Name Of Presentation: Three phase induction motor

1. NAME OF PRESENTATION: THREE
PHASE INDUCTION MOTOR
Prepared by
Name : Md Ashraful Islam
ID. 1401EEE50015
Name of subject: Electrical machines 2
Name of Teacher : MR. TANVIR HOSSAIN
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2. Course outline:
1.Introduction
2.Type ofelectricalmachine
3. Typeof 3-pninductionmotor
4.BasicPrinciple
5.WorkingPrinciple
6.Component'sofinductionmotor
7.Application
8.Comparisonbetween1-phI.M.&3-phI.M.
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3. Introduction
» ElectricalMachinesareElectromechanicalenergy
conversiondevices.
» Electricalmotorcovertselectricalenergyinto
mechanicalenergyandelectricalgeneratorsarevice
versa.
» MostoftheIndustrialloadareinductive,especially
3-phinductionmotorsarewidelyusedinindustrial
applicationsfor continuousoperation.
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4. Types of electrical machines
» DCMachines:-
⧖DCMotor
⧖DCGenerator
» DCMotor:
⧖DCShuntMotor
⧖DCSeriesMotor
⧖DCCompoundWoundMotor
» DCGenerator
⧖DCShuntGenerator
⧖DCSeriesGenerator
⧖DCCompoundWoundGenerator
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5. Principle of operation
» ARotating Magneticfield(RMF)issetup inthe
stator whena3-Phasesupply isgiven.
» Thestationary rotor cuttherevolving fieldand
duetoelectromagnetic inductionane.m.f.isinduced
intherotorconductor.
» Astherotorconductorisshortcircuitedcurrent
flowsthroughthem.
» It becomesacurrentcarrying conductorin
magnetic fieldandstart rotating. 5

6. Slip of induction motor
»Inductionmotorrotoralwaysrotateat aspeedless
thansynchronousspeed.
» Thedifferencebetweentheflux (Ns) andthe
rotorspeed(N)iscalledslip.
» %Slip(s) =
Ns–N
Ns
*100
Where,Ns=SynchronousSpeed
N=ActualSpeedofrotor
» Slipspeed=Ns–N
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7. Image of 3-pn induction motor
3-pn induction motor
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8. Terminals of 3-pn induction motor
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9. Cut view of 3-pn induction
motor
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10. Component of 3-ph induction motor
» Frame
» Stator
» StatorWinding
» Rotor
» RotorWinding
» CoolingFan
» Bearings
Frame:Frameprovidesmechanicalsupporttothe
statorandrotor.Itismadefromcastingmaterials.
Stator:Itisstationarypartofinductionmotor.It
consistsstatorwindingIt ishousedonthemotor
frame.
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11. Windings
» StatorWindings:
⧖Starconnected
⧖Deltaconnected
» RotorWindings:
⧖Itiswoundasrotorbarsandshort circuitedat
boththeendsthroughendrings.
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12. Crosse section of stator & rotor
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13. Type of 3-ph induction motor
AccordingtorotorconstructionitcanbeClassifiedin
twocategory accordingtorotorConstruction:-
Squirrel cage induction motor
•
Slip ring induction motor
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14. Comparison of Squirrel cage Induction
Motor & Slip ring Induction Motor
SlipringInductionMotor:-
» Ithashigh startingtorquecomparetosquirrelcage
IM
» Constructioniscomplicated
Maintenancecostishighcomparetosquirrelcage
IM
» Starterrequirescompulsory
»Cannotuseatexplosivearea
*Application:-
» Crane,hoist,liftandwherehigh startingtorqueis
required
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15. Comparisonof SquirrelcageInductionMotor&Slip
ringInductionMotor
SquirrelcageInductionMotor:-
»Mostoftheapplicationofindustrialaswellasdomesticare
thistypeofinductionmotor.
»Itsconstructionissimpleandrugged.
»CheapcoparetoslipringIM
»Maintainanceiseasy
» CostislesscomparetoslipringIM
» Canuseatexplosivearea
» StartingtorqueislowcomparetoslipringIM
Application:-
» Loathmachine,Compressors,centrifugalpump,in
agricultureetc.wherecostismostimportantfactor
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