PowerPoint Presentation

Infrared thermography on electrical system

ByName: Venkanagouda P.CUSN:Under the Guidance of Prof.Praveen .H

A seminar on

Department of Electrical and Electronics EngineeringK. L. E. Institute Of Technology, Hubli.

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ContentsIntroduction What is thermographyTest instrumentInspection of components and faultsCondition monitoring Electrical applications Benefits of infrared thermography Advantages and limitationsCase studiesConclusionReferences

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IntroductionIn 1800, astronomer Sir William Herschel discovered infrared It is simply a picture of heatOn-line condition monitoringfast, reliable and accurate temperature profile of any material surface.New level of diagnostic aid and problem solving Rapid growth in electric utilities and industrial sectors are embracing the technology.3

Infrared thermography_What it is?An Infrared Camera Senses Infrared Radiation It is objective image-giving measuring method Enabling Us To Visualize The Thermal World surface temperature can be determined contactless. A Processor In The Camera Assigns Color To The Infrared Radiation- Different Color Equals Different Temperature

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In an electromagnetic spectrum the IR region appears between 0.8 micron to 1000 micron wavelength . This wavelength of IR spectrum is more than that of a visible spectrum5

Test Equipment Hand held portable cameraBattery PoweredRange..-20c to +1500cSensitivity..0.1c at 30cReal time display Image Recording capability

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The infrared camera evaluates and converts heat energy into meaningful temperatures. Components in various states of failure will emit more heat as a direct result of more energy dissipated into the component.

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Objectives of TestTo detect hot or cold areasTo determine absolute temperatureTo view Thermal profilesTo detect temperature lossfirst determine a baselinebaseline is established when the system is operating under normal load and operating conditions the baseline images and data will be stored and compared to new data collected from each inspection interval

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Electrical Inspection Items

. TransformerPad MountDry OverheadDistribution PanelsRectifiersControl PanelsDrivesCapacitor BanksAny Electrical ConnectionMain SwitchgearMotor Control Centers

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Typical Faults in a electrical networkElectrical Distribution Equipment

Transformers

Motors Loose connections or poor contacts, unbalanced loads, overloading, overheating

Loose connections, overheated bushings, poor contacts, overloading, blocked /restricted cooling passages

Overheated bearings, unbalanced loads, overheating /overloading, blocked cooling passages

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Electrical Applications Power generation: hydro, thermal, and nuclearPower distribution: transmission, switchyards, substations, and distributionIndustrial users: all process and manufacturing industriesCommercial users: warehouses, office buildings, banks, schools, virtually all buildings

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Condition monitoring

No electrical system is 100% efficientTemperature is an excellent indicator to the operating condition It is well understood that the life of electrical components and materials is drastically reduced as temperatures are increased. IEEE, ANSI, IEC and manufacturers all publish standards and temperature ratings for electrical componentsthe job of the thermographer to identify record, analyze and diagnose indications of abnormal heat transfer in the electrical equipment or components12

Exception Repair Priority CriteriaPriority 0 Temperature Difference 10F or Less No Corrective Measures Required At This Time. Priority 4 Temperature Difference Over 100F Corrective Measures Required ImmediatelyPriority 3 Temperature Difference 30F to 100F Corrective Measures Required As Soon As PossiblePriority 2 Temperature Difference 20F to 30F Corrective Measures Required As Scheduling Permits Priority 1 Temperature Difference 10F to 20F Corrective Measures Required At Next Maintenance Period13

Exception Example Breaker LoadHot Spot Temperature.71FReference Temperature55FTemperature Difference..16FRepair Priority 0No Corrective Measures Required At This Time

Breaker Load A-105 amps B-150 amps C-167 amps14

Exception Example Main Switchboard Fused SwitchHot Spot Temperature...311FReference Temperature..151FTemperature Difference...160F

Repair Priority 4Corrective Measures Required Immediately

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Application in distribution systemIsolators, circuit breakers, Current Transformers, Potential Transformers, Distribution Transformers, bus bars etc. Most faults are encountered in the form of hot-spots at contact terminals which may be due to lose contact, corrosive nuts & bolts, broken conductor strands etc

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Applications Power Circuit of Electrical Drives

loose contacts at Motor Control Centre'ssevere voltage unbalance is at the motor terminal end lead to single-phasing This results in malfunctioning of the motor415 volt 75 KW induction motor (101 0C) at MCC breaker terminal with ambient about 30 0C in R-phase resulting in a voltage unbalance of about 4.7% at motor terminal

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Benefits of Periodic Electrical Infrared Inspections Predictive Maintenance...Allows Scheduling Of Repairs, Forward Buying. The reduction in disassembling, rebuilding or repairing components

Reduces Downtime Find It, Repair It, Before It Blows Up and Stops Production

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SafetyGreater system security Improved and less expensive maintenance More efficient inspections Reduced outage and operational costs

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Advantages and LimitationsAdvantagesLimitationsIt is a non-contact type technique.Fast, reliable & accurate output.A large surface area can be scanned in no time.Presented in visual & digital form.Software back-up for image processing and analysis.Requires very little skill for monitoring.Can work at a distancePortableConvincing ResultsCost of instrument is relatively high.Unable to detect the inside temperature if the medium is separated byglass/ polythene material etc.Operator experience is essentialFilters may be needed for certain applicationsSensitivity and Resolution reduce with distance and angle of view

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Case study 1

Consequence of Application of Thermography in a switchyard of a Captive Power Plant21

Case study 2TransformerExcessive transformer loading.Excess current in the neutral of the transformer.Problems in the cooling system.High harmonic content in the power supply.Sustained overvoltage which exists for a long period of time.47.2C

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Case study 3Transmission lines23

A high-temperature spot is found at the connector of phase-T conductor at the jumper of the riser pole. it shows bad electrical connection

ConclusionsProtect catastrophic equipment failures and unscheduled plant shutdowns a fast, reliable and accurate maintenance priorities, enhance operational safety and contribute to a stronger bottom line.Enhancing and preserving system reliability and reducing maintenance costs

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=$1.00$4.00

REFERENCES

FLIR Infrared Cameras Help Detect the Spreading of Swine Flu and Other Viral Diseases Applegate.co.uk (2009-04-29). Retrieved on 2013-06-18.Poryev V.A., Poryev G.V. "Experimental determination of the temperature range of a television pyrometer" in Journal of Optical Technology, Volume 71, Issue 1, pp. 7071 (2004)Maldague X. P. V., Jones T. S., Kaplan H., Marinetti S. and Prystay M. "Chapter 2: Fundamentals of Infrared and Thermal Testing: Part 1. Principles of Infrared and Thermal Testing," in Nondestructive Handbook, Infrared and Thermal Testing, Volume 3, X. Maldague technical ed., P. O. Moore ed., 3rd edition,Columbus, Ohio, ASNT Press, 2001, 718 p..Infrared Temperature Theory and Application. Omega.com. Retrieved on 2013-06-18..Snell, J.; Renowden, J. (2000). "Improving results of thermographic inspections of electrical transmission and distribution lines".2000 IEEE ESMO 2000 IEEE. ESMO 2000 Proceedings. Global ESMO 2000. The Power is in Your Hands (Cat. No.00CH37183). p.135.doi:10.1109/TDCLLM.2000.882811.ISBN0-7803-6625-5.http://halut.tripod.com/infrared.htm

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26Thank you