怎么洗保暖内衣

1TrainingSessiononEnergyEquipmentElectricMotorsPresentationfromthe“EnergyEfficiencyGuideforIndustryinAsia”www.energyefficiencyasia.org©UNEP2006©UNEP2006TrainingAgenda:ElectricMotorsIntroductionTypesofelectricmotorsAssessmentofelectricmotorsEnergyefficiencyopportunities3©UNEP2006Introduction•Electromechanicaldevicethatconvertselectricalenergytomechanicalenergy•Mechanicalenergyusedtoe.g.•Rotatepumpimpeller,fan,blower•Drivecompressors•Liftmaterials•Motorsinindustry:70%ofelectricalloadWhatisanElectricMotor?4©UNEP2006IntroductionHowDoesanElectricMotorWork?(Nave,2005)12345©UNEP2006IntroductionThreetypesofMotorLoadMotorloadsDescriptionExamplesConstanttorqueloadsOutputpowervariesbuttorqueisconstantConveyors,rotarykilns,constant-displacementpumpsVariabletorqueloadsTorquevarieswithsquareofoperationspeedCentrifugalpumps,fansConstantpowerloadsTorquechangesinverselywithspeedMachinetools6©UNEP2006TrainingAgenda:ElectricMotorsIntroductionTypesofelectricmotorsAssessmentofelectricmotorsEnergyefficiencyopportunities7©UNEP2006TypeofElectricMotors•Motorsarecategorizedonthebasisofinputsupply,constructionandoperationprincipoles•TEXTClassificationofMotorsElectricMotorsAlternatingCurrent(AC)MotorsDirectCurrent(DC)MotorsSynchronousInductionThree-PhaseSingle-PhaseSelfExcitedSeparatelyExcitedSeriesShuntCompound8©UNEP2006TypeofElectricMotors•Fieldpole•Northpoleandsouthpole•Receiveelectricitytoformmagneticfield•Armature•Cylinderbetweenthepoles•Electromagnetwhencurrentgoesthrough•Linkedtodriveshafttodrivetheload•Commutator•OverturnscurrentdirectioninarmatureDCMotors–Components(DirectIndustry,1995)9©UNEP2006TypeofElectricMotors•Speedcontrolwithoutimpactpowersupplyquality•Changingarmaturevoltage•Changingfieldcurrent•Restricteduse•Fewlow/mediumspeedapplications•Clean,non-hazardousareas•ExpensivecomparedtoACmotorsDCmotors10©UNEP2006TypeofElectricMotors•Relationshipbetweenspeed,fieldfluxandarmaturevoltageDCmotorsBackelectromagneticforce:E=KNTorque:T=KIaE=electromagneticforcedevelopedatarmatureterminal(volt)=fieldfluxwhichisdirectlyproportionaltofieldcurrentN=speedinRPM(revolutionsperminute)T=electromagnetictorqueIa=armaturecurrentK=anequationconstant11©UNEP2006TypeofElectricMotors•SeparatelyexcitedDCmotor:fieldcurrentsuppliedfromaseparateforce•Self-excitedDCmotor:shuntmotor•Fieldwindingparallelwitharmaturewinding•Current=fieldcurrent+armaturecurrentSpeedconstantindependentofloaduptocertaintorqueSpeedcontrol:insertresistanceinarmatureorfieldcurrentDCmotors(RodwellInt.Corporation,1999)12©UNEP2006TypeofElectricMotorsSelf-excitedDCmotor:seriesmotorDCmotors(RodwellInt.Corporation,1999)•Fieldwindinginserieswitharmaturewinding•Fieldcurrent=armaturecurrent•Speedrestrictedto5000RPM•Avoidrunningwithnoload:speeduncontrolledSuitedforhighstartingtorque:cranes,hoists13©UNEP2006TypeofElectricMotorsDCcompoundmotorDCmotorsFieldwindinginseriesandparallelwitharmaturewindingGoodtorqueandstablespeedHigher%compoundinseries=highstartingtorqueSuitedforhighstartingtorqueifhigh%compounding:cranes,hoists14©UNEP2006TypeofElectricMotors•Motorsarecategorizedonthebasisofinputsupply,constructionandoperationprincipoles•TEXTClassificationofMotorsElectricMotorsAlternatingCurrent(AC)MotorsDirectCurrent(DC)MotorsSynchronousInductionThree-PhaseSingle-PhaseSelfExcitedSeparatelyExcitedSeriesShuntCompound15©UNEP2006TypeofElectricMotors•Electricalcurrentreversesdirection•Twoparts:statorandrotor•Stator:stationaryelectricalcomponent•Rotor:rotatesthemotorshaft•Speeddifficulttocontrol•Twotypes•Synchronousmotor•InductionmotorACMotors(IntegratedPublishing,2003)16©UNEP2006TypeofElectricMotors•Constantspeedfixedbysystemfrequency•DCforexcitationandlowstartingtorque:suitedforlowloadapplications•Canimprovepowerfactor:suitedforhighelectricityusesystems•Synchronousspeed(Ns):ACMotors–SynchronousmotorNs=120f/PF=supplyfrequencyP=numberofpoles17©UNEP2006TypeofElectricMotors•Mostcommonmotorsinindustry•Advantages:•Simpledesign•Inexpensive•Highpowertoweightratio•Easytomaintain•DirectconnectiontoACpowersourceACMotors–Inductionmotor18©UNEP2006TypeofElectricMotorsComponents•Rotor•Squirrelcage:conductingbarsinparallelslots•Woundrotor:3-phase,double-layer,distributedwindingACMotors–Inductionmotor•Stator•Stampingswithslotstocarry3-phasewindings•Woundfordefinitenumberofpoles(AutomatedBuildings)19©UNEP2006TypeofElectricMotorsACMotors–InductionmotorHowinductionmotorswork•Electricitysuppliedtostator•Magneticfieldgeneratedthatmovesaroundrotor•CurrentinducedinrotorElectromagneticsStatorRotor•Rotorproducessecondmagneticfieldthatopposesstatormagneticfield•Rotorbeginstorotate(Reliance)20©UNEP2006TypeofElectricMotorsACMotors–Inductionmotor•Single-phaseinductionmotor•Onestatorwinding•Single-phasepowersupply•Squirrelcagerotor•Requiredevicetostartmotor•3to4HPapplications•Householdappliances:fans,washingmachines,dryers21©UNEP2006TypeofElectricMotorsACMotors–Inductionmotor•Three-phaseinductionmotor•Three-phasesupplyproducesmagneticfield•Squirrelcageorwoundrotor•Self-starting•Highpowercapabilities•1/