Motor Power Point

7/28/2019 Motor Power Point

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Test Details1. Electrical Signature Analysis.2. Online Partial Discharge (By Acoustic Emission)

3. Harmonic Analysis. (Up to 50th

Harmonic)4. Thermography (Maximum 25 Images)5. Vibration Analysis. (FFT analysis)


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Electrical Signature Analysis. What is Electrical Signature Analysis?

Electrical Signature Analysis is the procedure of capturing a Motors current & voltage signals andanalyzing them to detect various faults.


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What are the faults can Electrical Signature

Analysis detect?1. Rotor Bar Damage2. Misalignment / Unbalance

3. Foundation Looseness4. Static eccentricity 5. Dynamic eccentricity 6. Stator Mechanical faults7. Stator electrical Faults8. Defective bearings.


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Advantages of Electrical Signature

Analysis 1. On-line, no stoppage required.

2. Remote monitoring, no need to approach the motor.

3. Accurate detection of electrical & mechanical problems.

4. Works with Induction, Synchronous & DC motors &generators as well as VFDs.


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How does signature analysis work?The frequency spectrum enables us to see all theharmonic components of V & I. All electrical & Mechanical faults change the fluxdistribution inside motor hence generate harmonics in

the current.Superimposing the current & voltage spectra enablesus to distinguish between the supply harmonics & thefault harmonics.

The Harmonics generated by each fault will bedifferent.Studying the distribution of these fault harmonicsenables identification of the fault.


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How are the Current & Voltage signalscaptured?

Clamp on probes are placed around the supply cablefor LT motors and around the measuring or protectionCT secondary for HT motors. Voltage leads are attached to the supply terminals forLT motors & at the bus PT secondary for HT motors. All testing is done at the MCC or the Motor Control

Panel No need to approach the Motor.


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Instrument to be usedMake: EMPATH

(Electric Motor Performance Analyzing & Trending

Hardware)


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Online Partial Discharge (By Acoustic

Emission)DefiniationLOW FREQUENCY SOUND WAVES RANGE IN SIZE FROM 3/4(1.88 CM) TO 56 (16.9 M) (assuming the average hearing is 16.5

kHz)

HIGH FREQUENCY (ULTRASOUND) SOUND WAVES RANGE INSIZE FROM 1/8 (0.34 CM) TO 5/8 (1.7 CM) (assumingultrasound range from 20 kHz-100kHz )


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Advantages of UltrasoundUltrasound Condition Monitoring improves assetavailability, increases production efficiencies andoutput and reduces energy loss leading toincreased uptime and company profitability.

Ultrasound Condition Monitoring accurately andeasily inspects potential problems, ensuring safeand secure plant operations positively impacting

your bottom line.


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Applications

All Switch yard equipments

Turbine, Furnace,Pressure vacuum

Leaks, Condenser TubeLeakage, Heat

exchangers

All Rotating Equipments


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Instrument to be used Make Ultra

probe


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Harmonic Analysis. (Up to 50 th Harmonic)

DefinitionHarmonics are integral multiples of some fundamental frequency that , when added together , result in adistorted wave form.

In a power system the fundamental frequency is50Hz ,this is also called

1 st harmonic i.e. 1X 50 Hz=50 Hz &2 nd harmonic is 2X50 Hz=100Hz,3 rd harmonic is 3x50Hz=150 Hz , etc.

The semiconductor devices that alters the 50Hz sinewave, distorts both the current and voltage waveforms.

The distorted wave form frequency will be higher thanthe fundamental frequency and is integer multipliable .


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DECOMPOSITION OF A DISTORTEDWAVE FORM

Distorted waveFundamental wave

50Hz

5 th Harmonic wave5X50=250Hz 7

thHarmonic wave7X50=350Hz


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SOURCES OF HARMONICS VFD (Variable Frequency Drivers). Transformer under no loads & light loads.Saturated reactors.

Thyristor controlled motor drives .Arc furnishesArc weldersInduction furnacesGas discharge light & CFL.Rectifiers.Electrolysis plants .Energy conservation devices.Ex: soft starters, electronic ballasts & fan regulators.

Equipments with SMPS(switch mode power supply),

EX: TV receivers ,PCs & Office Machines (UPS, Fax m/c,Printer, Scanners, etc).CVTs. AC/DC, AC/AC,DC/AC Converters.AC/DC Battery Chargers.


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Effects of HarmonicsSl. No Equipment Effects of Harmonics

1 Circuit breakers False tripping2 P.F Corr. capacitors Blowing of fuses, overheating

BurstingSeries/parallel resonanceOver voltagesHigh circulating current

3 Telecommunication lines Interferences

4 Induction-type meters Read high

5 Average reading meters Read low

6 Fluorescent lamps High peak value due toHarmonics reduces life

7 Protective relays Unpredictable behavior

8 Fan Motors Electronic regulators Produce a humming sound.

9 Neutral of 3-phase Zero-seq. current add

10 4-wire system Size to be increased Neutral displacement


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Effects of HarmonicsSl. No Equipment Effects of Harmonics

1 Machines Increased lossesLower efficiency Counter-rotating mmf

2 Resistive parts Added loss

3 Magnetic circuits Added loss

4Computers Interference

5 Auto-voltage regulator Malfunctioning

6 Audio PA system Interference

7 ZnO arrensters Increased loss

8 Conductor Cable heating Tripping of protection

9 Transformers Overheating of the windings Thermal insulation loss due to heatingCopper and Metal loss (Hysteris and Foucault)Reduction in performanceExtra-large transformer

Transformer saturation (creates greater distortion)

10 Neutral Conductor Overcurrent flowing in neutralHeating on neutral


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Filters Definition

Harmonic Filters isolate harmonics current to protectelectrical equipment from damage due to harmonic voltage

distortion. Harmonic filters mitigate the detrimental effects of detrimental harmonic distortion.

Types of Harmonic filters .Active filters.

Passive filters.


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Benefits of Harmonic Filters.

Reduced Electrical Power Bills because of reduced consumption.

Reduced Electrical Power Bills by Limiting distortion.

Improved Productivity through decreased troubleshooting &

maintenance.

Improve power factor ratings through harmonic recombination.

Isolated harmonic currents.

Minimize equipment problems through THD cancellation

Reduce wasted energy

Minimize current carried in plant cables.


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Thermography Testing Advantages

It shows a visual picture so that can help comparetemperatures over a large areaIt is capable of catching vision of moving targets inreal time Able to find deteriorating components prior to failure

Measurement in areas inaccessible or hazardous forother methodsIt is a non-destructive test method


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HOT SPOTS Monitoring

1. IR losses occur & results in heat generation.2. Increased IR loses at a particular point can be

attributed to increase contact resistance.3. It may be because of

* loosening due to contraction & expansion ,* erosion of surface or displacement of contactarea due to vibrations etc


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Examples


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Examples


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Vibration Analysis (FFT Analysis)Using vibration analysis on rotating machinery, enablesthe early detection of faults before breakdown. This willreduce economical losses to production and equipment,saving industry millions of dollars in machine downtime.

The evaluation of the changes in vibration response,critical speeds and stability of a machine, has becomean important part of most maintenance programs. Theaim therefore, is to evaluate machine condition forweaknesses. This will enable the diagnosis of faults,therefore repairs can be planned and performedeconomically.


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Instrument to be used
http://c/Documents%20and%20Settings/admin/Desktop/YouTube%20-%20Vibration%20Analysis%20with%20VibXpert.htm


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Advantages of Vibration Analysis1. Focus maintenance and operations by predicting functional failures,

forecastingfailure mode and estimating time until failure; conveniently schedule targeted

proactive failure interventions and prevent loss of productionavailability/productioncapacity/product quality.

2. Improve reliability (mean time to repair, mean time between failure, plantavailability and utilization.

3. Decrease maintenance cost and optimize returns, reduce labour and materialcost

Needed for preventive maintenance routines, minimize energy consumption,increase

product quality, increase production capacity, reduce spare parts inventory,provide

consistent equipment performance, provide reliable production, increaseequipment

availability, reduce downtime, extend asset life, reduce overhauls, preventmaintenance overkill and maintenance collateral damage, improve staff timeallocation, improve repair scheduling, save overtime cost.

4. Define details of failures and repair requirements.

5. Optimize preventive maintenance routines.

6. Avoid health and safety and environmental risks.


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THANK YOU

Motor Power Point

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