Transformer Losses

Electric System Losses July 2010 Siemens

Siemens

© 2010 Siemens Energy, Inc. All rights reserved Siemens Energy Inc., Siemens Power Technologies International Exclusive Copyrighted Property notes inany way. participants maynotmakecopiesorshare thecourse each participantsown future reference.Course use thecoursenotesfor completionofthecourseandfor Technologies International. Course participantsmayonly property ofSiemensEnergy, Inc.,SiemensPower electronic orotherwise, are theexclusivecopyrighted Course notesprovided to cour

Siemens se participantsinanyform, 3 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010      Siemens Energy Inc., Siemens Power Technologies International Course Outline Methodologies forLossCalculations Equations and Definitions Loss CalculationsBasics andTerminology Data Requirements Basic Concepts

Siemens

© 2010 Siemens Energy, Inc. All rights reserved     Siemens Power Transmission & Distribution, Inc., Power Technologies International Why electriclosses? period, usually ayear Losses aremeasured orcalculated foragiven time operation minimum dictated bytheeconomics ofthepowersystem Electric lossesshould benothigherthan theabsolute normal operationofthe powersystem Energy (kWh)andpower (kW)lossesresultfrom the heat inelectricalconductors andequipment Electric lossesoccurasenergy istransformedintowaste

Siemens 2 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Why theNeedtoKnow ElectricLosses? Electric lossescanbereduced – Electric lossisawasteofmoney andresources In lossstudies thefollowingisdetermined, . . . .

Money savedinlossreduction Loss reductionmayrequires moneyinvestments targeted for lossreduction measures or areas ofthesystem havingunusually highlosses canbe How the lossesaredistributed in the system.Therefore, elements Total electric system losses

Siemens ≥ Money invested not eliminated

3 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010      Siemens Power Transmission & Distribution, Inc., Power Technologies International Why theNeedtoPerform LossCalculations? System iscomposedof averygreat number Loss measurement inevery elementisimpossible– Electric lossesoccurinevery valuable sourcesof information forloss studies SCADA andData Management Systemrecords arevery equations, yield fairlyaccurateresults The calculation oflosses,usingstandard engineering least fornow

Siemens system element

of elements

4 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Load andLossEquation Load Load Loss Loss i i i i 

i Siemens   s forLossCalculation PLP 10 Lossi 20 LCCP 2 10 i  i  2 LCLCCP 2 2 ii LCLCCLP 2 ii 5 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Transmission System LoadandLosses Load (MW) 1500 1700 1900 2100 2300 2500 2700 2900 3100 3300 3500 0 0 1010 2100 1600 1100 600 100 Transmission System Load and Losses Siemens Hours Transmission System Load Difference areTransmission Losses 6 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International Energy Losses Energy losses into another formofenergy: Energy islost whenisconvertedfrom oneformofenergy basic lawofPhysics– Energy isneverlost,it only changesitsform.Thisisa example, whenelectricity flows through conductors Electric energy isalso lostwhen itistransported, for . . .

Electrical tomechanical (motors,etc.) Mechanical to electrical(generators,etc.) Do wereallyloseenergy?

Siemens Principle ofConservation ofEnergy Principle

7 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010  input point Starting or Siemens Power Transmission & Distribution, Inc., Power Technologies International Energy Losses(continued) to theultimatecustomers distribution ofenergy from ge Electric energylossesresult from thetransmissionand

nryosEegIptEnergyOutput EnergyInput EnergyLoss Energy input Siemens  Process, Process, event Loss nerators ortie-linesources  Energy output output point Ending or 8 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010

drops andcustomermeters the transmission system down Losses occurateachdelivery, se Siemens Power Transmission & Distribution, Inc., Power Technologies International Electric SystemLosses Technical Losses Technical Losses Transmission System Transmission Distribution System Distribution SiemensGeneration System Sales tothe120/240-voltservice rvice, orvoltagelevel, from Own-use (notOwn-use considered to be losses non-technical losses be neglected) may High Voltage Customers (assumes that (assumes Customers Voltage High Non-Technical Losses 9 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010  Siemens Power Transmission & Distribution, Inc., Power Technologies International Electric SystemLosses (continued) Energy input Losses onnetwork elements 

System losses

Network element Siemens Loss Energy output  EEE ioSL  EE EE  ioL   10

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Energy andPowerLosses Energy lossesarecomposed of: how quicklytheenergy isbeinglost Power lossisenergylost perunitoftime.Itexpresses example, ayear Energy loss isenergylostinaperiod oftime,for . . .

Electric Power lossisalso Energy losses(expressedin kWhorMWh) Power losses(expressedin Watt,kW,orMW) nryPwrTime Power Energy

kh k)(hour) (kW) (kWh) Siemens  referred toas “demandloss”  11

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Again, Why Energy LossesNe particular, dueto: system lossesingeneral, anddistributionlossesin There isanincreasing interest inthestudyofelectric systems system losseson theoperation andplanning ofpower Electric utilities areassessing the effectsof electric . . . .

management techniquesandreducelosses ingeneral Increased pressure fromregulatorybodies Difficulty ofsiting Increase ofcapitalcost Increase ofcostelectric energy andpower

Siemens new generation

ed tobeDetermined? to improveloss

Siemens Distr. Powr. Purch. Sales Equipment Costs Equipment O&M ucinl5% Functional $ Capital $ Capital & Labor oss10% Losses Labor Land Aprox. % Aprox. 70% 10% 5% 13

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Basic LossConcept built-in the power systems,atacost losses, additional capacitieshave to be that willbe lost,atcertainpower To produce andtransport theenergy Lost energyhasadirect cost components intheirfinancial impact: Energy losseshavetwo main

Siemens Due toenergy losses there Capacity Energy costs costs are: & 14

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Incentives toReduce Losses The costofsupplyingenergy isimpactedby, ways to reduce losses. ways toreduce Distribution companies keepchecki . . . . .

Pressure bythe investorsfo to regulatingbodies forthe Pressure Location ofthe loadcenters andelectriclines substations electrical grid.Additionalland andri ofsitelocationsfor Availability Cost andavailabilityofcapital

Siemens r ahigherrate of return in relationtothe generation new generationinrelationto ng their systemstrying tofind ght ofways needto be securedfor keep the price ofelectricitylow keeptheprice the

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010      Siemens Power Transmission & Distribution, Inc., Power Technologies International Who Pays,isResponsible? the financialimpactof losses? Electric losseshaveafinancial impa Answer: Consumers pay Who is responsible for the losses?, where do they happen? Who isresponsible forthelosses?,where dothey ones responsible, as the losses occur in their networks ones responsible, asthelossesoccurintheir Answer: Power companies(system upgrades thatmayresult inareduction oflosses Consumer andnetwork userspay forthenetwork improvements and

Siemens operators and planners)arethe ct. Question is, who does pay for pay does ct. Questionis,who 16

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010      Siemens Power Transmission & Distribution, Inc., Power Technologies International Minimum CostObjective… financial impact Losses canandshouldbereduced result inhigherlosses On oneside,relativelyinexpensive networkupgradesolutions,may point ofreducing losses,mayberelatively expensive On theotherside,best networksolutions,fromthepointof improvements basedongoodandcreative management The goodnews isthat,therealwaysroom forefficiency overall cost optimization andin network upgrade alternatives thatminimize the Consumer andnetwork usersare interested in an overall

Siemens to decreasetheireconomic and

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International …Minimum CostObjective Quality ofinputdatais veryimportant over therighttimehorizon Only relevantcostsshould betakenintoaccountand It isabalancingactto find theoptimalsolution

solution network cost of plus losses Cost of

Siemens Inefficient Optimum Efficient losses regard to efficiency with Network 18

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Determined?… Again, WhyEnergyLosses Needtobe Also, electricenergylosses aredeterminedforratemakingpurposes the deliverysystem.Forexample, the partiesresponsiblefor creating thelossesasenergytravelsover Energy lossesmustbeaccounted fo . . .

distribution secondary systems load creates inallthr The secondary distribution customerisresponsiblefor lossesthatits ary andthetransmission systems from itsloadon boththeprim The primarydistribution customeris load causesonthetransmission system The transmissioncustomeris respon

Siemens ee systems (transmission, r inratedesignandallocated responsiblefor thelossesresulting sible onlyforthoselossesthat its distribution primaryand to to

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Determined? …Again, WhyEnergy LossesNeedtobe energy multipliers Information above isprovided by power and of 1.071kWh should pay fortheproduction andtransportation the losses.Therefore, theresidentialcustomer 1.071 kWh,tosupply thiscustomerandtocover have toprovidemore thatonekWh,let’ssay one kWhofenergy, thegenerationsystemwould For example,ifaresidential customerrequires

Siemens 20

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Loss Analysis Loss analysisstartwith informationavailable assumptions or approxim As technological advances are implemented, theneed for required to perform thelossanalysis Approximations orassumptionsare sometimesare Information availableisnot . . . . .

Allocate demand andenergylossesbysubsystem Determine demandandenergy lossesbysubsystem Results aretotalenergylosses Adjust andtakethedifference Energy salesandinputs

Siemens ations are less necessary always good orsufficient. 21

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Siemens 23

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Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International System PowerFlows Generation Loop Flow Wheeling Imports Transmission System Siemens Distribution Generation Loop Flow Wheeling Primary Exports Losses To

Distribution Primary System Distribution Secondary Industrial Losses

Other To

Distribution Secondary Commercial Residential Industrial Losses Other

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010       Siemens Power Transmission & Distribution, Inc., Power Technologies International Locate theMetersand Sources ofData Company use, street lights, traffic lights Most customer load Distribution circuits Distribution substation transformers Control area,utilityboundaries Generator stepuptransformers

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the transmission anddistribution networks distribution businesses that itisnotcharged forbyneitherthesuppliers northe thesense energy islostin reason, isnot recordedassales;this Some energy is actuallydelive Energy unitsthatarephysically lostduetothephysicalnature

Siemens red andconsumed but,forsome of

included as 240/120, 480/277, etc.).Lo Secondary Distribution system(usu utility ortransmission operator) or lower.Upper endofvoltagerangevaries, dependingonthe Primary Distribution system(usuallyoperating atvoltages34kV Transmission toDistribution transformers voltages 69kVorhigher Transmission andsub-transmission

Siemens on anddistributionsystems sses in customer meters are systems(usuallyoperating at ally operating atvoltages such 28

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Non-Technical Losses… Non-technical lossesinclude factors suchas: Non-technical losses canbe estimated Non-technical lossesaresmall(usually lessthan1%) . . . .

Energy diversion (theft) Meter readingerrors Metering errors(equipment calibration,etc.) use, streetlights,traffic etc.) Un-accounted loads(substation

Siemens light andpower,government 29

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International …Non-Technical Losses Meter errors Errors inaccounting fortheun-metered supply Measurement errors inthesettlement system Energy Diversion orTheft . . . .

Recently manufacturedmeters aremoreaccurate applied Depends onelectricitymarket arrangementsandtechnology E.g. theiraccuracyco utility’s consumption etc.)andhow good areinventory data lights, trafficlights andcameras,telecom masts,distribution Depend onhow muchconsumptionisun-metered (e.g.street

Siemens uld be-3.5%to+2.5% 30

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International System LossesFromActual StudiesinU.S. TOTAL Losses - % Losses TOTAL Losses - Non-Technical % Secondary Distribution Losses - % Distribution Losses- Primary % Transmission to DistributionLosses - % Losses - Transmission % Maximum Demand- MW Total Energy- Consumption Total Energy- Consumption - GWH

Siemens Electric System Losses-% 21,456 100.0 3,384 33.1 20.3 16.5 29.2 0.9 1 100.0 4,918 27.3 25.4 15.6 31.6 987 0.1 2 COMPANY 31,680 100.0 6,419 20.4 48.8 8.7 0.1 22 3 22,800 100.0 4,000 36.3 28.7 35 0 4 - 31

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Energy Lossesby Origin (37%ofdemand) Siemens Power Transmission & Distribution, Inc., Power Technologies International In SomeCasesLosses areVeryHigh…

26% Siemens 3% 8% Subtransmission losses technical Distribution losses non technical Distribution losses 32

© 2010 Siemens Energy, Inc. All rights reserved 6. 5. 4. 3. 2. 1. Siemens Power Transmission & Distribution, Inc., Power Technologies International Typical DataRequirements andCalculations… Hourly loads at every service level for entire study period summary Power pool interchange Energy balance Average energyuseby customer Energy usebyrateclass orservicelevel Active electricservices

Siemens 2 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 13. 12. 11. 10 9. 8. 7. Siemens Power Transmission & Distribution, Inc., Power Technologies International …Typical DataRequirements andCalculations… . Transmission transformer inventory (load & no-load data) &no-load (load inventory Transmission transformer Data for Coronaloss calculation Transmission power flowcases Generation output summary Transmission tielinesummary If notprovided,loadandloss factor Load/loss factorforentiresystem andforeachsub-system

Siemens s canbecalculatedorestimated 3 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 16. 14. 18. 17 15. . Siemens Power Transmission & Distribution, Inc., Power Technologies International …Typical DataRequirements andCalculations… . Calculation of TransmissionSystemLosses Calculation ofsubstation transformer losses(Load andNo-load) transformers shouldbeincluded as the plantmeterisongenerator side,thelossofGSU loss calculationdepending onwhere Load lossesofGSUtransformers ma Distribution substation transformer inventory substationtransformer Distribution Generator Step-Up(GSU)transformer inventory Distribution secondary transformer inventory

Siemens partofthetransmissionlosses. y ormaynotbeincludedin the the plantmeterislocated. If 4 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 23. 22. 21. 20. 19. Siemens Power Transmission & Distribution, Inc., Power Technologies International …Typical DataRequirements andCalculations… no-load losses) Calculation ofsecondary and servicedrops losses Secondary and servicedrops characteristics anddata Calculation ofprimarycircuitlosses Distribution primarycircui t characteristicsanddata Calculation ofSecondary Transformerlosses(loadand

Siemens 5 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010      Siemens Power Transmission & Distribution, Inc., Power Technologies International …Typical DataRequirements andCalculations Calculation ofTotal SystemLosses Energy diversion estimation Unmetered load andenergyuseestimation Calculation ofcustomer meterlosses Customer meterinventory

Siemens

© 2010 Siemens Energy, Inc. All rights reserved  Siemens Power Transmission & Distribution, Inc., Power Technologies International Sub-systems forLoss Calculations… systems: Loss calculationsareperformed foreachofeightsub- 1. 2. 3. 4. 5.

Generator step-uptransformers (GSU’s) Transmission lines(usually, 69kVandabove) Transmission transformers (69kVandabove) 13.2, 12.7, 4.16kV, etc.) Distribution primary lines(atvoltagessuch as34.5,25.0. 13.8, primary voltage anddistributionlevelsecondary voltage) Distribution primary transforme

Siemens rs (withtransmission level

2 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International …Sub-systems forLoss Calculations    level primaryvoltageandsecond Distribution secondarytransforme rs (withprimarydistribution voltage) Distribution secondarylines (440,240,120volts,etc.) Customer meters

Siemens ary distributionlevelsecondary 3 Understanding System Losses

© 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010      Siemens Power Transmission & Distribution, Inc., Power Technologies International General Procedure Calculate energy lossmultipliers Calculate demand lossmultipliers determined from salesdata Adjust energy lossestomatchtotal systemlossas demand loss(kW) Calculate energyloss(kWh) foreachsubsystemfrom the Calculate demandorpower (kW)lossesbysub-system

Siemens 4 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010        Siemens Power Transmission & Distribution, Inc., Power Technologies International Load DataCollection Metered customerssales series – Customer load research– Generator output– Transformer meters(hourly kWdemand foreach transformer) Sales toLarge customers– Interconnection pointsinand out Distribution lineloadings perph

hour by hourestimationofloadusing statisticalmethods)hour

Siemens (timeseries– kW

where mete kW (time series– kW

ase ortotal (amps,kW, Kvar,kWh) – kW (timeseries- kW hour byhour) hour red dataisnot available,(time

hour by hour) hour

hour byhour) hour

5 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010       Siemens Power Transmission & Distribution, Inc., Power Technologies International Definitions andTerms UsedinLossStudies Power factor Diversity factor Coincident factor Loss multipliers Loss factor Load factor

Siemens 6 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International Load Factor andLossFactor… factor iscalculated foreachsub-system and theentiresystem number ofhours intheperiod(f study tothepeak loss(kW)duringthesameperiod multipliedby the entiresystem hours forayear).Loadfactor isca multiplied bythenumberof hoursin period ofstudytothepeak demand(kW)duringthesameperiod Load factor (kW) inthe same period Loss Factor isequal to theaverage demand (kW) inthesameperiod Load Factorisequaltothe average demand(kW)dividedbythepeak Loss factor

is theratioof the totallosses is theratiooftotalenergy(kWh) suppliedduringthe

Siemens or example,8,760 forayear).Loss lculated foreachsub-system and loss (kW) dividedby thepeakloss theperiod(forexample,8,760 (kWh)during theperiodof the

7 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International …Load Factor andLossFactor… Load FactorLoss Factor Siemens   Loss P max loadkWh losskWh 760,8max* 760,8* , , unitper unitper 8 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International …Load Factor andLossFactor The maximum demandloss,Loss data determined frommetered data, orfrom loadresearch The kWhloadandthe maximum demand,Pmax,are system The loadandlossfactors canbecalculatedforeverysub- metered or load research data metered orload research data, for non-coincident peak from powerflow solutions, orequipment manufacturer’s

Siemens demand conditions, using MAX , canbedetermined

9 Understanding System Losses

© 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Calculation ofEnergyLo is the hourly loadof thesub-system The basic datafor thecalculat loss factorcan beestimatedfrom theloadfactor time, usually ayear.Ifthesevalues arenot available,the the totalkWh lossandthepeak foragivenperiodof Loss factorforeverysub-system canbecalculatedfrom time, usuallyayear total kWhloadandthe peak Load factorforeverysub-syst

Siemens sses fromLossFactors… load foragivenperiod of em iscalculatedfrom the ion of loadandloss factors 10

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International …Calculation ofEnergyLosses fromLossFactors sub-system can becalculated fromthenon-co Once theloss factorisknown,th radial systems butitshouldno with anerrororlessthan1%. This from theloadfactor.Theestimation If thehourlyloadsarenotknown, load arealwaysknown. Thesevalu not available.Thisisbecause thetotalkWhloadandthepeak kW thehourlyloadsare ed, evenif Load factorscanalwaysbe calculat method is used For the energylosscalculation of

Siemens t beusedinlooped systems e energylosses forthesub-system thetransmission system other thelossfactorcanbeestimated typeofcalculationworkswell in incident peak demandlossofthe es areverybasicpiecesofdata issufficientlyaccurate,usually 11

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010  Siemens Power Transmission & Distribution, Inc., Power Technologies International Load andLossFactors Examples Area (EEI) Control 0.499 Primary Secondary 0.462 0.263 0.229 Load andLossFactors – change significantlyfrom oneyeartothenext Subsystem for 2004 Subsystem for

Siemens FACTORSAND LOSS LOAD SUBSYSTEM Load Factor Load Factor typically, thesefactors donot 0.503 0.503

Loss Factor Loss Factor 0.265 0.265 12

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Load (MW) 100 200 300 400 500 600 Siemens Power Transmission & Distribution, Inc., Power Technologies International Hourly LoadsfromResearch Data 0 0123456789101112131415161718192021222324

Siemensone hour. over some time period such as Load research data integrated Time (Hours)Time 13

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 System Load (MW) 100 200 300 400 500 600 Siemens Power Transmission & Distribution, Inc., Power Technologies International Load Factor 0 101112131415161718192021222324 9 8 7 6 5 4 3 2 1

Siemens Load Factor = 0.815 Average Hourly Load Hourly Time (Hours)Time Load 14

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Calculation ofLoadFactor fromHourlyLoads L i =Unit of time(i.e T =Period ofCalculation(i.e.8,760 hours) F F i Load Load = Average loadduring time “i”, inperunit ofthe

= LoadFactor maximum load during the period

 T Siemens 1 *  i T  one hour) 1 L

i 15

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Calculation ofLossFactor fromHourlyLoads L i =Unit of time(i.e T =Period ofCalculation(i.e.8,760 hours) F i Loss F = Average loadduring time “i”, inperunit ofthe = LossFactor

Loss maximum load during the period

 T Siemens 1 *  i T  1 one hour) L 2 i

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Per UnitLoad/LossRelationship Per Unit 0.00 0.20 0.40 0.60 0.80 1.00 1.20 01 21 41 61 81 02 22 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1

Siemens Loss FactorLoss = 0.679 Load Factor = 0.815 Per Unit Load Squared Per Unit Load Time (Hours)Time 17

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Empirical Calculation ofLossFactor calculated from the kW Once the lossfactor isknown, thekWh lossescan be always beestimated the lossfactor cannotbecalculated accurately,itcan uses verybasic datathatisal Calculation ofloadfactors is relationships canbeused isnotavailable,empirical calculation data forsuch If thedetermination ofloss factorsisinconvenientorthe

Siemens losses foreverysub-system alwayspossiblebecause it ways available. Therefore, if 18

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Gustafson’s Loss Equation Gustafson’s LossEquation be determined from actual load data For other countries, ane The exponent isapplicab Where: L L LL Load Loss Loss Isthe LossFactor. Isthe LoadFactor. Siemens  912 1 Load . w exponent may needto w exponent le toUSA systems only. 19

Siemens )1( Load  xLLxL 2 Load 20

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010      Siemens Power Transmission & Distribution, Inc., Power Technologies International Loss Terminology… Demand The demand lossmaybecoincident equations anddata Demand lossescanalways becalculatedusingsuitable Non-coincident loss occurs at non-peak times lossoccurs atnon-peak Non-coincident system peak. The lossiscoincident whenitoccurs athetimeof

Losses –

Siemens are powerlosses(kW).

or non-coincident

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International …Loss Terminology Coincident Factor Non-Technical Losses Non-Technical calculated usingequations Total Losses = Technical + Non-Technical considered anon-technical loss Usually called “energydiversion”. Electricenergytheftis be determined usingequationsor arationalmethod. Technical Losses to thenon-coincident demand (kW)

Siemens– – Losses thatcanbetechnically

Ratio ofthecoincident demand(kW) Ratio

–

Unaccounted lossesthatcannot Unaccounted

or measuredbyequipment 22

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Coincidence Factor The CF =D individual maximumdemand demand ofasetusers tothesummationofset’s Coincident Factor isthereci

Coincident Factor 1tp+2tp+….+Ntp

Siemens /(D 1t1

+D is theratioofmaximum 2t2

procal oftheDiversity Factor …+D

Ntn )

Diversity Factor 1t1 +D 2t2

Siemens…+D

Ntn is theratioofsum of thenon- )/ D1

tp+2tp+….+Ntp of twoormoreloadsto

(kW/kVA)

Siemens is theratioofrealpower (kW)toapparent

andtime.Generally,it is Kw Kva 25

Siemens

© 2010 Siemens Energy, Inc. All rights reserved      Siemens Power Transmission & Distribution, Inc., Power Technologies International Important Equations Per unitsystem Basic equations Power andVAr Reactive power balance Real powerbalance

Siemensequations

2 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Real PowerBalance WSystem Loss(MW) MW System Load (MW) InputPower Generated(MW) MW MW F F   ls ld gen Frequency(Hz) f    () Siemens MW gen  MW dls ld  MW 3 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Reactive PowerBalance V = Voltage (kV) Voltage = V V= MVAR MVAR MVAR f ls ld gen = Reactive Power Losses Power (MVAR) Reactive = () = Reactive Power Load (MVAR) Power Reactive = = Reactive Power Generated (MVAR) Generated Power Reactive = M SiemensVAR gen  M VAR dls ld  M VAR 4 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Power andVAREquations E S Q P S S X Siemens E R Q P S S   E X R X * EE S *(* RS *

Sin

   SR ECosE RSR ) 5 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Power Equations I power (complexnumberorphasor) S =Apparent S =ExI E =Voltage (complexnumber) Where: S = P+jQ S =Ex IxCos * = ConjugateofCurrent (complexnumber) *

φ Siemens – j ExI Sin

φ 6 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Basic Equations I IER P R PI

1      E

SiemensR 2 MVA / 2 3

3  KV 3 LL  1000 7 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Voltage DropDiagram V s V L Assuming that V = V s -I Z = V

SiemensS θ –I S I (R+jX) = 1 pu R +jX



Note thatV I

-j IX L V -IR L < 1 pu

V L V S LOAD 8 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Per UnitSystem Typical Base VoltageisNominal atSystemLocation Typical BaseImpedance – Distribution BaseValue=1,000kVA Transmission BaseValue =100MVA Per UnitValue= SiemensTypical BasePower-Selected Physical Value Base Value Requires Calculation

9 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Per UnitBaseChange ZZ Typical use is tochangetransformer impedance,RandX. Ue PUold PUnew

Siemens S S

3 3

  basenew baseold 10

V I    1φ BaseLN BaseLN 3 = 3xV V

SiemensS

 3   V S BaseLL

2  LN   BaseLL base x I

L = √

3 xV LL x I

L 11

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Where, rms valuesareuseddefined asfollows: Siemens Power Transmission & Distribution, Inc., Power Technologies International Instantaneous Power inACCircuits little work... Using wellknowntrigonomet The instantaneouspower is

p(t) = I     1 V 2

Siemens I max  max I    [cos  titvtp     θ  (1 -  cos(2 max ric identitiesandwith a

V t)) -  tsinItsinV 1 sinθ 2  V

max sin(2

 t)] 12

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International AC Circuits Instantaneous Voltage, Current&Power in Frequency of pis 2times that ofV or I. Negative p(t):the source takesenergy Positive p(t):the source supplies energy

Siemens 13

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010  P - The instantaneouspower p  Which is also theaveragevalue the peakvalue of P =|V||I| cos Siemens Power Transmission & Distribution, Inc., Power Technologies International Active andReactivePower the P (t) =|V||I|cosθ

reactive powercomponentsas shownbelow: Equation abovecanbearbitrarily split which is always positive positive always which is

active power

θ [watts, W] p(t)= (1 -

p P cos (2 (t) isP:

V I



Siemenst))  equation, [cos

θ (1-cos(2 into two components, Q -  Q =|V||I| sin the peak valueof p Average value iszero t))-sin Q the (t) =|V||I|sin (t) reactive, orVAR]

reactive power Which is positive and negative andnegative ispositive Which zero averagevalue andhasa during equaltimes

θ sin(2

θ , [volt-amperes θ sin (2  p t)] Q (t)

 t) called activeand is Q: is

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Instantaneous P&Qin ACCircuits and Q: a phasorwhose realandimaginary componentsareP and theso called “apparent” and Q.Therefore, thetrigon The usefulinformation inthis reactive poweris: The instantaneouspower asa

p(t) =P(1- Siemens cos (2 S =P+ jQ

 t)) - ometric terms are neglected power may beinterpretedas expression iscontainedinP function oftheactiveand

Q sin(2 Q

 t) [W] 15

Power going outof load Power going into circuitel Power going |I| =rmscurrentmagnitude inAmps |V| =rmsvoltage magnitudeinVolts θ

= phaseanglebetween VandI

Siemens power fromavoltageVandcu

ctangular components: ned asthefollowingphasor: Q = |V||I|sinθ Q = P = |V||I|cos P = is negative (generators) ement is positive(loads) S =VI* θ rrent lundersteadystate 16

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Apparent PowerinAC Circuits    etc P isrelated toenergythat beco a phasorwithcomplexvalue The steadystateapparentpower inAC circuits can be expressed as capacitance Q is related toenergy that istemporarily stored in an inductance or Q =reactivepower inVAr,kVAr,orMVAr P =activepower inWatts,kWorMW S =apparentpower inVA,kVAorMVA Where, S =P+jQ

Siemens mes heat, light,mechanical motion, 17

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International Power Factor S. Itrepresentsthefraction Power Factoristheratioof theac active powers. current functions. Itisalsotheanglebetween theapparentand Power factor is thecosineof of 0andhasa Qof0(entirelyresistivecircuit) hasa powerfactorangle A loadthathas aunity(1.00)powerfactor fields inthe load inductance or capacitance the same totalresistance inorde or capacitive) draws morecurrent than A load that has a powerfactor

Siemens.F.P P S ofVIdoingactualwork: the anglebetween thevoltageand r toestablish theelectromagnetic cos tive powerPtotheapparent power less than 1.00 (partially inductive lessthan 1.00(partially inductive  anentirely resistive loadwith

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Power Triangle these functions. of Current,andthepower angle, triangle whosehypotenuse isequaltoVoltagetimesthe The activeandreactivepowers canbeimaginedasthesidesofa think of acapacitoras agenerator ofreactivepower. negative andQisnegative. Therefore, powerengineers usually current leadsvoltage (itsangle Assuming that voltageisatzeroangle,incapacitive circuits,the

Siemens S=VI P=VI Cos α * is positive) andthepower angle α α , is thesumofphaseangles of Q=VI sin Q=VI

α “conjugate” α is

Average Value of a sinusoidal current wave Average Valueofasinusoidal current wave RMS Value(also calledeffectivevalu Peak Valueofa sinusoidalcurrentwave(I •

Occurs when the sinusoidal current current when thesinusoidal Occurs

I RMS I average  T 1   0 T T Siemens 1 I peak 2  0 T I peak sin 2 sin

T 

T  dtt dtt  wave is at its maximum amplitude atitsmaximumamplitude wave is e) ofasinusoidal current wave I  peak 0 2 peak )

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 • COMPONENTS OF TOTAL CURRENT TOTAL OF COMPONENTS • • • • Siemens Power Transmission & Distribution, Inc., Power Technologies International Voltage andCurrentRelationship SYSTEM VOLTAGE v(t) VOLTAGE SYSTEM TOTAL CURRENT TOTAL TH VOLTAGE (REALCOMPONENT) WITHVOLTAGE CURRENTIN-PHASE COMPONENT OF COMPONENT OF CURRENT 90 COMPONENT OF θ )( )( = Angle bywhichvoltage v(t) leadscurrenti(t) Imaginary component of current supplies no NET energy NET totheload no ofcurrent supplies Imaginary component v(t)   Real component ofcurrent supp Real component MAX MAX

i(t) X R 

 

tIti  Iti  RMS Iti RMS  i R (t) RMS LOAD RMS O i

X OUT-OF-PHASE WITH VOLTAGE (IMAGINARY COMPONENT) VOLTAGE WITH OUT-OF-PHASE  Siemens (t)

lies a NET energy to theLOAD aNETenergyto lies  t  tVtVtv  t

)sin(2)sin(

)sin(cos2)(

tI o  )90sin(sin2)(  I

RMS   It

RMS  t  o )90sin(sin2)sin(cos2)sin(2)sin( 21

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International (continued) Voltage andCurrentRelationship • TOTAL CURRENT TOTAL Θ AN IMAGINARY COMPONENT, VA RMS RELATIONSHIP BETWEEN • • • IS POSITIVE: RMS VALUE (I RMS VALUE RMS VALUE (I RMS VALUE RMS VALUE(I 

RMS v(t) θ X R RMS ) OF IMAGINARY COMPONENT OF CURRENT: OF IMAGINARY COMPONENT ) OF ) OF REAL COMPONENT OF CURRENT: OF ) OFREALCOMPONENT = Angle bywhichvoltage v(t) leadscurrenti(t) i(t) • ) OF TOTAL CURRENT: ) OFTOTAL REAL COMPONENT OF CURRENT OF COMPONENT REAL tIti R



  D TOTAL CURRENT WHEN ANGLE D TOTAL Siemens I Iti RMS RMS LUE OFREAL COMPONENT, i R (t) LOAD i X

(t)

  t )sin(cos2)(  It RMS • IMAGINARY COMPONENT OF CURRENT IMAGINARY COMPONENTOF X TOTAL R X    II II

RMS

RMS RMS  cos Iti sin RMS t



  o I )90sin(sin2)sin(cos2)sin(2)( TOTAL  I R IIII

XR 22  t  I X o )90sin(sin2)( 22

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 • • • Siemens Power Transmission & Distribution, Inc., Power Technologies International Voltage, Current,&Power Relationship INSTANTANEOUS POWER, p(t),IS USING TRIGONOMETRIC IDENTITI INSTANTANEOUS AND AVERAGE POWER ANDAVERAGE POWER INSTANTANEOUS )(  of instantaneous pow has a non-zeroaverage Note that the real component ofcurrent, I MAX tp )( )(   v(t) “+” RMS MAX

to system.Frequency of  p(t) means system supplies energy tolo IVtp RMS )sin( i(t) IV MAX )()()( 22 

MAX 

er that hasanaver   MAX  value. Theimaginary   )( LOAD 

MAX THE RATEATWHICH ENERGY ES, THEEXPRESSION FORIN

 Siemens

  )2cos(1cos t )2cos(1cos p(t)istwice thatofsystem 

 age value ofzero. 

rms

tItiandtVtv RMS   cos MAX

ttIVtitvtp   )sin( IVt component ofcurrent, I

θ RMS  , produces one component of of one component produces , IV )sin()sin( MAX

ad, “-”

22 

p(t) means load supplies energy back 

STANTANEOUS POWER p(t)IS:

t )2sin(sin IS SUPPLIEDTO THELOAD IS t )2sin(sin RMS sin θ , produces thesecond component the instantaneous power that

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 P • Siemens Power Transmission & Distribution, Inc., Power Technologies International (continued) Voltage, Current,&Power Relationship )( • • • •  THE INSTANTANEOUS POWER CAN ARBITRARILY BE CANARBITRARILY POWER THE INSTANTANEOUS V THE APPARENT POWER THE APPARENT POWER EXPRESSION FORINSTANTANEOUS p AVERAGE POWER SUPPLIED TOTHELOADOV SUPPLIED POWER AVERAGE AVERAGE VALUE OF ACTIVE POWER =P VALUE OFACTIVEPOWER AVERAGE RMS P (t) ANDp  RMS )(  , RMS AND THE RMS VALUE OF THECURRENT,I AND THERMS VALUEOF ACTIVE POWER , p , POWER ACTIVE IVtp RMS RMS

  IVS RMS

QPS IVtp RMS Q RMS

(t) (ACTIVEANDREAC

22  P IVP RMS AV 

   cos T  1

 IN THECIRCUIT,S,IS  T p  0

(t) 

)(



Siemens  )2cos(1cos  Pt TIVE POWER RESPECTIVELY) POWER TIVE   RMS  RMS IVdttp RMS IVt

THE PRODUCT OF THE RMS VALUE OF THE VOLTAGE, THE THERMSVALUEOF OF THEPRODUCT

RMS  RMS ER INTEGERMULTIP cos t )2cos(1)2cos(1cos  :



SPLIT INTO TWO COMPONENTS CALLED CALLED COMPONENTS TWO INTO SPLIT   S P Q

Q )(

• Wattsin   PEAK VALUE OF REACTIVE POWER =Q REACTIVE POWER PEAK VALUEOF t  REACTIVE POWER ,p POWER REACTIVE )2sin(sin RMS LES OF PERIODTIS: OF LES  IVtp RMS RMS IVQ

RMS  sin

Q   (t) )2sin(sin 



 tQt )2sin( 24

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 • Siemens Power Transmission & Distribution, Inc., Power Technologies International (continued) Voltage, Current,&Power Relationship EXAMPLE CALCULATION1 EXAMPLE

POWER (P) AND NO REACTIVE POWER (Q=0), POWER ANDNOREACTIVE (P) POWER MODIFIED LOAD WERE IF THE 2. 1. SHOWSTHEACTIVE TO THECIRCUIT PHASEWI THE CURRENTIN WIRECIRCUI TWO A SINGLE-PHASE WER SUPPLIEDBYTHECIRCUIT? PO WER REACTIVE THE IS WHAT POWE APPARENT THE IS WHAT .1 .2 THEN

GIVEN  RMS IVS : RMS  P 22  QWITH  , 150  V RMS

:0 Siemens kW IN SOME MANNER SUCH THAT IT IT IN SOMEMANNER SUCHTHAT I RMS I RMS ES RMS. A METER CONNECTED 25AMPERESRMS.AMETER RE ISMEASUREDAT = 7620VOLTS  T OPERATES AT 7620 VOLTS RMS BETWEEN THE TWO WIRES. THETWO BETWEEN 7620VOLTS RMS AT T OPERATES R SUPPLIED BY THECIRCUIT? BY R SUPPLIED  (REAL) POWER SUPPLIED IS150 KW SUPPLIED (REAL) POWER V = 25AMPS RMS   P 500,19025*7620 RMS 22  , WHAT WOULD THE LINE CURRENT BE INAMPERES? THELINE CURRENTBE WOULD WHAT IVPS VOLT QPSQorQPS RMS 620,7 000,150    LOAD AMPERES 2 69.19 DRAWS ONLY 1505.190 AMPERES 2   150 kW OF REAL 150 kWOF 5.190 43.117 kVA

kVAr 25

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010  Siemens Power Transmission & Distribution, Inc., Power Technologies International Apparent Power(complex number) apparent power,definedas follow activeandreac The combinationof  Q isrelated toenergy thatisstored inaninductor in½ etc. P isrelated toenergythatbeco mes heat,light, mechanicalmotion,

where then returned to the system in thenext ½ θ Q isthereactive power(VAR) P istheactive power(W) S istheapparentpower(VA) S S = angle –

is theanglebetween thevoltageand current(voltage = P VI

+ j cos Q current angleinthis definition)



+ j

SiemensVI

sin 

s withcomplexnumbernotation: tive powerisreferredtoas cycle.

cycle, and

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Capacitor Application Lumped LoadCase– REDUCING THEI BE LINE CURRENTINTHE REDUCESTHE THIS OF ORALL PORTION SUPPLIES CAPACITOR SUBSTATION Voltage Drop Basic-1.FCW Drop Voltage V I 2 L S R LOSSESINTHELINE (Note: I I C FEEDER O

L Siemens I O Loss ReductionDueto RX

REACTIVE COMPONENT OF LOADCURRENT, OF COMPONENT REACTIVE TWEEN THE SUBSTATION AND LOAD, THEREBY ANDLOAD, THESUBSTATION TWEEN I C | I | V ≤ L | I L | )

LOAD V

L I L IR V Vectors VD With Cap.FCW VD With Vectors S IX I CURRENT I =LINE L = LOADCURRENT V 0 S o '

I L .

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 CURRENT. LOSSES INLINE FROMACTIVE REDUCE NOT WILL PRACTICALLY CURRENT, AND ACTIVE ON THE HASMINIMAL IMPACT CAPACITOR IN THEFEEDER. CURRENT THATFLOWS REACTIVE CURRENT REDUCESTHE CAPACITOR Siemens Power Transmission & Distribution, Inc., Power Technologies International Capacitor Application (continued) Lumped LoadCase– I L I I C O L O Siemens Loss ReductionDueto

REACTIVE CURRENT V L I IR LOAD V Vectors VD With Cap.FCW VD With Vectors S I LINE IX I CAP V 0 S ACTIVE CURRENT ACTIVE O o ' Current Phasors Cap-Detail.FCW With I LOSSES: TO MINIMIZELINE CAP O L = I LOAD

sin θ L

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 SUBSTATION Voltage Drop Basic-1.FCW Drop Voltage WATTS LOSS IN FEEDER WITHOUT CAPACITOR Siemens Power Transmission & Distribution, Inc., Power Technologies International Capacitor Application (continued) Lumped LoadCase– WATTS LOSS IN FEEDER WITH CAPACITOR REDUCTION IN WATTS LOSS FROM LOSS INWATTS REDUCTION W V S WITH LUMPED LOAD, REDUCTION INWA WITH  L CAPWITH 2 FEEDER RIW  WWW  WITH I CAP 22   RX  II CL CLCL sin2

Siemenssin2

CAPACITOR APPLICATION (Δ CAPACITOR APPLICATION

  I C Loss ReductionDueto L V (ANGLE (ANGLE L

CL TTS LOSS MAXIMIZED WHEN: I WHEN: MAXIMIZED LOSS TTS 2     Θ LOAD L  IS POSITIVEFOR 22  I L IIRI CL

IIIIRIIII 0.12 CLCL W) REACTIVE CURRENT 0.12 LAGING PFLOADS) L 2   C L 2 = I C 2    I LOAD  L RPF SIN( RIPF I LINE

θ I L CAP

) ACTIVE CURRENTACTIVE O

Current Phasors With Cap-Detail.FCW O L 29

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 ( LOSSES WITHOUTCAPACITOR IN LINEPERUNITOF REDUCTION INI Siemens Power Transmission & Distribution, Inc., Power Technologies International Δ Capacitor Application (continued) Lumped LoadCase– 2 REDUCTION IN I R LOSSES IN PU OF ORIGINAL W/W) 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0 0 CAPACITOR CURRENT IN PER UNIT OF LOAD CURRENT I CURRENT LOAD OF UNIT PER IN CURRENT CAPACITOR 2 R LOSSES 0.2 P F L

0 0.4 . 9

5 Siemens P F L P

= Loss ReductionDueto F

0 L

. = 9 P

0 0 0.6 F

. 8 L

5 =

SUBSTATION Voltage Drop Basic-1.FCW Voltage 0 . 8 0 V S 0.8 FEEDER I L 1.0 RX PEAK  W W I I I PEAK C C L  V W W L 1 I I  C L 1 OCCURS PF   W W 12 L LOAD 2 L PF 2 IS I L PUPF L 2 : WHEN      I I C L     : 2 30

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 WATTS LOSS PER PHASEIN1MI LOSSPER WATTS WATTS LOSS PERPHASE IN LINE LENGTH=1.0MILE CAPACITOR BANK NOMINALCURRENT(1200 KVA3- Siemens Power Transmission & Distribution, Inc., Power Technologies International Capacitor Application,Example, 477KCMILPHASE Lumped LoadCase, W I CAP P - TO -P P -TO 13.8 KV L 2  CAPWITH RIW  3 KVA       KV C 2  2 CL  22 1 MILE  1200  2  IIII 1MILE LINE WHENCAPACITORBANK ISAPPLIED CL 8.133 Power 255,24198.0*350Siemens KVAR 1200  LE LINEWITHOUT CAPACITOR 0.1 2 WATTS  2.50 AMPS L 2 Loss ReductionDueTo    80 % PF 350 AMP LOAD LUMPED RPF / 

 2    Φ )  CONSTRUCTION ARMLESS 13KV EDISON CON R =477MCM AL WIRE PHASE DISC: PTICourse,Unit8,D#1,ConEdOHDistLine O 579,20198.0*8.00.12.50*350*22.50350 = 0.198 Ohms mile =0.198 / WATTS /  - osCalc.FCW Loss 31

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Capacitor Application,Example, 477KCMIL Lumped LoadCase, TOTAL THREE-PHASE REDUCTIONINWATTS LOSSESPERMILE ANNUAL ENERGY LOSSREDUCTIONIN REDUCTION IN WATTS LOSS PERMILE REDUCTION INWATTS P - TO -P P -TO 13.8 KV  W KWHr ASSUMING $6 /KVAC, 1200KVAR ANNUAL SAVINGS ASSUMING $0.0 3    PHASE       = 11.03KW * IIW CL

1 MILE  0.12 W  Power 8760HOURS =96,623KWHR /YEAR SiemensL KVAR 1200  675,3*3*3 2 C 22    Loss ReductionDueTo  WATTS RIPF

80 % PF 350 AMP LOAD LUMPED KWHR ASSUMINGCONSTANTLOAD KWHR PER PHASEFROMCAPACITORAPPLICATION FIXED BANKCOST IS $7200.00 5/KWHR = $4831 PERYEAR 2     03.11  kW 675,3198.02.508.00.12.50*350*2 CONSTRUCTION ARMLESS 13KV EDISON CON Φ R =477MCM AL WIRE PHASE WATTS DISC: PTICourse,Unit8,D#1,ConEdOHDistLine O (continued) = 0.198 Ohms mile =0.198 /

/  - osCalc.FCW Loss 32

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Total Power(Watt)Loss InFeeder Uniformly Distributed LoadCase dP(x) = DIFFERENTIAL POWER LOSS INSECTIONdx LOSS POWER dP(x) =DIFFERENTIAL RE r =FEEDER LOAD CURRENT Uniformly Loaded Feeder-1.FCW Uniformly MAGNITUDE Source I Source SISTANCE PER UNIT OFLENGTH PERUNIT SISTANCE )(  V 0 S X 2 X SiemensX  IdxrIxdP Source 2 Distance from sourceend from Distance dx     I X FEEDER = I 21 Source L X L AT DISTANCE X DUE TO LOAD CURRENT LOAD XDUETO DISTANCE AT  ( 1 - 1 -

X L 2 2 X     L ) dxr End L X 33

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Lumped loadattheendoffeeder Incremental Power Loss-Lumped Load.FCW Loss-Lumped Power Incremental Siemens Power Transmission & Distribution, Inc., Power Technologies International INCREMENTAL Lumped LoadandUniformly DistributedLoad Graphical Comparisonof TotalPowerLosses INCREMENTAL Same loaduniformly distributedalongthefeeder Incremental Power Loss-Uniformly Dist Load.FCW Dist Loss-Uniformly Power Incremental LOSSES IN LOSSES IN WATTS WATTS WATTS WATTS dP(X) dP(X) 0 0 LUMPED LOAD AT FEEDER END FEEDER AT LOAD LUMPED 1/3 OF AREA WITH THE THE AREA WITH OF 1/3 SHADED AREA IS SHADED AREA SHADED AREA REPRESENTS THE TOTAL LOSSES DUE TODUE THE TOTAL LOADCURRENT DISTANCE FROMDISTANCE SOURCEEND DISTANCE FROM SOURCE END Siemens )0(  SOURCE 2 dxrIdP )(  IxdP SOURCE 2     L L 21 X L  X X X L 2 2

    )( dxr  SOURCE 2 dxrIxdP 34

know thecurrentineachsection section andsummingtheresults. Total lossescanbedetermined by

I 1 kW I 2 Siemens kW I 3 L kW Nothardbutoneneedsto calculatingthelosses for each I 4 kW I 5 kW I 6 kW 35

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010  Siemens Power Transmission & Distribution, Inc., Power Technologies International (continued) Assuming aUniformly DistributedLoad losses canbemadewith thefollowingdiagram. many sectionsrequired, an approximation ofthekW Without knowingthecurrent ineachsection, orhow . . . .

Losses inkW =(I)²(RL/3) Use thetotalsendingcurrent. Then, Use theresistance(R)perunit lengthofthemainline three phase. Determine thelengthof mainline

R=? 1/3 L Siemens kW 36

I 1 L1 1 2 (R)(L kW

Siemens 1 ) +I I 2 1/3L2 2 2 (R)(L kW kW 2 /3) L2 kW kW kW 37

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Assuming aUniformly DistributedLoad calculations. But youmustusecaution whenmakingthese losses. screening circuits foramore accurate reviewofthe This method canprovetobeareasonable methodfor . . .

It canonlyget youanapproximateresult very lumpy Most distributioncircuitloads are circuit length. The circuitconductormay not be

Siemens thesametypeforwhole not uniform.Infacttheycan be 38

distance values Divide thecircuitintoareas based uponmaximumloador This isjustoneway,thereare otherways per section Use theuniformly distributedloadtechnique toestimatelosses • • • • •

Sum the sectionlosses Determine the average “r” Scale connected loadbasedupon Lump theload at theend. distance ofthree thousandfeet For exampleonemegawattof maximumconnectedloadora

Siemens value Dothisforeach section

mputers andloadreadings, the readings atthestation. thereadings 39

it isstillanapproximation! This willbealittlemoreaccurat I 1

kW1 Siemens I 2 L2/3 m ofwhatIjustdid. kW 2 L3/3 I 3 e thanthepreviousmethods but kW 3 I 4 L4/3 kW4 L5/3 I 5 kW 5 40

I I I I I 5 4 3 2 1 2 2 2 2 2 x R x R x R x R x R

5 4 3 2 1

x (L x (L x (L x (L x L 1 2 5 4 3 /3) /3) /3) /3)

Siemens     kilo-feet (kft) in lengthbuttheunitsare in The linesectionsarenotequal section basedupon average ofthetypesin The resistanceistheweighted Units areohms perunitlength contribution to thelength. constant. The powerfactor isassumed

Siemens

© 2010 Siemens Energy, Inc. All rights reserved  . Siemens Power Transmission & Distribution, Inc., Power Technologies International Calculation ofElectric SystemLosses… Power nrykhEeg W nrykWh Energy kWh Energy kWh Energy . system balanceequations: The calculationsarebased onthepowerandenergy For power, Similarly, for Energy:

input input )( () () () kW )(   Siemens Power output output kW )(   Power losses losses kW )( 2 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International …Calculation ofElectric SystemLosses… Third, determine for the same period,thetotalenergydeliver Third, determineforthesame fromallsources the studyarea Second, determineforaperiod definetheareaofstudy First, normally, acombinationof: Find the difference between the twonu meteringpoints through theknowncustomer . . . . .

Energy Diversion (theft) – Diversion(theft) Energy Reading errors – Data from inaccurate meters– unmetered loads need to beestimated Unmetered loads– Unmetered System losses–

which iswhat which canbeminimized by which which shou

Siemens

which canbe which the loss study the lossstudy be minimized by re-c by can beminimized which of time, usuallyayear,thetotalenergy flowinginto ld beknownandcan bees

minimized withadequate supervision mbers found above. The difference is, optical reading andco needs tofind timated. Losses causedby alibration ofmeters alibration ed mputerized recording to allcustomers

3 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International …Calculation ofElectric SystemLosses… Losses inthe Secondary Distributionsystem include: performed for: Load andno-loadlossesare calc ......

Secondary Distribution System Secondary Distribution Primary Distribution System Transmission to Distribution transformers Transmission system transformer GSU transformers– Customer Meters Distribution transformers Service Drops Secondary lines

Siemens if plantmeter if

ulated Thecalculationsare is onlowvoltagesideofGSU 4 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International …Calculation ofElectric SystemLosses… circuits usingregressioncurve techniques number ofcircuits,andapply there them. Onemethodistocalculate virtually impossibletocalculate thelossesineachandeveryone of Due tothevastnumberof primary the loadofmost distributiontran many companies, transformerda The numberofdistribution transforme can beestimated orloadingassumptions canbemade. can berecorded. Theloadoftransformersthat arenotmonitored applied toallservice dropsinthe group of servicedrops withtypical designs. Then,theresults canbe losses inservicedrop of calculation The numberof servicedropsmayb

Siemens ta management systemsmonitor sformers. Peak loadsorhourly system usingregression techniques in detail thelossesinaselected in detail andsecondarycircuits,itis e verylarge.Therefore, the s canbe performedfor aselected sults tothewholepopulation of rs is,typically,verylarge.In loads

5 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International …Calculation ofElectric SystemLosses the lossresults allocated for thelossstudyand desired accuracyof calculations isatradeoffbetween thebudgetandtime The numberofcircuits tobeconsideredforthedetailed results willbe drops thatarecalculated indetail,themoreaccurate The higherthenumber ofprimarycircuitsorservice

Siemens 6 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International General Methodology… readily available, usually any un-metered use. Thiscalc and subtracting the salesand inter-tie flow “in” data bytaking allinputstotheelectric system, including Total electric losses canbedetermined from metered Form 1(AnnualReport ofMajorElectricUtilities) report theirannualenergy lossesonpage401aofFERC In theUnitedStates,power companiesarerequiredto electric rates Demand andenergylosses areusedinthedesignof

Siemens and thesystem internalgeneration,

ulation requiresdata thatis inter-tie flow“out”, plus inter-tie 7 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010      Siemens Power Transmission & Distribution, Inc., Power Technologies International …General Methodology Metered Energy Losses(kWh)=Input - use Output (kWh)=Sales+ Inter- purchases (internaland external) generation + Input (kWh)=Inter-tie flowsin+internal For outputs, not always recordsusuallyexist For inputs, good hourlyaccounting

Siemens accounting records exist accounting tie flowsout+un-metered Output

8 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010       Siemens Power Transmission & Distribution, Inc., Power Technologies International Outputs Customer salesareusually the largestcomponentofoutput use etc.). (street lights,trafficsignals, cons Output alsoincludesmeter co countries. Itcan beestimated verysmallinUnitedStates andmany Energy diversion istypically Consumption ofnon-metered ou bases. Datais recordedonamonthly schedule Small customer classeshavetheirmeters usuallyreadonamonthly every month readings aretakenthroughout th Meter reading timing issuesusually arisedueto thefactthat

Siemens mpany useandnon-metered use tput isnormallyestimated umption ofsomebuildings, station e month andnotat the endof 9 Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International General Methodology energy losses ofeachsub- a differentapproach isused),for the calculationof With theexception ofthetran the corresponding non-coincident powerdemandlosses Energy lossesaredetermined foreachsub-systemfrom each sub-system Non-coincident power demandlossesarecalculatedfor determine thetotalsystem losses Energy lossesfor all sub-systems areadded upto method isused

Siemens system, the “lossfactor” smission system (forwhich

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International Metered vs.Calculated EnergyLosses the extent thisispossible.Lossescan alsobecalculated the extent to Losses ineverysub-system canbedeterminedfrommetereddata, calculated shouldbeevaluated calculated metered lossesforthatsub-sy Calculated EnergyLossesfor eachsub-systemarecomparedtothe Loss multipliers areused inelectric ratedesign a unitofpower orenergyat how muchpower orenergyisrequ Demand and Energy LossMultipliersare calculated.Multipliersshow

Siemens thecustomer servicelevel stem. Anydifferencebetween ired atthesupply leveltodeliver 11

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Demand andEnergy Loss Multipliers… kWh to covertheone kWhand theenergylosses energy, thegeneration system wouldhave toprovide1.06 level means that ifaresidentialcustomer requiredonekWhof For example, anenergymultiplierof 1.06attheresidential energy Each customerlevelhas a differentmultiplierfordemandand service level supply leveltodeliverone kWoronekWhateverycustomer Multipliers showhowmuch powerorenergyisrequiredatthe

Siemens 12

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International … Demand andEnergy LossMultipliers… Demand … system losses onthesubstation sy Substation customers areresp transmission system share oflosses thatresultfrom their serviceonthe Transmission customersare demand losses provide 1.08kWtocover demand ofonekW,the generationsystemwouldhaveto level meansthatifaresidential customerplaceda Similarly, ademandmultiplier

Siemens the onekWloadand stem and thetransmission only responsible fortheir onsible oftheirshare of of 1.08attheresidential 13

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International … Demand andEnergy LossMultipliers Demand … load creates onallfoursystems Secondary customers are respon substation systemand resulting fromtheirload ontheprimarysystem, Primary service customers

Siemens the transmissionsystem are responsibleforlosses sible forlossesthattheir 14

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Loss Multipliers kWh) atthe respective servicelevel generation is required toserve oneunitof energy(kWor Demand orenergymultipliers specifyhowmuch confusion Referring tolossmultipliers aslossfactorsmayleadto Loss Multipliersaresometimes calledLossFactors. . . .

Transmission Primary Secondary

Siemens 15

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010       Siemens Power Transmission & Distribution, Inc., Power Technologies International Example ofMultipliers Transmission Primary Secondary Total-secondary-primary-transmission Energy/demand Loss multipliersbyservice level

Siemens 16

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International  Energy LossMultipliers Sector Loss Multiplier 786,793 kWH Losses: Total Generation Purchases Native Native Energy Multipliers Input: +

System Input 14,987,617 Transmission Transmission Transformers 230,950 Losses: Transmission 431,794 Lines 1.0157 Sales Siemens& 14,324,873 Transmission Transmission Substations Substation 128,278 Losses: Primary Primary 531,563 1.0090 Sales To 13,665,032 Distribution Distribution 161,331 Losses: 1,835,946 Primary System Primary 1.0119 Sales 11,667,756 Distribution Distribution 11,401,521 1.0234 Secondary Secondary Diversion: 266,234 System Losses Sales + 17

Siemens SalesSector  SalesSector  LossSector Output  Output 18

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Calculation ofEnergy LossMultipliers Calculated Data Multiplier LossEnergy System -k Output kWh - Sales kWh - Losses System kWh - Input Cumulative Sector W Transformers Cumulative & Lines Transmission 14,324,873 497671,2,7 3650211,667,755 13,665,032 14,324,873 14,987,617 3,5 3,5 2,7 5,2 6,3 2,5 6,3 786,793 266,234 14,200,824 11,401,521 520,559 2,799,303 1,835,946 161,331 963,357 359,228 531,563 128,278 431,794 230,950 431,794 230,950 1.0157 1.0157

Siemens Multipliers Loss Energy usain Cumulative Substations Primaryto Transmission 13,665,032 1.0246 1.0090 ytmCumulative System Primary Distribution 11,667,755 1.0360 1.0119 ytmTotals System Secondary Distribution 1.0554 1.0234 0 19

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010  Siemens Power Transmission & Distribution, Inc., Power Technologies International Type ofCustomers… requirements system dependingon the customerdemand Power companiesconnect theircustomerstotheelectric • •

small industrial innature distribution primary systemandarenormally commercialand Intermediate demand customersareconnected tothe customers or requirement salescustomers transmission systemandare consideredindustrialclass Large demandcustomersare connecteddirectlytothe

Siemens 20

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International …Type ofCustomers • • utilities, municipalities, cities,cooperatives, etc. are,other supplier orutilitycompany.Examples planning ofthe and theirenergy needsareincl Requirement salescustomers requir Requirement SalesCustomers purchaseenergyforre-sale. the distributionsecondary system Smaller commercialandresidential customersareconnectedto

Siemens uded inthesystem resource e energyonanongoingbasis 21

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Where aretheelectriclosses?... transformers, etc transformers, current grounding Equipment includes,customer meters,potential power equipmentatall voltagelevels Losses occurintransmission

Siemens lines,transformersand 22

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010          Siemens Power Transmission & Distribution, Inc., Power Technologies International Other equipmentwith losses FACTS DEVICES Filters Line Regulators Condensers Synchronous AC-DC-AC Back toBack DC Lines DC Terminals Capacitors Reactors

Siemens 23

13.8 kV to120/240 volts 69 kVto13.8 kV 230 kVto13.8 kV 500 kVto230 kV 230 kVto115 13.8 kVto115 22 kVto230

Siemens 24

Source P 1 = E E I

1 1 1 I

1 Mutual Flux

• N a b Siemens1 Magnetic Core • d N c 2 P 2 = E I 2 2 I

2 E2

Load 25

E I

1 1

1 leak

Mutual Flux Siemens 1 leak Magnetic Core M

2 leak

2 leak I 2

Load 26

LEAKAGE (WINDING LOSS OR LOAD LOSS) LOAD LOSSOR (WINDING LEAKAGE E 3 I m I L MAGNETIZING R s X s Load 27

Siemens h  W e 28

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Transformer Voltage a FunctionofFlux ore lcia D Reference Book T& Electical Source: n Where: E E B A f = = Frequency 2 max s s Magnetic CircuitArea = TurnsinWinding = Winding rms InducedVoltage =  Maximum Flux Density = 2  2 f nAB

Siemens 2 max 10  8 29

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Transformer No-Load Loss ore lcia D Reference Boo T& Electical Source: t WKBftWKBf Where: KK 2 Thickness ofSteelLaminations = ee h hh x Steel Quality Factors = ,x , Note: Losses –   e max 222 max x

Watts/pound Siemens

k 30

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010      Siemens Power Transmission & Distribution, Inc., Power Technologies International Iron LossesaFunction ofV Iron lossat100percent voltage Calculated voltage function Iron lossat110percent voltage Recommend use square function Use transformer specific, or    

125,200 watts 90,290 wattssource(from manufacturer’stestreport) (125,200/90,290) =(1.1/1.0) X =3.4

Siemens x 31

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Transformer Losses Losses Watts 100,000 200,000 300,000 400,000 500,000 600,000 700,000 0 04 08 0 2 4 6 8 200 180 160 140 120 100 80 60 40 20 0 230/115 kV, 150, 200, 250, 280 MVA Transformer No-Load Load Losses & Minimum Load

Siemens Percent Loading Percent 32

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010  120/240 volts 34.5/13.8 kV 115/13.8 kV 230/115 kV 500/230 kV Generator step-up Siemens Power Transmission & Distribution, Inc., Power Technologies International Approximate IronLoss the manufacturer foractualvalues. The abovevalues arenotastatistical collection,check

Siemens

.00228 pu .00100 pu .00046 pu .00148 pu .00138 pu .00156 pu 33

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Load andNo-LoadLosses… Load lossesdependon theloadlevel any electrical load No-Load lossesexisteven if the circuitisnotsupplying      

vary much) No-load lossesmaybe assumedcons No-load losses dependonth losses In transformers, no-loadlossesare Occur inallsystemcomponents inthecircuit flowing squareofthe current Depend onthe as“copperlosses” Also known

Siemens e voltageofthe circuit (lines,transformers,etc.) also known as“iron” also known tant (as longvoltages don’t or “core”

Understanding System Losses

© 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010  Siemens Power Transmission & Distribution, Inc., Power Technologies International …Load andNo-LoadLosses… Load losses- . . . . .

Losses willfall if thecrosssectional capacity the leveloflosses onanetworkwillbe betweenlo Due totheproportionality arevariable networks distribution Usually, between2/3and3/4 of thetechnical(orphysical)losseson cables, butalsointhecopperparts oftransformers They areoftenreferredtoascopper utilization rates are not, of losses initsdesigncould beas onadistribu average utilizationrate costof between There is atrade-off load isincreased

they arevariablein Siemens probably, economical nature because depend on the load dependon nature because low as30 percent;however, area oflinesand cables tion network that considers the cost thatconsiders tion network losses and cost of capital. Optimal losses and costofcapital. Optimal losses, occurmainlyinlinesand sses andthesquare ofthecurrent, affectedbythe utilizationofits for agiven those low

networks are fixed Typically, between1/4 and1/3of voltage isrelatively constant Fixed losses varywithvoltage, bu transformer is energized of heatandnoise ontransfor Fixed lossesdo notvary other fixedlosses,likecustomer meterlosses) losses) anddonotvaryaccording to current(notethatthereare cores (thus,also called iron Occur mainlyinthetransformer

Siemens accordingto current. Theytaketheform mers andoccur aslonga t arerelatively constantifthe technical losses on distribution technical lossesondistribution 36

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Transformer Auxiliary Loss Transformers ratingOA/FA/FA/FOA Transformers service power.Itmayor not bemetered. service Auxiliary load atthesubstation . . . .

FA – FA – FA OA – FOA –

Oil toForcedAir(provided by secondgroupoffans) Oil toForcedAir(provid Oil toAirnaturalconvection Forced oiltoAirnaturalco

Siemens ed by first group of fans) groupof first by ed nvection (oil pumpsareused) ispartofthe substation 37

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International GSU Losses… efficiency andarenotpart in theelectricratedesignprocedure losses thathavehighsidemetering transformers (lowvoltageside of ifthemeters arelocatedonthegeneratorsideof only calculated The lossesinthestep-uptransforme described above forotherclassesoftransformers typical data.No-load lossesaredetermined inthesamemanneras Load andno-loadlossesare calculatedusingmanufacturer’sdataor energy losses (kW). The hourly transformer lossesaresummed todetermine the load loss data,thehourly transformer loadlosses canbedetermined hourly loadsandth e transformer resistance orrated loads. From the Hourly plantoutputs areusedto

Siemens determine the hourlytransformer theGSUtransformer).Transformer areconsideredpartofthe plant rs atpowerplantsneedto be 38

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International …GSU Losses… calculation GSUlosses of the GS thegeneratorssupplying of Generating type,modeofoperatio Load shapesof GSUtransforme Generator typesandmodes ofoperationare,typically, Planned and forced outages Planned andforced . . . 

Base, fullloadwhen inservice Intermediate, load following Peaking, load following fewhours Results inzero ornull loads

Siemens making loss factorinaccurate shoulders, full loadpeak shoulders, r areafunction oftheabove n andplannedforcedoutages U transformersareusedin the

Siemens Base loaded Hours Intermediate loaded Intermediate Peaking 40

throughout theyear, theironlosses arerelatively constant Assuming thattheoperating volt No-load losses varywiththesq present whenever thetransformerisenergized No-load losses areintheformofheatenergy andnoiseare currents transformer andarecaused bytheexcitationandmagnetizing “Iron Losses”.No-loadlosses arelossesintheironcoreof No-load lossescomponent, inWa

Siemens No LoadLosses

ormers havetwocomponents: uare oftheapplied voltage. age remains relatively constant tts, sometimes referred toas 41

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Transformer Losses– during theyear ofstudymustbe obtained inventory entire transformer To calculatethetotaltransformer losses,dataforthe electric currentflowingthrough thetransformer as “copperlosses”.Load lossesvarywiththesquareof Load Lossescomponent, inWatts,sometimesreferred to

Siemens Load Losses

of allunits in operation 42

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010  Siemens Power Transmission & Distribution, Inc., Power Technologies International Transformer Data contains, atleast,thefollowing: manufacturer provides the testreport datawhich and manufacturer. Forevery transformer, the Transformers areclassified bysize,yearofmanufacturer • • • • •

Load losses,in Wattsorper No-load losses, inWattsorperunit,atrated voltage Impedance, in Ohmsorperunit Rated voltage, primaryandsecondary Size, kVA

Siemens unit, atrated load conditions 43

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Transformer Losses… losses (kW) can becalculated estimated forevery transforme Once the non-coincident demand (kW) isdetermined or and yearof manufacture isuseful transformers. Inthesecases usually can beestimatedusingdata fromsimilarlysized Information fortransformerswi from thetransformersize available, thenon-coincident determined usingmetered loaddata.Ifdataisnot without load,thenon-coincident demand,inkW,canbe For everytransformer that isenergized,withloador

Siemens , knowingthe manufacturer demandcanbeestimated r, the corresponding load th nomanufacturer’s data 44

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International …Transformer Losses (transmission, distribution, etc.) particular sub-systemwhere thetransformerislocated factors calculatedfromload researchormetereddataforthe Energy loadlosses(kWh)can bede by themanufacturer Demand no-loadlosses,in Watts, foreverytransformerisprovided transformer is energized multiplying the demandno-loadlo Energy no-load lossesforeverytransformer areobtainedby corresponding losses in respective sub-systems arecalculated bysumming the Total load andno-load demandand

Siemens sses bythenumber ofhoursthe termined fromtheloadand loss energy lossesfor alltransformers 45

Be suretocheckhowthecomp overall plantefficiency lossesforthetransformerin the Many companiesincludethe Only includedifmeterison the • •

Load orcopper losses No-load, iron,or excitationlosses

Siemens any accountsforthese losses generator sideofthetransformer 46

Calculate energylossafunction Calculate demandloss operation hoursof Determine Determine loadlossfrom manufacturer Sum losses ofallGSU transformers • • •

Peaking Intermediate Base

Siemens oftype/outputcharacteristic 47

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010        Siemens Power Transmission & Distribution, Inc., Power Technologies International Procedure forCalculation ofTransformerNo-LoadLoss… Determine no-loadlossfrom manufacturer Determine iftransformeris off Determine hours of operation hoursof Determine Determine voltage magnitudeschedule Adjust lossafunction ofsquarevoltage Calculate demandloss Calculate energyloss

Siemens when generatorisoutofservice 48

Determine energy loss Determine demandloss Apply voltagecorrectionfactor Obtain no-loadlossfrommanufacturer or estimate Inventory byvoltageandsize

Siemens 49

Wheeling Loop flow Schedules with neighbors Generation Load Rain Voltage

Siemens 50

Single phasetoneutral Two phase Three phase

Siemens 51

Siemens Power Transmission & Distribution, Inc., Power Technologies International Dc ResistanceofOne Wire  Conductor Radius = a r r dc dc Resistivityat a SpecificTemperature =

 

DCResistanceof a Conductor   * 1 a

Siemens2 53

Siemens 54

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Resistivity asaFunction ofTemperature t α Where, ρ In general,theresistivity, ρ ρ t =Actual temperature oftheconductor ρ 1 t1 = = Resistance temperatureco = Temperature referenceforwhichthe referenceresistivity, = Resistivity at anactual temperature, t = Resistivity atreference temperature, t ρ ρ

*[1+

, isgiven

α *(t-t 1 Siemens )]

, ofaconductorisgiven by: efficient for the conductor 1 55

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010          Siemens Power Transmission & Distribution, Inc., Power Technologies International Conductor Characteristics Dc resistance @20° Conductor diameter– Strand diameter– Stranding – Name – Ampacity AC resistance @50° AC resistance @25° Size –

556.5 kcmil dahlia

@ 75°

c – c Siemens 0.1711 inch AAC

c – c 703 703 c – c – c

0.856 inch

.60 Ohms/mile 0.1640

.85 Ohms/mile Ohms/mile 0.1855 0.1691

amps 56

Temperature Length ofcatenary Skin effect Stranding increases Speed of thewind– Temperature of surroundingair Current (load)

Siemens temperature temperature

decreases whenthe windspeed 57

Ohms/Mile 0.0000 0.1000 0.2000 0.3000 0.4000 0.5000 0.6000 0.7000 0.8000 0.9000 1.0000 .00020 .00060 .00100 .00140 .00180 2.0000 1.8000 1.6000 1.4000 1.2000 1.0000 0.8000 0.6000 0.4000 0.2000 0.0000

Siemens 115 kV Resistance Conductor Area (Square Inches) (Square Area Conductor 115 kV Reactance 58

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International ACSR ConductorResistance leid25 .47001 .550.33% 0.38% 0.0555 0.37% 0.38% 0.0903 0.0516 0.39% 0.0769 0.39% 0.1390 0.0832 0.0477 0.1102 0.0709 0.39% 0.39% 0.1719 0.1278 0.0759 0.1013 0.0649 0.2288 0.39% 2156 0.1963 0.1579 0.1166 0.0921 0.2100 1272 0.39% 0.1802 0.2743 1510.5 0.1439 0.39% Bluebird 0.1913 0.1642 1033.5 0.2518 0.3240 795 0.93% 0.74% Nuthatch 0.4083 636 0.2294 0.2974 Bittern 0.6280 0.9320 556.5 477 0.3748 Ortolan 0.2708 0.5730 0.8430 Drake 397.5 0.3413 Scoter 0.4290 0.6810 336.5 Eagle 266.8 Hen Lark 4/0 2/0 Oriole Junco Penguin Quail Conductor Name kcmil Siemens Size R@25°C R@25°C Ohms R@50°C R@50°C Ohms R@75°C R@75°C Ohms Increase Degree Per Per 59

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International AAC ConductorResistance aers 20008 .59005 0.31% 0.35% 0.0556 0.36% 0.0778 0.37% 0.0519 0.39% 0.0912 0.0720 0.1107 0.0482 0.1771 0.0841 0.39% 0.39% 0.0663 0.1020 0.1311 0.0772 0.39% 2250 0.2352 0.2020 0.39% 0.0934 1510.5 0.1485 0.2817 0.2159 0.39% 0.1855 Sagebrush 0.3325 1272 0.40% 1033.5 Galdious 0.2586 0.1968 0.1691 0.4188 0.3052 636 Narcussus 0.8384 0.2355 Larkspur 0.3843 0.2779 556.5 0.7692 477 Lilac 0.3499 397.5 Orchid 336.5 0.7000 Misteltoe 266.8 Syringa Canna 2/0 Tulip Laurel Oxlip Aster Conductor Name kcmil Size Size 9 .17011 .450.38% 0.1425 0.1311 0.1197 795 / .47044 .270.39% Siemens 0.5277 0.4842 0.4407 4/0 R@25°C R@25°C Ohms R@50°C R@50°C Ohms R@75°C R@75°C Ohms Increase Degree Per Per 60

Temperature Centigrade 100.0 110.0 120.0 40.0 50.0 60.0 70.0 80.0 90.0 0 0 0 0 0010 1400 1200 1000 800 600 400 200 0

Siemens Current Amps Current Wind 2 Ft/Sec 2 Wind Drake ACSR kcmil 795 @40°C Ambient Wind 6 Ft/Sec 6 Wind Wind 10Ft/Sec Wind 61

Resistance Ohms 0.1200 0.1250 0.1300 0.1350 0.1400 0.1450 0.1500 0.1550 0.1600 0 0 0 0 0010 1400 1200 1000 800 600 400 200 0

Siemens Wind 2 Ft/Sec 2 Wind Current Amps Current Drake 795 kcmil ACSR @40°C Ambient Wind 6Ft/Sec Wind 10Ft/Sec 62

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Resistance andTemperature Resistance (ohms/mile) 0.1600 0.1650 0.1700 0.1750 0.1800 0.1850 0.1900 0.1950 0.2000 0.2050 03 05 07 80 70 60 50 40 30 20

Siemens Temperature C Temperature Dahlia 556.6 kcmil 63

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Probability DensityFunction 100 10 20 30 40 50 60 70 80 90 0 0 0010 0020 3000 2500 2000 1500 1000 500 0 assumptions) weathercase" (based on "worst Rating Static 920 amp (1 Year of Data, Drake Conductor) Drake Yearof Data, (1 Siemens Line Rating Distribution Line Rating (amps)Line over 1 year over 1 Actual Ratings 64

Distribution lines Transmission lines • • • • • •

Rerun power flow withadjusted resistances Rerun power Adjust resistance asafunction ofcurrent at75° Run power flowusing resistances flowwithadjustedresistances Rerun power Adjust resistance asafunctionofcurrent at25° Run powerflowusingresistances

Siemens usuallyprovided at75° c c

c c

Calculate temperature/resistan Select windspeed,ambient temp. Maximum conductortemperature Conductor resistanceatspecific temperature

Siemens ce forwind/ambient/current 66

Siemens 67

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International …Transmission System Losses… conditions are represented inpower flowcases. going tobe.Typically, between 20and 30system the more accuratethe transmission losscalculation is the year beingstudied. The more casesare considered, representative ofsystemconditions that occurred during flows. These differentsystemconditions shouldbe andtie of systemconditions ofload,generation dispatch Power flow casesaredevelopedrepresenting anumber the helpofapowerflow program Losses inthetransmission syst lines andtransmission transformers The transmissionsystem is

Siemens comprised oftransmission em can becalculated with 68

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010      Siemens Power Transmission & Distribution, Inc., Power Technologies International Transmission Procedure (500/345 kV, 230/115 kV) Power flowmodelingnormally incl The ideaistodeveloppower flowstocapture Normally theyarenot No-load transformer lossescanbe Make surethe resistanceismodele Integrate the curve asa function of theload duration curve . . .

Imports, exports,wheeling,andloopflow Imports, varybydayorseason as they schedules Generation Hourly load during theyear

Siemens includedinthe powerflow. udes transmissiontransformers d inthetransmission transformers 69

procedure) Load orcopperlosses(included inthetransmissionlines losses orexcitation iron, No-load,

Siemens 70

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International …Transmission System Losses… with differentgenerationschedule summer lightload,winter peak, minimumload,etc.areanalyzed, representing summerpeak,summershoulderload, Conditions flow cases these systemconditionscan bedetermined bysolvingthepower sound engineeringjudgment. Thetr exports. Thesecasesshould bemodeledwiththegreatestcareusing load for anyvalue of systemloadbetweenpeakand minimumsystem regression equation canbederive regression curve canbefittedto loss forevery system conditionmodeledwill be obtained.A representing thesystemloadand thetransmission Pairs ofpoints neighboring utilities function ofthesystem loadandthe transferof energy toandfrom The loss equationso derivedfor

Siemens thesepairsof pointsanda the transmission system isa d to calculate thetransmission d to s, wheeling levels,importand s, wheeling ansmission lossesforeach of loss

Losses - MW 10.0 20.0 30.0 40.0 50.0 60.0 0.0 0010 0020 003500 3000 2500 2000 1500 1000 Power Flow Flow Power Results Siemens Regression Analysis Results Analysis Regression System Demand- MW 72

Percent Losses 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 05 07 09 100 90 80 70 60 50 40

Siemens Actual SystemLosses Actual Percent Transmission Load Theoretical SystemLosses Theoretical Hypothetical SystemLosses Hypothetical 73

Curve Poin o eeainTeFo ossLse b m Losses Losses TieFlow Generation No. 417 6 13.3 13.7 13.5 465 529 628 1070 1170 1270 24 23 22 017 6 15.3 16.7 21.4 474 17.4 568 18.8 493 20.3 1369 129 26.3 1470 693 27.1 1570 636 23.3 1670 579 21 30.5 1770 188 20 29.1 1870 232 19 1970 661 18 2072 211 17 2169 460 16 2270 15 2368 14 2470 13 12 11 10 341053.7 110 3384 1 261650.3 126 3266 2 161448.5 104 3166 3 051044.8 170 3065 4 901842.4 188 2970 5 803438.2 314 2870 6 7 8 9 t 734835.5 408 2773 694333.4 413 2669 514530.1 485 2571 Siemens Are a acltdEtmtd1003 6.317448 1.000632 Estimated Calculated 14.9 53.5 49.7 12.4 13.2 14.1 15.0 46.6 43.7 41.2 38.7 36.4 34.1 16.0 17.0 18.1 19.3 20.6 21.9 23.4 24.8 26.5 28.2 30.0 32.0 1.59 1.54 1.24 1.17 1.06 1.09 1.53 1.46 1.43 1.33 1.28 1.25 1.04 1.06 1.28 0.98 1.01 1.03 1.27 1.25 1.03 1.29 1.18 1.17 74

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International …Transmission System Losses be used maximum loads. Therefore, aload duration curvehas to points with thesamevaluebetween theminimumand is notpossible becausethereare multiple loaddata A directintegration ofthelossvs. systemdemandcurve a year the hour-by-hourdemand lossesoverthe8,760hoursin calculated from theregression from theregression equation. Energylossescanbe data, thehourlytransmissi From thehourlysystemloads, availablefrom metered

Siemens on lossescanbecalculated equationbyintegrating 75

Demand (MW) 1000 1500 2000 2500 3000 3500 500 0 0020 0040 0060 008000 7000 6000 5000 4000 3000 2000 1000 0 Maximum Demand = 3384 MW 3384 = Demand Maximum Siemens Time (Hours) A verage Demand1701MW Minimum Demand= 1070 MW 76

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Transmission System LoadandLosses Load (MW) 1500 1700 1900 2100 2300 2500 2700 2900 3100 3300 3500 0 0 1010 2100 1600 1100 600 100 Transmission System Load and Losses Siemens Hours Transmission System Load Difference areTransmission Losses 77

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Transmission Losses available, typical valuesshouldbe used is thecase, theresistancemustbe addedor, ifnot transmission transformersisno In manypower flowcases,theresistance ofthe calculated separately calculation oftransmission lossesandhavetobe Therefore, no-loadlosses ar losses ofthetransmission Most powerflowcases don’thavetheno-loadoriron

Siemens transformers represented. e not includedinthe t properlymodeled. Ifthis 78

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010  Siemens Power Transmission & Distribution, Inc., Power Technologies International Corona Losses principally afunctionof: Theamount weather conditions. voltages 69-kVandbelow. Itisalsosmallduringfair an energizedconductor. Coronalossisnegligiblefor Corona lossisanelectricdischarge totheairsurrounding • • • • • • • •

substantially) Adverse weatherconditions (rain increases the coronaloss Presence ofshieldwire Elevation Conductor spacing Length ofthe circuit Conductor bundling Diameter ofthe conductor Voltage level

Siemens of corona discharge is is discharge corona of 79

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International Procedure forCalculation ofCoronaLosses Determine the coronalossbyvoltage Determine hoursofrain Sum losses losses arenotsignificantfor lo (corona andabove 11kV transmissionlines of Prepare Inventory • • • • • •

Conductor sizes Conductor Voltage Adverse weather Normal weather size Conductor Voltage

Siemens wer voltagetransmissionlines) 80

Altitude Length ofline Weather conditions Spacing andclearance smoothness Conductor Conductor bundling Conductor diameter Voltage

Siemens 81

Siemens 300 Voltage kV Voltage 400 500 600 700 800 82

Losses kW/Mile 100.000 150.000 200.000 250.000 300.000 350.000 400.000 50.000 0.000 0 0 0 0 0 0 0 800 700 600 500 400 300 200 100 0 Rain 0.25In/Hr Rain Drake at230kV

Siemens Voltage kV Voltage 83

SiemensDrake at230 kV 0.4 Rain in/hr 0.6 0.8 1 1.2 84

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Siemens Power Transmission & Distribution, Inc., Power Technologies International Load DurationCurve Per Unit Load 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0 1 ...... 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 Load Factor 0.582 Loss Factor 0.365

Per UnitPer Cumulative Time (One Year) Siemens 85

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Transmission Transformer No-LoadLosses year number ofhours thetransformer isinoperation in the the no-load demand lossfor thetransformer bythe (kWh)losses No-load energy be used If manufacturer’s dataisnotavailable,typical datashould the manufacturer inventory andactualtransformer testresultsprovided by are calculatedusingthe datafromthetransformer losses (kW)intransmissiontransformers No-load demand

Siemens are obtained bymultiplying 86

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Non-Coincident Non-Coincident Coincident Peak Energy Losses Siemens Power Transmission & Distribution, Inc., Power Technologies International Transmission LossesSummary Peak (kW) (kW) (kWh) Load Losses 179,706,861 58,722 57,756 Transmission Lines 2,896,493

SiemensCorona 153 153 Losses 5,543,466 Load 2,489 2,489 Losses Transformers 34,461,595 No-Load 4,699 4,699 Losses Load Losses 185,250,327 61,211 60,245 Totals 37,358,088 No-Load 4,852 4,852 Losses 87

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Distribution PrimaryTransformer Losses… of hours inthe year the individual transformer no-load losses bythenumber No-load energylosses (kWh) areobtained bymultiplying transformer testresults,ifavailable transformer inventorydataandby applyingactual loss(kW)iscalculated usingthe No-load demand some systems transmission voltagesuch as69kVoreven34.5 in kV, 230161138 kVor115kV, asub- high-side voltageisatransmi side voltagessuchas25.0 kV low- Distribution primarytransformers havedistribution

Siemens , 13.8 kV or4.16kV. The , 13.8kV ssion voltage,suchas 345

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International …Distribution Primary TransformerLosses… obtained from loadresearch data Coincident factors foreverysubsystem areusually non-coincident peakbythecoincident factor unit. Thecoincidentpeak iscalculatedbymultiplyingthe the knowledgeofnon-coincident peakloadofeach Calculation ofloadlosses ineachtransformer requires Typical dataisusedifmanufa

Siemens cturer’s dataisnotavailable 89

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International …Distribution Primary TransformerLosses factor/loss factor method Energy load losses(kWh)are resistance data Copper (or load)losses(kW) arecalculatedfromloadand transformer at75°C Transformer testresults pr

Siemens ovide theresistanceof the calculated using theload 90

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Distribution Substation Transformers Load orcopperlosses No-load, iron,orexcitation losses Distribution substation transformers

Siemens 91

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010      Siemens Power Transmission & Distribution, Inc., Power Technologies International Procedures Determine energyloss Determine demand loss Apply voltage correctionfactor, ifneeded the dataisnotavailable Obtain theno-loadloss fromma Prepare transformer inventory byvoltageandsize

Siemens nufacturer orestimate if 92

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International Losses inDistribution PrimaryLines… influence thelosses significantly Operating temperature, load,power factor, phasebalance primary circuit and modelthe primaryandlateralruns ofthedistribution nodes, location ofcapacitors,etc.,areusedto allocateload transformers, feederconductorsizes, distancesbetween Circuit maps showingthelocationof distributionsecondary materials (copperoraluminum) Feeders typicallyhavedifferent cablesizes,usingdifferent operating atdifferentprimary voltages A typicalsystem has manydistri

Siemens bution feedersorprimary lines 93

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International LossesinDistribution PrimaryLines… … of the selected primary distribution circuits distribution linesmay beused to modelthe operationof each Power flowprograms, specifically designed toworkwith Typically, 10 to15circuitsareselected fordetailedstudy studied, the more accuratetheresults willbe detailed analysis.Themore thenumberofprimarylines distribution primaryvoltages levels,iscarefullyselectedfor Therefore, asampleofprimary distributionlines,atall and everydistributionprimary circuit cases, itmaybeimpractical tocalculatethelossesforeach There maybemanydistribution

Siemens primary linesand,inmany 94

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International LossesinDistribution PrimaryLines … demand losses(kW) Distribution lineamperes,kW orkVA losses areobtained demand forthecircuit.Pairs ofre foreachselectedcirc calculated The selectedcircuitsaremodele non-coincident peak demandofthe circuit for everyprimary distributioncirc regression equation allowsthecalculation ofthedemandlosses(kW) A regressionequation isfittedtothepairs ofdemandvs.losses.The method factor factor/loss The energy lossesare calculatedus ing the load

Siemens uit usingthenon-coincident peak d anddemand(kW)losses are uit inthesystem fortheknown sults ofcircuitdemandvs. circuit load areusedindetermining load

Calculate energylosses (lossfactor) Calculate demand losses(powerflow) Include distribution secondarytransformers Model lines(statisticalsample) • • •

Include overheadandunderground systems Include differentdensities,lengths, loadlevels Include differentvoltages,13.8 kV, 4.8 kV

Siemens 96

Single phase(ground orneutral) ofload/weather Resistance afunction Two phase Three phase • •

Most popular range 11.5to13.8 kV Most popular Normal voltagesrange from2.4 to34.5 kV

Siemens 97

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010        Siemens Power Transmission & Distribution, Inc., Power Technologies International Capacitor Placement Load onsimplesystem: Switch capacitors Fixed capacitors Percent savings:13.5 % Loss savings with caps:13.53 kW Demand losses withcaps:87.00kW Demand losses w/ocaps:100.53 kW  

1,704 kVAr 3,130 kW

Siemens 98

Siemens 26.0 Percent Increase 99

8.2 Percent Increase Siemens 100

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010       Siemens Power Transmission & Distribution, Inc., Power Technologies International Procedure… Calculate demand losses Model distributionlines Select representativesample ofprimarylinesincluding, Calculate energy losses Allocate thelossesto alllines Obtain loadresearch information . . . .

Three phase,2 phase,andsinglephase and timeavailable From allavailablelines,choose astat Representative voltages Rural, city,andurbanlines

Siemens by customer classfor loads istical sampletomatchthebudget 101

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International …Procedure energy) Estimate the subsystemtotalquantity (demandand Use load/lossfactorfor energy Calculate demandlosses for servicedrops Model withpowerflow orspreadsheet

Siemens 102

Circuit Loss (KW) 100 150 200 250 300 50 0 0040 0080 00 12000 10000 8000 6000 4000 2000 0 ExponentialRegression Analysis FitData to

Siemens tion CircuitLosses Circuit Load(KW) Calculated Data 103

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010      Siemens Power Transmission & Distribution, Inc., Power Technologies International Losses inDistribution Primary voltages are usually in the 15-kVclass Primary voltagesareusually inthe Secondary voltagesuseconsumer loss components,copperand ironlosses As alltransformers,distribution secondarytransformershave two is usedtocalculate th The inventory dataofallexisting information manufacturer, manufacturer, impedance, and test reportloss usuallyincludesize, yearof Data inthetransformer inventory

Siemens Secondary Transformers… e loadandno-load losses distribution secondary transformers voltages (120V,240etc) voltages 104

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Losses inDistributionSecondaryTransformers … assumed constant overthe 8,760 hours oftheyear manufacturer’s data orty No-load lossesare calculated separately, using the loadfactor/loss factormethod Energy losses for eachtransformerare calculatedusing data coincident ordiversity factorsderived from loadresearch estimated. Coincident peak de peakdemandhastobe not known,thenon-coincident transformer isusedto calculate theloadlosses(kW).If If known,thenon-coincide

Siemens pical data. Ironlosses are nt peak demand for each for each nt peakdemand mand iscalculatedfrom 105

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International Secondary ServiceTransformers Secondary 240/120, 480/277,208/120 v SECONDARY 380volt Primary 34.5to2.4kV Distribution voltages . . .

Statistical information Load orcopper losses losses orexcitation iron, No-load, • • •

Loss characteristics Size Number

Siemens 106

Determine energy loss Determine demandloss Apply voltagecorrectionfactor Obtain no-loadlossfrommanufacturer or estimate Inventory byvoltageandsize

Siemens 107

Frequency 100 120 20 40 60 80 0 01 416 14 12 10 8 6 4 2 0

Siemens uit LoadingFrequency CircuitMVA Load 108

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International Drops… Losses inDistributionSe as aguide slightly different from thestandard, thestandards serve customer. While eachcustom kindof conductor configuration tobeused foreach the secondary servicesthat Usually, power companieshavedistribution standardfor prohibits adetailedcalculation ofallcircuits secondary andservice drop circuitconfigurations the servicedrops tothecustomer. Thesheernumberof calculation oflossesfor distribution secondarylinesand The mostuncertainand difficultcalculationisthe

Siemens condary LinesandService describethe standard er’s electric serviceis 109

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Drops… Losses inDistributionSe … system factor andload balanceonthetwo-wire andneutral Key factors influencing thelossesare cablesize,power create asecondary systemloadset data foreach Hourly research some ofthemcommercial calculate thedemand losses, Typically, asampleoftypical secondarycircuitsisusedto

Siemens condary LinesandService some ofthemresidential, customerclassisused to 110

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Drops… Losses inDistributionSe … losses (kW)canbe calculated forevery configuration from load researchdata an The customer loads modeled inthecalculation come cable sizes configurations, let’ssay,ten areperformedfora numberof calculations Typically, duetobudget andtimeconstraints, consuming andcostly istime for manydifferentcombinations which the feeders inthissubsystem wouldrequire calculations Even consideringastatistical sample,theuniquenessof

Siemens condary LinesandService d non-coincident demand configurations, withcertain 111

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Drops Losses inDistributionSe … do not occur atthe time ofthe systempeak research data, areusedtoaccount forcircuit peaksthat Diversity or coincidentfactors,calculated fromload entire system atthisservicelevel configurations areused toproject thelossesfor the Demand andenergylosses calculatedforeverycircuit using theloadfactor/loss factor method Energy loss(kWh)iscalculated foreveryconfiguration

Siemens condary LinesandService 112

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010      Siemens Power Transmission & Distribution, Inc., Power Technologies International Secondary ServiceDrops Overhead and underground Utility standard wiresizes Three wireortwo Secondary linestometer Residential 120/240v or threephase380v

Siemens 113

SiemensNeutral 220 V Meter 115

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010       Siemens Power Transmission & Distribution, Inc., Power Technologies International Secondary ServiceLines from same transformer Small industrial, commercial,and residentialaresupplied and singlephase laterals Three phase mostlyhaveradialsystems withtwophase Service dropsareattached May runinseveraldirections Have shortrunsfromtransformer 120/240 Volts

Siemens 116

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International Procedure Select representative sample Develop characteristic systems Determine powerfactor loads Obtain load researchinformation by customer classfor • •

Statistical sample,matchbudget Rural, city,urban

Siemens 117

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International Procedure (continued) energy) Allocate losses tothesubsystemtotal (demandand Use load/lossfactorfor energy Calculate demandlosses for secondaryservicelines Model withpowerflow orspreadsheet

Siemens 118

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010     Siemens Power Transmission & Distribution, Inc., Power Technologies International Meter Losses… meters cause the meter losses and excitation losses inthe mechanical andelectronic Friction lossesin therotating basis, butthese lossesaddupina largesystem Meter losses aresmallinmagnitude onanindividual point mechanical orelectronic meter atthecustomer’sdelivery Small amount Most meterlossesare no-load losses

Siemensenergy islostineachindividual

disk of mechanical meters 119

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010   Siemens Power Transmission & Distribution, Inc., Power Technologies International …Meter Losses meter losses total number ofmeterseachkind toobtainthetotal Meter lossesfor eachkind ofmeterare multipliedbythe be availablefrom manufacturers typical metersused.Otherwis Utilities usuallyhavedata regardingthelossesfor

Siemens e, thisinformationshould 120

Include substation andthecompanyuse meters Source isthe company recordsforinventory year (ornumber ofhoursthestudyperiod) Find thewatt lossforeachmeterandmultiply by8760hoursper

Siemens 121

Understanding System Losses

© 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010    Siemens Power Transmission & Distribution, Inc., Power Technologies International Procedure Energy= demand*8,760 hours Demand=number*1 watt (forexample) Determine meterinventory

Siemens 122

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010 Sum Three-Phase Electronic Three-Phase Mechanical Single-Phase Mechanical Siemens Power Transmission & Distribution, Inc., Power Technologies International Example ofCustomerMeter LossCalculation Meter Type Meter Quantity 488,597 Siemens530,202 27,390 14,215 Loss/Meter Watts 0.80 0.25 1.00 Demand Loss Loss Demand 390,878 411,940 14,215 6,848 Watts Energy LosskWh 3,433,469 3,618,482 124,865 60,148 123

Understanding System Losses © 2010 Siemens Energy, Inc., Power Technologies International (PTI) July 2010       Siemens Power Transmission & Distribution, Inc., Power Technologies International Unaccounted Losses Service withoutmeters (street lights&trafficsignals) Un-metered substationuse Un-metered companyuse Energy diversion (metertampering, meter bypass) Accounting practices Free service(charity, churches) •

Sometimes estimated (nometers)

Siemens 124

Siemens 125