganization torealizevaluefromassets

AssetPortfolio Assetswithinthescopeofanassetmanagementsystem

AssetSystem Setofassetswhichinteractorareinterrelated

Criticalasset Assethavingthepotentialtosignificantly impactontheachievementoftheorganizationsobjectives

Risk Effectofuncertaintyonobjectives;

Uncertainty Uncertaintyisthestate,evenpartial,ofdeficiencyofinformationrelated to,understandingorknowledgeofanevent,itsconsequence,orlikelihood.

Criticality Notdefined

Impact Notdefined– usedinreferencetocriticalasset

Consequence Notdefined– usedinriskdefinitionandreferstoISOGuide73,3.6.1.3

• Needpopulationstatistics• Identifyfailuremodes:

• Insulationdeterioration?• Mechanicaldamage?• Thermalperformance?

• ROOTCAUSEANALYSIS!• Timescaleforfailuremodetoprogress• Failuremode– parameterswhichcan

indicateanissue• Mitigate:

• Reduceprobabilityofoccurrence• Reduceconsequenceofoccurrence

• AHI:ISO55000section9.1:• Monitor/measure/evaluate/analyze

Whenwillyourassetfail?Whywillitfail?

6

Whichmaintenance,monitoringorassetreplacementtasksarereallyworthwhileandwhen?

Quotes- AssetManagement

“If engineers do not talk the language of business, they do not deserve to be heard.”

CEO of the Institute of Asset Management

“If top management don’t talk the language of risk and criticality – and understand why maintenance can be an investment – they do not deserve to be leaders.”

We need a way to translate between the two groups.Asset management is all about the money, in the same way football is all about the ball.

TranslationEnglish-Welsh

• Agedoesnotnecessarilyimplycondition

Agedassets– butwhichonesneedattention?

Substation Operating Transformers Age ProfileNational Grid - EDO

DxD

TxD

0

5

10

15

20

25

30

35

40

1901 1907 1913 1919 1925 1931 1937 1943 1949 1955 1961 1967 1973 1979 1985 1991 1997 2003 2009

Year

Qua

ntity

0%

20%

40%

60%

80%

100%

Cum

ulat

ive

%

Units without age data 26.83%

Condition alonedoesn’t tellusabout riskIEEEC57.91 LoadingGuide:expectedlifeofatransformer:180,000hours (20.55years)

Waterfall

Intervention:DoubleFeedbackLoops

Target:healthytransformer

Shorttermtestingandmonitoring

Longtermtestingandanalysis

Environmental effects

Environmental effects

Shorttermintervention(innerloop)

Longtermintervention(outerloop)

+/- +/-

Need to identify which is appropriate for a particular unit

DealingwithAnomaly

PlanningIntervention

Collect data: condition, operation, family/design, industry etcAnalyze data: looking for anomaly and outliersID anomaly: based on individual asset data, which may combine condition and operation data or

aggregate data across several assets or asset typesDiagnose: find possible causesPrognosis: what is likely to happen, with what consequences, when?Intervene: replace a failed unit; repair/refurbish a unit that is failing ‘gracefully’; plan longer term

investment; provide assurance via monitoringMonitor: analyze, review , and check interventionIterate: further data collection

IEEE “Data and Decisions” 2011 Smart Grid Conference, Perth, Australia

‘Graceful’and‘RapidOnset’BushingFailures

“Condition Monitoring in theRealWorld”

KenWyper,GraemeMacKay:TransGrid,AustraliaTonyMcGrail:DobleEngineering,USAInternationalConferenceofDobleClients,2013,BostonUSA

Rapid… minutes… ‘less predictable’

Graceful… over months… ‘predictable’

Data…summingtirepressures…

TirePressureDataMining

Mileage Dist MPH Revs MPG Ambient31782 70 72 1350 35 38331776 64 75 2100 20 3831775 63 65 1750 33 3831773 61 65 1800 40 3931772 60 65 1700 30 3831722 10 0 750 0 2131712 0 0 750 0 22

Vecsum3.4643.4643.4643.6064.0002.0001.732

Noisysum3.1433.4233.2243.5394.1772.1121.569

FL FR BL BR34 39 37 3833 39 37 3733 39 37 3733 38 37 3733 37 37 3733 37 35 3533 36 35 35

Data processing removes information

Sum148146146145144140139

FL

FR

BR

BL

Θ

WillanAssetHealthIndexhelp?

• What problem are you trying to solve?

IndexandIndices

• What data do we have? Quite possible to ‘start’ with basic nameplate and DGA data• What scale should we use? What are we scoring?

• If we use 1 – 10, say: 1 is new/good and 10 is ‘about to fail’:– what does 6 mean? – how does 6 compare to 7– is 6 twice as bad as 3? Twice as likely to fail?– How accurate or precise is the number? – What does 3.9 mean? And what if it changes to 4.2????

• Can we relate the health index to a ‘likelihood of failure’?– Only if we have identified the failure modes…

• Key to extracting value: action and timescale• Key to keeping your job: justifiable audit trail

Combine?Calibratetimescales

Code Description

1 transformerisexpected tolastfortheforeseeable future,andatleast15years2 transformerisexpected tolastupto15yearsbutmayneedtobereplaced in5-15years3 transformerisexpected tolastupto5yearsandmayneedtobereplaced in2-5years4 transformerisonactive listforreplacement within2years

Code Description1 Noknownproblems3 Slightlyunusualdissolvedgassignature10 Possiblearcing/sparkingorpartialdischarge fault30 Severearcing/sparkingorpartialdischargefault100 Verysevere arcing/sparkingorpartialdischarge fault,

transformer athighriskoffailure

• 3unitswithsimilarweightedscore• Whichunitneeds ourattention?Which ismosturgent?• Whichunitismostlikelytofail?

Uniformweighting…1good,5bad

Factor ScoreRange Trf1 Trf2 Trf3DGAMainTankScore 1-5 2 1 1DielectricScore 1-5 1 1 1ThermalScore 1-5 2 1 1MechanicalScore 1-5 3 4 1OilScore 1-5 1 1 1DGALTCTankScore 1-5 3 1 5OperationalScore 1-5 2 3 3Design/manufacturerScore 1-5 1 4 1SubjectMatterExpertScore 1-5 3 1 2Sum 9-45 18 17 16NormalizedSum(%) 100 40 37.8 35.6

Logarithmicscaling?1good,100bad

Factor ScoreRange Trf1 Trf2 Trf3DGAMainTankScore 1,3,10,30,100 3 1 1DielectricScore 1,3,10,30,100 1 1 1ThermalScore 1,3,10,30,100 3 1 1MechanicalScore 1,3,10,30,100 10 30 1OilScore 1,3,10,30,100 1 1 1DGALTCTankScore 1,3,10,30,100 10 1 100OperationalScore 1,3,10,30,100 3 10 10Design/manufacturerScore 1,3,10,30,100 1 30 1SubjectMatterExpertScore 1,3,10,30,100 10 1 3Sum 9-900 42 76 119NormalizedSum%) 900 4.7 8.4 13.2

Linear Log0 01 12 33 104 305 100

Scalecalibration

• Sameunits asbefore– nowonlogscales• Whichunitneeds ourattention?Which ismosturgent?• Whichunitismostlikelytofail?

• Aretheyuseful?• Dotheyhelpmakedecisions?• Dotheyprovidejustificationandanaudittrail?

• Modeoffailure• Timetofailure

• Shorttermvlonger term

Aspectsofpracticalsystems

• Reviewavailable dataasaroundtable exercise• Includedesigntype,DGA,offlinetest, localknowledge…

• Scorethemembersofthepopulation• Reviewbased on‘known’failurerates

• Justhowmanycode3andcode4’sshouldtherebe?

DelphicApproach– DGAusedasabase

Code Description

1 transformerisexpected tolastfortheforeseeable future,andatleast15years2 transformerisexpected tolastupto15yearsbutmayneedtobereplaced in5-15years3 transformerisexpected tolastupto5yearsandmayneedtobereplaced in2-5years4 transformerisonactive listforreplacement within2years

At0.5%peryearfailurerate…Code4:about1%ofpopulationCode3:about1.5%ofpopulation

Addmoredataandreviewasdatabecomes available

System:Reviewingaweightingsystem

• Practicalsysteminuseatpresent• Weightedscoresforseveralcomponents• Combinedsuminterpretedasa“ProbabilityofFailure”(PoF)• Datadisplayedonariskchart• Iso-risklinesusedasreference– predeterminedbyutility• Trackvariationinonetransformer– S5 – withvariationinsinglekeyfactor

Reality:Weightedsystem

% Final 25.00 10.00 10.00 10.00 5.00 5.00 5.00 10.00 Sum 100.00Weighting 5 2 2 2 1 1 1 2

SubstationBushing PowerFactor

FQ TransformerPower Factor

Bushing PowerFactor

AgeScore Faults Load Failure

Rate TYPE TYPE LTC

TYPE Bushing AHI Consequence RISK

S1 0 0 0 0 5 0 0 0 3 4 0 21 5 105S2 4 0 0 4 0 0 5 0 0 0 5 53 18 954S3 0 0 0 0 2 0 1 0 0 5 0 23 24 552S4 1 0 0 1 5 0 0 0 0 0 5 32 32 1024S5 0 0 1 0 0 0 0 0 0 0 0 2 12 24S6 5 0 4 5 2 0 0 0 5 5 5 65 4 260S7 4 1 0 4 0 0 5 5 0 0 5 65 39 2558S8 1 0 0 1 0 0 0 5 0 0 0 17 36 611S9 4 1 0 4 2 0 0 5 3 0 0 54 37 2013S10 4 0 0 4 3 0 0 0 3 4 0 47 17 821

Max 5 5 5 5 5 5 5 5 5 5 5 100 100 10000

20.004

S1

S2

S3

S4

S5

S6 S7

S8

S9S10

0

10

20

30

40

50

60

70

80

90

100

1 11 21 31 41 51 61 71 81 91 101

ASsetH

ealth

Inde

x

ConsequenceofFailure

WeightedAHIScores&Risk

Datapoint(AHI,Consequence)

Isorisk lines at:• risk=225• risk=750

S1

S2

S3S4

S5

S6 S7

S8

S9S10

1

10

100

1 10 100

ASsetH

ealth

Inde

x



Variations– Bushinggoestoworstpossiblecondition

S1

S2

S3

S4

S5

S6 S7

S8

S9S10

0

10

20

30

40

50

60

70

80

90

100

1 11 21 31 41 51 61 71 81 91 101

ASsetHealth

Inde

x



S1

S2

S3

S4

S5

S6 S7

S8

S9S10

0

10

20

30

40

50

60

70

80

90

100

1 11 21 31 41 51 61 71 81 91 101

ASsetHealthInde

x



S1

S2

S3S4

S5

S6 S7

S8

S9S10

1

10

100

1 10 100

ASsetHealthInde

x



S1

S2

S3S4

S5

S6 S7

S8

S9S10

1

10

100

1 10 100

ASsetHealthInde

x



Systemisgoodforlongerterminvestment justifications- shorttermoperationalresponse covered‘elsewhere’- modeoffailure,time tofailure…

Methodologywasoriginally developedwithinNational GridUK,andhasbeensincedeveloped byDobleEngineering. Methodology hasbeendeveloped throughalmosttwentyyears’experience.

Methodology hasbeenapplied, inwholeorinpart,tovariousothertransformeroperators,includingtransmission anddistribution companies, generatingcompanies, andlargeindustrial companies.

Overview–TransformerAnalysis

GoalsoftheAnalysis?• Determinethehealthofourcriticaltransformers• ImproveourTransformerFleetReliabilityPerformance• Consistentupdatingofinformationforstrategicplanningandmaintenance• Haveadocumentedassessmenttodriveplanningandmaintenance

Process

• Component scoresforseveralfactors– eachscoredlogarithmically:• Core/windings

• Dielectric• Thermal• Mechanical

• Oil• Ageing• Contamination

• OLTC• Exteriorcondition• Andotherfactors

• Combined intoanoverallscoreusingadditionoflogscores• Poorscoresstandout• Overallscoreisgiven inthreeways:

• ‘Now’basedonlatestassessment• ‘Mitigated’aresultofintervention• ‘Possible’improvementasaresultofintervention

OLTC ExteriorT-No Ratio Rated PowerManufacturerDesign FamilyDesign ScoreYear Now Mitigated Possible ImprovementDielectric Thermal Mechanical Ageing ContaminationT4315 400/132 kV 240 MVA AEI WythenshaweA04a 32 1965 221 213 8 100 100 1 13 10 3 10T3040 275/132 kV 120 MVA EEC E11b 32 1959 170 103 68 30 60 1 190 10 10 10T6975 400/275 kV 1000 MVA GEC G02b 104 1994 170 135 35 30 60 36 100 1T3039 275/132 kV 120 MVA EEC E11b 32 1959 154 143 11 30 100 1 23 10 10 3T4259 275/66 kV 180 MVA CP D07 12 1965 152 126 26 60 60 1 70 10 1T2370 275/132 kV 120 MVA MVE M01 5 1957 151 94 57 30 60 1 160 10 3 10T5961 400/275 kV 750 MVA HHE H02 111 1971 147 100 47 3 60 140 3T6201 275/33 kV 100 MVA PPT P21 104 1972 144 139 5 1 3 100 13 1 10T5566 400/132 kV 240 MVA CAP C04 32 1968 138 85 54 10 60 1 140 30 1T4409 275/132 kV 240 MVA HHE H07a 12 1964 133 107 26 1 100 1 70 10 3T5581 400/132 kV 240 MVA AEI WythenshaweA04b 102 1967 132 106 26 10 60 1 70 10 3T4686 400/132 kV 220 MVA PPT P06a 131 1967 131 107 24 1 60 1 63 10 1 10T4406 275/132 kV 240 MVA HHE H07a 12 1964 129 106 23 1 100 63 10 1T2300 275/132 kV 120 MVA EEC E11a 102 1955 129 105 24 10 60 1 70 1 10T4258 275/132 kV 240 MVA HHE H07a 12 1966 129 106 23 1 100 63 10 1T3041 275/132 kV 120 MVA EEC E11b 32 1959 129 107 22 30 60 3 43 30 10T2521 275/132 kV 120 MVA FER F08 120 1956 124 105 19 3 60 1 50 10 1T3583 275/132 kV 180 MVA FUL L05 111 1962 122 99 23 1 60 63 10 1T5434 400/132 kV 240 MVA AEI WythenshaweA04b 102 1967 122 96 26 1 60 70 10 3T3139 275/66 kV 120 MVA AEI Rugby A10 3 1960 122 106 16 100 3 1 40 10 1

Overall Condition OilCore and Windings OLTC ExteriorT-No Ratio Rated PowerManufacturerDesign FamilyDesign ScoreYear Now Mitigated Possible ImprovementDielectric Thermal Mechanical Ageing ContaminationT4315 400/132 kV 240 MVA AEI WythenshaweA04a 32 1965 221 213 8 100 100 1 13 10 3 10T3040 275/132 kV 120 MVA EEC E11b 32 1959 170 103 68 30 60 1 190 10 10 10T6975 400/275 kV 1000 MVA GEC G02b 104 1994 170 135 35 30 60 36 100 1T3039 275/132 kV 120 MVA EEC E11b 32 1959 154 143 11 30 100 1 23 10 10 3T4259 275/66 kV 180 MVA CP D07 12 1965 152 126 26 60 60 1 70 10 1T2370 275/132 kV 120 MVA MVE M01 5 1957 151 94 57 30 60 1 160 10 3 10T5961 400/275 kV 750 MVA HHE H02 111 1971 147 100 47 3 60 140 3T6201 275/33 kV 100 MVA PPT P21 104 1972 144 139 5 1 3 100 13 1 10T5566 400/132 kV 240 MVA CAP C04 32 1968 138 85 54 10 60 1 140 30 1T4409 275/132 kV 240 MVA HHE H07a 12 1964 133 107 26 1 100 1 70 10 3T5581 400/132 kV 240 MVA AEI WythenshaweA04b 102 1967 132 106 26 10 60 1 70 10 3T4686 400/132 kV 220 MVA PPT P06a 131 1967 131 107 24 1 60 1 63 10 1 10T4406 275/132 kV 240 MVA HHE H07a 12 1964 129 106 23 1 100 63 10 1T2300 275/132 kV 120 MVA EEC E11a 102 1955 129 105 24 10 60 1 70 1 10T4258 275/132 kV 240 MVA HHE H07a 12 1966 129 106 23 1 100 63 10 1T3041 275/132 kV 120 MVA EEC E11b 32 1959 129 107 22 30 60 3 43 30 10T2521 275/132 kV 120 MVA FER F08 120 1956 124 105 19 3 60 1 50 10 1T3583 275/132 kV 180 MVA FUL L05 111 1962 122 99 23 1 60 63 10 1T5434 400/132 kV 240 MVA AEI WythenshaweA04b 102 1967 122 96 26 1 60 70 10 3T3139 275/66 kV 120 MVA AEI Rugby A10 3 1960 122 106 16 100 3 1 40 10 1

Overall Condition OilCore and Windings

Leaguetablefortransmission operator– sortedbyworstoverallconditionscore

Outcome

Component scorebasedonsub-components

CurrentandMitigatedCondition



PossibleimprovementinscoreDesign/Manufacturer



System:WhichTransformerstoReplace?

• Ranking system developed by utility

• Initial Risk = Health X CriticalityHealth = (Initial Health + Dynamic Health)

• Final Risk = (Initial Risk X Age Factor) + LTC Type Factor

Ranking

• Ranking is Done Using the Final Risk

• Failure mode?

NAME Position Equip.Class

MFG_NAME Health Criticality InitialRisk FinalRisk Ranking

SubstationA TR01 13KV MFGA 141.7 1.2 170.04 210.04 1SubstationB TR05 35KV MFGB 71.7 1.9 136.23 203.04 2SubstationC TR03 13KV MFGC 131.7 1.2 158.04 193.84 3SubstationD TR02 13KV MFGA 76.7 2.1 161.07 181.07 4SubstationE TR01 13KV MFGB 56.7 1.35 76.55 164.21 5SubstationE TR02 13KV MFGD 36.7 1.55 56.89 142.58 6Substation F TR06 13KV MFGA 59.7 1.8 107.46 138.21 7SubstationG TR01 35KV MFGB 56.7 1.3 73.71 137.4 8SubstationH TR03 13KV MFGB 71.7 1.55 111.14 136.7 9Substation I TR03 35KV MFGE 41.7 1.2 50.04 130.04 10Substation J TR04 13KV MFGD 83.3 1.55 129.12 129.12 11SubstationK TR02 13KV MFGD 54.7 1.35 73.85 128.62 12Substation L TR04 13KV MFGE 41.7 1.55 64.64 127.87 13SubstationM TR01 13KV MFGF 46.7 2.05 95.74 125.31 14

RevisitingtheWaterfall

Howdoyouknowwhichmode?Howdoyouknowthetimescale?

RevisitPlanningIntervention

Collect data: condition, operation, family/design, industry etcAnalyze data: looking for anomaly and outliersID anomaly: based on individual asset data, which may combine condition and operation data or

aggregate data across several assets or asset typesDiagnose: find possible causesPrognosis: what is likely to happen, with what consequences, when?Intervene: replace a failed unit; repair/refurbish a unit that is failing ‘gracefully’; plan longer term

investment; provide assurance via monitoringMonitor: analyze, review , and check interventionIterate: further data collection

IEEE “Data and Decisions” 2011 Smart Grid Conference, Perth, Australia Howdoyouknowyouractionsareworking?

• Possibledefinitions:• Rawdatais‘measured’• Deriveddatais‘calculated’

Areyouusing‘Rawdata’or‘Deriveddata’

Whatdoesthismean???

Whocancheck?

• Using:• Populationstatistics• Modesoffailureinoperationandtimescale• Identifyindividual probabilities andsum?• Identifyexposure ofeachrisk(theexpected annualvalue)andsum?

• Acceptability offailure– this isasset riskmanagement• Needgoodstatistics orgoodestimates

• Wheredidouroriginaltimescales foractioncomefrom?

WorkingonaProbabilityofFailure

33

ProbabilityandUncertainty

• Probabilitycanbecalculatedprecisely• Uncertaintymustbeestimated

• Riskmanagementcombinesprobabilityandconsequence

• Gooddecisionsmaystillhavebadresults• Let’srolladice:ifitcomesupasanyof1-5youwin$1000• Ifitcomesupasa6,youlose$10• Theexpected valueisyou‘win’>$800…butyoucanstilllose!

©2015DobleEngineeringCompany.AllRightsReserved 34

AssetManagement:Conditionranking,riskranking

Modeoffailure…timetofailure…whatdoestherawdatasay?

AssetManagement:Conditionranking,riskranking

Needtoseethedetails

Summary:AssetHealthIndex(AHI)

• AHIisanestimateofagenerallyunknownvariable:theactualtransformerhealth• Estimatingwhat– healthyenoughtodowhat,exactly?• Moredata,shouldbeabetterestimate?

• Theindexshouldbeuseful– whatdoestheletter/numbermean:• Answeraquestion…

• Anindexshouldhaveassociatedaction &timescale• Timescalesshouldcalibrate– beconsistent

• Howtomakeituseful?• Supportdecisions:justifyactionsinanauditablemanner

TonyMcGrailDobleEngineering Company

[email protected]

Thankyou!

AnyQuestions?

Documents

Generating Asset Health Indices which are both …...Definitions (from ISO 55000) Term Working Definition Asset an item, thing or entity which has value or potential value Asset Management