Overview of the Cable Diagnostic Focused Initiative Project

1 3/29/201212012 International Conference of Doble Clients , March 25 - March 30, 2012 Overview of theOverview of theCCable able DDiagnostic iagnostic FFocused ocused IInitiativenitiativeProjectProjectNEETRA CNEETRACN ational Electric Energy Testing Research and Applications CenterNational Electric Energy Testing Research and Applications CenterJean Carlos Hern ndez Mej a2012 International Conference of Doble Clients Boston, MA, USAM arch 25 - March 30, 201212012 International Conference of Doble Clients , March 25 - March 30, 20122 GTRI/DoE Disclaimer The information contained herein is to our knowledge accurate and reliable at the date of publication. Neither GTRC nor The Georgia Institute of Technology nor NEETRAC will be responsible for any injury to or death of persons or damage to or destruction of property or for any other loss, damage or injury of any kind whatsoever resulting from the use of the Project results and/or data.

2 GTRC, GIT and NEETRAC disclaim any and all warranties both express and implied with respect to analysis or research or results contained in this report. It is the user's responsibility to conduct the necessary assessments in order to satisfy themselves as to the suitability of the products or recommendations for the user's particular purpose. No statement herein shall be construed as an endorsement of any product or process or provider Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Department of Energy This material is based upon work supported by the Department of Energy under Award No DE-0E00001883/29/201222012 International Conference of Doble Clients , March 25 - March 30, 20123 Outline NEETRAC Overview . Why do we need diagnostics ? Basics of Power Cable Systems. Basics of Power Cable diagnostics .

3 Cable Diagnostic Focused Initiative (CDFI) Project . Evolution of VLF-Tan criteria (PE Based). Dissemination. Reflections. Q& International Conference of Doble Clients , March 25 - March 30, 20124 NEETRAC Overview 15 years ago NEETRAC was set up as a self supporting centerwithin the School of Electrical and Computer Engineering of the Georgia Tech. NEETRAC is a membership based center, conducting research programs for the Electric Energy Transmission and Distribution Industry. Utility Members: Serve over 70,000,000 customers. Manufacturing Members: Primary suppliers of T&D equipment to electric utilities in the Canada, Mexico & United International Conference of Doble Clients , March 25 - March 30, 20125 Members Electric Compounds Edison Co. of New Power Virginia Power10. Dow Chemical Company11. Duke Energy Company12. Entergy13. Exelon / Commonwealth Edison & PECO14.

4 First Energy15. Florida Power & Light16. GRESCO17. Hubbell Power Systems18. Landis + Gyr19. MacLean Power Systems20. NRECA21. NSTAR22. PPL Electric Utilities23. Pacific Gas & Electric24. Pacificorp25. Progress Energy26. Prysmian27. Public Service Electric & Gas28. S&C Electric29. Smart Wire Grid30. South Carolina Electric and Gas31. Southern California Edison32. Southern Company33. Southern States34. Southwire35. Thomas & Betts36. TVA37. TE Connectivity38. Varentec39. Viakable40. Zenergy2012 International Conference of Doble Clients , March 25 - March 30, 201263/29/201242012 International Conference of Doble Clients , March 25 - March 30, 2012735302520151051200150100500 YearFailures [#/Year]O bserv ed F ailuresFailure EstimatePredictionHistorical2012 International Conference of Doble Clients , March 25 - March 30, 2012 Cable Failures per Year200520001995199019851980197519701000 80060040020008 Underground Cable system infrastructure is complex and aging.

5 Failures are increasing. If not addressed then old infrastructure will not support future operation of the grid. Not enough money / manufacturing capacity to simply replace because they are old. Need Diagnostic tools to prioritize Active Asset Management. Always remember we talk about the Cable SYSTEM, not just Cable . Why do we need diagnostics ? times3/29/201252012 International Conference of Doble Clients , March 25 - March 30, 2012 Power Cable Systems92012 International Conference of Doble Clients , March 25 - March 30, 201210 The Power Cable SystemTerminationsSplicesDirect buried conduitDirect buriedInstallation MethodsVoltage classification:LV < 6 kVMV 6 - 36 kVHV 36 - 161 kVEHV > 161 kVInsulation MVLaminatedExtrudedPILC ThermoplasticThermosetHMWPEXLPETRXLPEEPR P rior TechnologiesToday s TechnologiesCourtesy of NEETRAC3/29/201262012 International Conference of Doble Clients , March 25 - March 30, 2012 Basics Power Cable Diagnostics112012 International Conference of Doble Clients , March 25 - March 30, 2012In the ideal case, power Cable Diagnostic techniques must be123/29/201272012 International Conference of Doble Clients , March 25 - March 30, 201213 Safe2012 International Conference of Doble Clients , March 25 - March 30, 201214 Effective3/29/201282012 International Conference of Doble Clients , March 25 - March 30, 201215 Useful2012 International Conference of Doble Clients , March 25 - March 30, 201216 Valuable3/29/201292012 International Conference of Doble Clients , March 25 - March 30.

6 201217 Diagnostic Testing of Cable Systems A field test made during the operating life of a Cable system that is intended to determine and locate aging or degradation that may cause Cable and accessory failure . Tests may be: On-line or off-line. Bulk property or a localized. Low or medium probability of failure in test. Periodic testing to develop trends probably gives better assessment than a one-time International Conference of Doble Clients , March 25 - March 30, 201218 For Effective Diagnostic Testing: Need to knowaging/degradation and failure mechanisms, and rate of aging of different Cable systems. Need to measureproperties or characteristics of Cable systems, bulk and local, that give an indication of how much aging has occurred. Need to interpretdata to estimate remaining more details that are available, the more accurate the interpretation3/29/2012102012 International Conference of Doble Clients , March 25 - March 30, 201219 CCable able DDiagnostic iagnostic FFocused ocused IInitiativenitiativeProjectProject2012 International Conference of Doble Clients , March 25 - March 30, 201220At the Start (< 2005) For many utilities, the usefulness of Diagnostic testing was unclear.

7 The focus was on the technique, not the approach. The overall benefits were not well defined. There was almost no independently collated and analyzed data. There were no independent tools for evaluating Diagnostic effectiveness. 3/29/2012112012 International Conference of Doble Clients , March 25 - March 30, 201221 Diagnostic Tests AvailableBulk Property Measurements: Tan at single frequency ( , 60 Hz, 0,1 Hz, etc). Tan over frequency range (dielectric spectroscopy). Recovery voltage. Polarization/depolarization currents. Neutral Property Measurements: Visual inspection. Withstand. Partial discharge. Time domain reflectometry. 2012 International Conference of Doble Clients , March 25 - March 30, 2012 ElementCDFI Focus, Phase ICDFI Focus, Phase IIVoltage LevelMVMV & some HVTest TypeCondition AssessmentCondition Assessment & Commissioning / RecommissioningCableService AgedService Aged & Laboratory Aging of Service AgedDiagnosticsCurrently in use in USCurrently in use in US & those that might reasonably be usedDataUtility Distribution SystemDistribution, Industrial & TransmissionLab StudiesField Aged CableCable & Accessories22 CDFI Phase I vs.

8 CDFI Phase II3/29/2012122012 International Conference of Doble Clients , March 25 - March 30, 2012 Phase II ParticipantsCDFID iagnostic ProvidersDept of EnergySupportersNon NEETRACM embersNEETRAC Members232012 International Conference of Doble Clients , March 25 - March 30, 2012 ParticipantsUtilitiesManufacturersDiagno stic ProvidersAmerican Electric PowerFirstEnergyBorealisCablewise/UtilxA merenFPLC ooper Power SystemsHDW ElectronicsBC HydroHydro QuebecDowHigh Voltage, IncCenterPoint EnergyNRECAP rysmianHipotronicsConsolidated EdisonPacific Gas & Electric SouthwireHV DiagnosticsDominionPacifiCorpTE ConnectivityHV TechnologiesDuke EnergySCE&GKinectricsEPRIS outhern California TechImp SPAE xelonSouthern Company243/29/2012132012 International Conference of Doble Clients , March 25 - March 30, 2012 Withstand Tests. AC Commissioning Tests. PD Tests (Online & Offline). Very Low Frequency (VLF). Damped AC.

9 Time Domain Spectroscopy. Artificial than describe ALL THE WORK we have chosen to follow the evolution of VLF Tan tests as this provides a good Roadmap for the workWorking in the following areas252012 International Conference of Doble Clients , March 25 - March 30, 2012 Evolution of VLF-Tan Criteria(PE-Based)263/29/2012142012 International Conference of Doble Clients , March 25 - March 30, 2012 TCSCTTan Cable insulation is represented by an equivalent circuit. Circuit consists of a resistor and a Hz or 60 HzRCVIRICI1'RCITanDFIRC ==== Cable system ( Cable , splices, and terminations) is reduced to simple International Conference of Doble Clients , March 25 - March 30, 2012 VLF Tan Diagnostic Features Time [min]Tan-delta [1e-3] [Uo]VoltageMeancould be used)Standard Deviation - IQRS catter (represented byTip UpFeature :Tan LevelFeature :Voltage DependenceFeature :Time Dependence3/29/2012152012 International Conference of Doble Clients , March 25 - March 30, 201229 Feature : Tan LevelFeature :Voltage DependenceFeature :Time DependenceCondition AssessmentVLF Tan Diagnostic Features (2) 2012 International Conference of Doble Clients , March 25 - March 30, 201230 VLF Tan Diagnostic Features (3) How to use the features?

10 Have all the features the same relevance? How to handle different insulation types? How to establish criteria?3/29/2012162012 International Conference of Doble Clients , March 25 - March 30, 201231 Tan Equipment2012 International Conference of Doble Clients , March 25 - March 30, 201232 Diagnostic Spectrum Extreme conditions are easy to decide what to do about. What to do about the ones in the middle? How to define the boundaries?NNOOAACTIONCTIONRREQUIREDEQUI REDFFURTHERURTHERSSTUDYTUDYAACTIONCTIONR REQUIREDEQUIREDI ncreasing Tan Diagnostic Feature3/29/2012172012 International Conference of Doble Clients , March 25 - March 30, 2012 Evolution of VLF-Tan Criteria(PE-Based)332012 International Conference of Doble Clients , March 25 - March 30, IDTD [E-3] @ UoPE BasedTan and the IEEE Std. 400 (2) IDTD [E-3] @ BasedApproximately50 %of alltested Cable segments haveto be replaced3/29/2012182012 International Conference of Doble Clients , March 25 - March 30, 2012 Evolution of VLF-Tan Criteria(PE-Based)352012 International Conference of Doble Clients , March 25 - March 30, 201236 Feature : Tan LevelFeature :Voltage DependenceFeature :Time DependenceCondition AssessmentVLF Tan Diagnostic Features 3/29/2012192012 International Conference of Doble Clients , March 25 - March 30, 2012 Mean Tan Distributions by of Tan Delta @ Uo (E-3)Percent9580 FilledPaperPEIns Class2012 International Conference of Doble Clients , March 25 - March 30, 2012 Service Failures After Time Feb.