ch08

Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-0PowerPointSlidestoaccompanyElectricMachineryFourthEditionStephenJ.ChapmanChapter8Single-PhaseandSpecial-PurposeMotorsCopyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.Schematicviewofasingle-phaseinductionmotor.Figure9.19-1Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-2Torque-speedcharacteristicofasingle-phaseinductionmotor(a)onthebasisofconstantforwardandbackwardfluxwaves,(b)takingintoaccountchangesinthefluxwaves.Figure9.2Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-3Split-phasemotor:(a)connections,(b)phasordiagramatstarting,and(c)typicaltorque-speedcharacteristic.Figure9.3Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-4Capacitor-startmotor:(a)connections,(b)phasordiagramatstarting,and(c)typicaltorque-speedcharacteristic.Figure9.4Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-5Permanent-split-capacitormotorandtypicaltorque-speedcharacteristic.Figure9.6Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-6Capacitor-start,capacitor-runmotorandtypicaltorque-speedcharacteristic.Figure9.7Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-7Shaded-poleinductionmotorandtypicaltorque-speedcharacteristic.Figure9.8Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-8Rotorpunchingforfour-polesynchronous-reluctancemotorandtypicaltorque-speedcharacteristic.Figure9.9Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-9(a)Generalnatureofthemagneticfieldintheairgapandrotorofahysteresismotor;(b)idealizedtorque-speedcharacteristic.Figure9.10Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-10Equivalentcircuitsforasingle-phaseinductionmotor:(a)rotorblocked;(b)rotorblocked,showingeffectsofforwardandbackwardfields;(c)runningconditions.Figure9.11Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-11Single-phaseequivalentcircuitsforatwo-phasemotorunderunbalancedconditions:(a)forwardfieldand(b)backwardfield.Figure9.12Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-12Synthesisofanunbalancedtwo-phasesystemfromthesumoftwobalancedsystemsofoppositephasesequence.Figure9.13Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-13Resolutionofunbalancedtwo-phasevoltagesintosymmetricalcomponents.Figure9.14Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-14MATLABplotforPracticeProblem9.3.Figure9.15Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-15Schematicrepresentationofatwo-phaseinductionmotorwithanequivalenttwo-phaserotor.Figure9.16Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-16Permanent-split-capacitorinduction-motorconnectionsforExample9.5.Figure9.17Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-17Time-averagedelectromagnetictorqueversusspeedforthesingle-phaseinductionmotorofExample9.5.Figure9.18Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-18Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.8-18Basictwo-phaseVRMs:(a)singly-salientand(b)doubly-salient.Figure8.1Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-19Plotsofinductanceversusmfor(a)thesingly-salientVRMofFig.8.1aand(b)thedoubly-salientVRMofFig.8.1b.Figure8.2Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-204/2VRMforExample8.1.Figure8.3Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-21(a)L11(m)versusm,(b)dL11(m)/dmversusm,and(c)torqueversusm.Figure8.4Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-22Cross-sectionalviewofa6/4three-phaseVRM.Figure8.5Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-23A4/2VRMwithnonuniformairgap:(a)exaggeratedschematicviewand(b)plotsofL(m)anddL(m)/dmversusm.Figure8.6Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-24Schematicviewofafour-phase8/6VRM.Polelocationsareindicatedbyarrows.Figure8.7Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-25Schematicviewofathree-phasecastleatedVRMwithsixstatorpolesandfourteethperpoleand28rotorpoles.Figure8.8Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-26IdealizedinductanceanddL/dmcurvesforathree-phase6/4VRMwith40°rotorandstatorpoles.Figure8.9Copyright©TheMcGraw-HillCompanies,Inc.Permissionrequiredforreproductionordisplay.9-27IndividualphasetorquesandtotaltorqueforthemotorofFig.8.9.EachphaseisexcitedwithaconstantcurrentI0onl