Transformer On-Line Monitoring 2004 Sacramento... · Why On-Line Monitoring & Diagnostics? ......
Transcript of Transformer On-Line Monitoring 2004 Sacramento... · Why On-Line Monitoring & Diagnostics? ......
Transformer OnTransformer On--Line Line MonitoringMonitoring
Rowland JamesRowland James
EntergyEntergyNovember 8, 2004November 8, 2004
ProloguePrologue
Why OnWhy On--Line Monitoring & Diagnostics?Line Monitoring & Diagnostics?
Aging and Failure ModesAging and Failure Modes
Failure StatisticsFailure Statistics
Current Monitoring & Analysis MethodsCurrent Monitoring & Analysis Methods
Why OnWhy On--Line Monitoring & Diagnostics?Line Monitoring & Diagnostics?
Aging Fleet Aging Fleet Reducing Probability of Catastrophic FailureReducing Probability of Catastrophic Failure
Reducing NonReducing Non--Catastrophic Unscheduled OutagesCatastrophic Unscheduled Outages
Deferring Capital Costs of Upgrades/ReplacementsDeferring Capital Costs of Upgrades/ReplacementsExtending Overall Life of EquipmentExtending Overall Life of Equipment
Allowing ShortAllowing Short--Term OverloadingTerm Overloading
Reducing O&M CostsReducing O&M Costs
Insulating FluidInsulating Fluid2 Main Purposes:2 Main Purposes:
Dielectric InsulatorDielectric Insulator
Thermal TransferThermal Transfer
Additional Benefit:Additional Benefit:Transport Vehicle for Telltale Gases & Acoustical SignalsTransport Vehicle for Telltale Gases & Acoustical Signals
Combustible Gases are Released under Very Specific Combustible Gases are Released under Very Specific CircumstancesCircumstances
Transformer AgingTransformer Aging
Winding Insulation (i.e., Paper/Cellulose) Winding Insulation (i.e., Paper/Cellulose) The One Component with NonThe One Component with Non--Reversible Life Reversible Life Characteristic Characteristic –– It Will Age.It Will Age.
Factors Affecting Life of Cellulose:Factors Affecting Life of Cellulose:HeatHeat
Paper Moisture (Main Source of Degradation)Paper Moisture (Main Source of Degradation)
Oxygen Content of OilOxygen Content of Oil
Transformer Aging (contd.)Transformer Aging (contd.)
Failure StatisticsFailure StatisticsOutage Rates Generally RisingOutage Rates Generally Rising
Approximately 1.45% Prior to 1990Approximately 1.45% Prior to 1990
Approximately 5.5% After 1990Approximately 5.5% After 1990
Costs of Outages Due to RepairsCosts of Outages Due to RepairsMajor FailuresMajor Failures
$1.5 million After Event Vs. $200k+ via Early Detection$1.5 million After Event Vs. $200k+ via Early Detection
Catastrophic FailuresCatastrophic Failures$5+ million Post Event Vs. $200k+ via Early Detection$5+ million Post Event Vs. $200k+ via Early Detection
Current Monitoring Methods Current Monitoring Methods
ThermalThermal
Dissolved Gas Analysis (DGA)Dissolved Gas Analysis (DGA)ManualManual
OnOn--Line Line
Moisture DetectionMoisture Detection
Current Monitoring Methods ( contd.)Current Monitoring Methods ( contd.)
BushingsBushings
LTC Oil Dielectric StrengthLTC Oil Dielectric Strength
Acoustical AnalysisAcoustical Analysis
Other Traditional MethodsOther Traditional Methods
ThermalThermal
Top & Bottom OilTop & Bottom Oil
Winding Temperature (Direct, Calculated or Winding Temperature (Direct, Calculated or Simulated)Simulated)
Ambient Temperature (remote from any heat Ambient Temperature (remote from any heat source in the substation)source in the substation)
Control Cabinet TemperatureControl Cabinet Temperature
Tank Temperature (surface mount)Tank Temperature (surface mount)
Dissolved Gas AnalysisDissolved Gas AnalysisDGA DGA –– Biggest Bang for the Buck!Biggest Bang for the Buck!
InexpensiveInexpensive
Very Sensitive to Changes in Main TankVery Sensitive to Changes in Main Tank
Can be applied to LTC’s and OCB’sCan be applied to LTC’s and OCB’s
Extremely ReliableExtremely Reliable
Trendable Trendable
Dissolved Gas Analysis (contd.)Dissolved Gas Analysis (contd.)
New TechnologiesNew TechnologiesOn Line DGA/Fault Gas On Line DGA/Fault Gas
On Line Hydrogen & Moisture On Line Hydrogen & Moisture
Some Suppliers GESome Suppliers GE--Hydran, Morgan & Hydran, Morgan & SchaeferSchaefer
BushingsBushings
Manual Power Factor measurements (Doble, Manual Power Factor measurements (Doble, Vanguard, Omicron, Biddle, etc.)Vanguard, Omicron, Biddle, etc.)
Capacitance tap bushing monitor. (Doble Capacitance tap bushing monitor. (Doble continuous measurement, others may require continuous measurement, others may require site visits in order to download data. (Cutler site visits in order to download data. (Cutler Hammer, ZTZ)Hammer, ZTZ)
LTC/TCULLTC/TCUL
Dielectric Strength Tester (onDielectric Strength Tester (on--line Developed line Developed by MIT & Entergy)by MIT & Entergy)
Contact Wear Indicator (EPRI R&D project)Contact Wear Indicator (EPRI R&D project)
DGA for LTCDGA for LTC
Infrared MonitoringInfrared Monitoring
Differential Temperature MonitoringDifferential Temperature Monitoring
Fans & PumpsFans & Pumps
Pumps Pumps –– apply bearing wear indicators to apply bearing wear indicators to pump. Monitor voltage, current & flow.pump. Monitor voltage, current & flow.
Fans Fans -- Monitor voltage, current and/or Monitor voltage, current and/or employ air flow indicator.employ air flow indicator.
Cycle lead and lag for fans (back up with Cycle lead and lag for fans (back up with mechanical control)mechanical control)
NonNon--monitoring issue but important for fans monitoring issue but important for fans –– totally enclose fan cages to prevent bird totally enclose fan cages to prevent bird cages.cages.
Voltage & CurrentVoltage & Current
Use for Dynamic loading and Loss of life Use for Dynamic loading and Loss of life calculationscalculations
Current Current –– Clip on CT’s (1:1) but hard wired Clip on CT’s (1:1) but hard wired CT’s more reliable (if transient measurements CT’s more reliable (if transient measurements desired)desired)
Voltage Voltage –– use existing PT’s, BPT’s or CCVT’suse existing PT’s, BPT’s or CCVT’s
Partial Discharge DetectionPartial Discharge Detection
Acoustic Acoustic –– short term testing (portable short term testing (portable ––magnetic accelerometers). Use for magnetic accelerometers). Use for benchmarking and trouble investigations benchmarking and trouble investigations (gassing also detectable)(gassing also detectable)
Permanent installations for desired Permanent installations for desired continuous monitoring (bushing mounted)continuous monitoring (bushing mounted)
Monitoring LevelsMonitoring Levels
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Generator Step Up’s (base load) & Generator Step Up’s (base load) & Transmission Autotransformers, Transmission Autotransformers,
Criticality Criticality -- HighHigh
Maximum Maximum MonitoringMonitoring
Monitoring Levels (contd.)Monitoring Levels (contd.)
2 2
High MVA, Peaking GSU’sHigh MVA, Peaking GSU’s
Criticality Criticality –– ModerateModerate
Medium MonitoringMedium Monitoring
Monitoring Levels (contd.)Monitoring Levels (contd.)
3 3
Specific casesSpecific cases
Critical loads & Processes such as Critical loads & Processes such as
Oil Refineries, Chemical Plants,Oil Refineries, Chemical Plants,
Medical Facilities, Military InstallationsMedical Facilities, Military Installations
Maximum to Medium MonitoringMaximum to Medium Monitoring
Monitoring Levels (contd.)Monitoring Levels (contd.)
4 4
Normal use age Normal use age
Conventional MonitoringConventional Monitoring
New vs. RetrofitNew vs. Retrofit
New New –– Factory installed ( should be covered Factory installed ( should be covered in purchase specification). Additional thermal in purchase specification). Additional thermal wells, etc.wells, etc.
Retrofit Retrofit –– Additional thermal wells (add to Additional thermal wells (add to radiators?); magnetic RTD’sradiators?); magnetic RTD’s
Pumps Pumps –– Replace GER/Harley/Cardinal Replace GER/Harley/Cardinal
Data Handling & StorageData Handling & Storage
Information vs. dataInformation vs. dataExpert System Expert System –– Local and RemoteLocal and Remote
CommunicationsCommunicationsLocal Local --LAN, Fiber Optics, Twisted PairLAN, Fiber Optics, Twisted Pair
Remote Remote –– WAN, Fiber Optics, Twisted Pair, WAN, Fiber Optics, Twisted Pair, Satellite Satellite
HMI local and/or RemoteHMI local and/or Remote
ConclusionConclusionWhy Transformer Why Transformer
OnOn--Line Monitoring?Line Monitoring?