外文翻译原文-晶体管开关的直流电机调速控制

TRANSISTORIZEDSWITCHINGCONTROLOFAVARIABLE-SPEEDDCMOTORTransistorizedSwitchingControlofaVariable-SpeedDCMotorJACKALLISONtANDPAULVERGEZt,MEMBER,IRESummary-_Whereadcmotorissuppliedenergyfromastor-zagebatteryorotherfixedvoltagesource,variable-speedooperationisusuallyaccomplishedbyaddingresistanceinI)serieswiththemotorsupply.Inthistypeofcontrol,only3partofthetotalenergydeliveredbythesourceisavailableRatthemotortodousefulwork.ThebalanceoftheenergyRsERGYUTILtZED,isconvertedintoheatbytheseriesresistanceandislost.MOTORSPEEDAmoredesirableapproachtospeedcontrol,aspresentedinthisreport,istoinsertaswitchratherthanaresistorinserieswiththemotorssupply.Heretheswitchwouldbeopenedandclosedatregularintervalswhichwouldrepre.(a)sentinfiniteorzeroseriesresistance,respectively.Ineitherstate,theswitchwouldpresentnoenergylossestothecircuit.ThemotorspeedvarieswiththepercentageofLOADtimetheswitchremainsclosed.Thelattersystemhastheadvantagethatforagiven(b)speedsetting,variationsinloadwillnotcausefluctuationsFig.1-Speed-loadandenergydistributioninbasicspeedinspeedduetoIRdropinanyseriesresistor.controlcircuit.Thetransistorizedswitchingcircuitdescribedindetailinthisreportrepresentsanefficientmethodofswitchingthemotorsupplycurrentforgoodspeedcontrol.Thelabo.controllesinthefactthatthepotentialdroacrossratorymodel,whichgaveverysatisfactoryperformance,theresistancewillcausepoorspeedregulationwithwasdesignedtocontrol20amperesat24volts,orapproxi-respecttovaryingloads.Fig.l(b)showsaplotofamatelyaone-halfhorsepowermotor.Thisratingmaybein-typicalspeedvsloadcurveforaseries-woundmotorcreasedwithonlyminormodificationstothecircuit.whichiscontrolledbyaseriesrheostat.AmoredesirablemethodofspeedcontrolinvolvesMOTORCONTROLS-PRESENTANDPROPOSEDtheuseofaperiodically-operatedswitchinsertedintheplaceoftheseriesrheostat.Thecontinualopen-Aseriesdcmotorisusedinapplicationswhereingandclosingoftheswitchregulatestheinputtothevariable-speedoperationandhighstartingtorquearemotor;variationofthetimedurationoftheONandrequired;varioustechniquesprovideforspeedcontrolOFFpositionsoftheswitchprovidesacontroloftheofadcmotorinsuchapplications.Eachofthesespeedofthemotor.Fig.2showsthetimerelation-techniquesisbasedonacommonprinciple-regulat-shipbetweentheOFFandONpositionsofsuchaingthespeedofthemotorbycontrollingtheinputswitchforvarioussettingsofmotorspeed.Oneofthepowertothemotor.mainadvantagesofthissystemisanefficientutiliza-Themostcommonmethodofcontrollingthespeedtionoftheavailablepower;theswitchhasveryhighofaseriesmotorisavariableresistorinsertedinseriesimpedancewhenopenandaverylowimpedancewhenwiththemotor.Thismethodisparticularlyapplicableclosed.Fig.3(a)indicatestherelationshipbetweenwhentheavailablepowersupplyconsistsofaconstantmotorspeed,energylostandenergysuppliedtothevoltagesource,suchasastoragebattery.Thepowermotorwhenaswitchingcircuitisusedtocontrolthesuppliedisdividedbetweenthemotorandtheseriesspeedofaseriesmotor.Thespeedregulationofaresistor,withtheresultingdisadvantagethatthesystemsystemusingaswitchasaspeedcontrolwouldbeim-isinefficientwhenthepowerlossintherheostatisprovedoverthatofasystemusingaseriesresistancehigh.Fig.l(a)illustratestherelationshipbetweencontrol,since-thevariationinpotentialdropacrossspeed,energylostbytheseriesresistance,andenergytheswitchwouldhaveanegligiblevariationwithloadsuppliedtothemotorwhenarheostatisusedinseriescurrent.F;g.3(b)isaspeed-regulationcurveforawithamotortocontrolmotorspeed.Anotherdisad-motorwhichusesaswitchforspeedcontrol.vantageintheuseoftheseriesresistancetypeofCIRCUITOPERATION*ReceivedbythePGIE,August22,1960;revisedmanu-Poetrnitrcaalfhg-oewthnscriptreceived,March11,1961.Poernstrcablofhg-wrswcigtTexasInstruments,Inc.,Dallas,Tes.withverylowdissipationlossesarenowmass-pro-19IRETRANSACTIONSONINDUSTRIALELECTRONICSPOWERONtrolsthepowerlevelofthedriverstageundervarying|MAX.loadconditionssothatahighsystemefficiencycanPOWEROFFSPEEDbemaintained.TherequiredON-OFFcyclingopera-TIIME_-_ItionofthedriverstageandthecontrolofthedutyONcycle(ratioofONtimetototaltime)ofthepowerswitchiscontrolledbyavariableresistorinthemulti-HIGHvibrator.ThemultivibratoralsoestablishestheperiodOFF_uSPEEDoftheswitchingcycle.IIFig.5isacompleteschematicofthespeed-controlONsystem.ArectifierandacondenserwereplacedinMED.parallelacrossthemotortominimizethepossibilitySPEEDofdamagetothepowertransistorswhentheyswitchOFF_offtheheavilyinductivemotorload.IftherectifierIandthecondenserwerenotpresentinthecircuit,aON-highvoltagewouldappearacrossthepower-switchSLOWstageduringturn-offduetothereversevoltagein-SPEEDducedinthemotorwindingswhenthecurrentisin-OFFterrupted.Thehighvoltageappearingacrossthe1/100transistorsinthepower-switchstagecouldeasilySECFig.2-Speedcontrolbymeansofpulse-widthvariation.OSCILLATORduced.Thesetransistorsarecapableofhandlingthousandsoftimesthepowerrequiredfortheircontrol.Thus,itispossibletodesignatransistorizedswitch-SPEEDPOWERingcircuit,whichwilloffertheadvantagesdiscussedCONTROLDRIVERSWITCHLOADintheprecedingparagraph,controllingthespeedofaseries-wounddcmotor.Fig.4isablockdiagramofsuchacircuit.ThissystemwasdesignedtocontrolthespeedofaAUDRIC20-ampere24-voltdcseriesmotorwithpeakcurrentsCONTROLupto100amperes.Thepower-switchstageofthecir-Fig.4-Blockdiagram.cuitcontrolsthepowerwhichisdeliveredtothemotor,whilethedriverstageservesasacurrentam-plifier,whichfurnishessufficientcurrenttodrivethereachthebreakdownvoltageratingandmightdamagepowerswitch.Theautomaticdrive-controlstagecon-thetransistors.Iftherectifierisaddedtothecircuit,thenthevoltageacrossthetransistorduringtheswitch-offcyclewillbelimitedtothesupplyvoltage.zPathsABCorADEofFig.6(a)wouldbefollowedby-2ENERGYLOSTtheoperatingpointofthepowertransistorsduringtheTASISTORw:SWITCHzWcoswitch-offcycle.ThepathtakenbythetransistorsSPEEDENERGY1|u/woulddependonthesupplyvoltage,VccjorVcc2,CNSPEEDUTILIZEDwhichisbeingusedbythesystem.However,thecur-MMOTORSPEEDrentwhichflowsinthepowerswitchduringtheONcycleofoperationcannotchangeinstantaneously,duetothefiniteturn-offtimeofthetransistorsandthein-(a)WIductanceofthemotorwinding.SincethecurrentwhichIisflowingthroughthetransistoratthistimewillbel_nearlyequaltothehighcurrentwhichflowedduringLOADtheONcycle,thetransistorwillbeinaveryhighdis-(b)sipationregionofthetransistorcharacteristicandFig.3-Speed-loadandenergydistributionforswitchedoverheatingofthepowertransistorsmightoccur.Thecircuitcontrol.possibilityofdamagetothetransistorsisminimized20TRANSISTORIZEDSWITCHINGCONTROLOFAVARIABLE-SPEEDDCMOTORAUTOMATICIIIaSPEEDOSCILLATORDRIVERDRIVEPOWERSWITCH+24VdcMOTORasPEEDCONTROLICONTROL101IK100|RIR2R3R4S0X5wCI223,I12w6p500I2N13732N10382000601I0203040.5efCnrEfROQI2N511Il2N1372I191A50looC)III2Nl372082N1372I5002700C300Q200I401KI1KampdII05w20wI20wvd*SpeedControlElementRI-R4ALL0.050)01-Q4ALL2N54SFig.5-Completeschematicofspeed-controlsystem.bytheadditionofacapacitor1inparallelwiththeciency,butprovidesbetterequalizationofcollectorrectifierandthemotor.Thecapacitorvoltageopposescurrents.thesupplyvoltageduringtheswitch-offcycle,thusAfactortobeconsideredwhentransistorsareusedallowingthecurrentthroughthetransistortodropinswitchingcircuitsisthatthetransistorsmustre-withoutthesuddenvoltageriseacrossthetransistor.maininasaturatedstatewhilehandlinglargecur-Theaddedcapacitanceallowsthelocusoftheoperat-rentsinordertokeepthetransistorpowerdissipationingpointofthetransistorsinthepower-switchstagetoaminimum.ThelocusoftheoperatingpointofatofollowpathABorACFig.6(b).Theparticulartransistorusedasasaturatedswitchfallswithinthepathtakenwoulddependonthesupplyvoltage,VcciactiveregionofthetransistorforonlyasmallportionorVcc2,whichcorrespondstothesupplyvoltageofoftheoperatingcycle.Intheactiveregionofthethesystem.transistorcharacteristicswherelineartransistoroper-Thepower-switchstageofthecircuitconsistsofationoccurs,theemitterjunctionisforward-biasedfourparalleled2N514transistors.Foursuchtransis-andthecollectorjunctionisreverse-biased.Asatu-torswerenecessarysincethecurrentrequiredbytheratingtransistorisintheactionregiononlywhilemotorinastartingorstalledconditionapproaches100switchingbetweentheONandOFFlevels.Wheninamperes.2N514transistorsarecapableofcarryingantheONposition,thetransistorhasahighvalueofabsolutemaximumcollectorcurrentof25amperes;collectorcurrent(5-25amps);however,thecollectorspecialprecautionsmustbetakentoassureanequaltoemittervoltage,VCE,isaslowas0.25volts.Thisdivisionofcurrentbetweenthefourpower-switchindicatesthatonlyasmallamountofpowerisdis-transistors.ThemethodtoprovidecompensationforsipatedinthetransistorduringtheONcycle.WhenvariationsinVCE(sat),hFEandforwardtransferad-thetransistorisinanOFFposition,thecollectorcur-mittance(YFE)istheuseofemitterresistors.Therenthasaverysmallvalue.Therefore,eventhoughvalueofresistorsisacompromisebetweenefficiencythecollectortoemittervoltagehasavalueequaltoandcurrentdistributionoftheparalleledtransistors.thesupplyvoltageatthispoint,thepowerdissipatedIncreasingthisresistorvaluereducesthecircuiteffi-duringtheOFFcycleisextremelylow.Whenthe_operatingpointiSintheactiveregionofthetransistor1A.F.Newell,Anintroductiontotheuseoftransistorscharacteristics,bothVCEandIchavesignificantinductivecircuits,MullardTechnicalCommun.,vol.4,values,andthepowerdissipatedismuchgreaterthanpp.157-160;November,1958thedissipationineithertheONorOFFposition.21IRETRANSACTIONSONINDUSTRIALELECTRONICSVCECOLLECTOR-EMITTERVOLTAGEthelargestanticipatedvalueofIcinconjunctionwithVcc2VccithelowestvalueofhFE.IfIBshouldfailtohavesuf-ficientmagnitudetokeepthetransistorinasaturatedstate,theresultingincreaseinpowerdissipationcouldexceedthetransistorspowerrating.However,B=o0IICifIBismaintainedatavaluecorrespondingtotheCOLLECTORCURRENTlargestanticipatedvalueofIC(max)/hFE(min),ineffi-ciencywouldresultinthedriverstagewhenmoderatevaluesofIcarerequired(correspondingtonormalDoperationofthemotor).ProvisionshouldbemadetoBAlallowautomaticvariationinIBwhenIcisvaried.Thisautomaticvariationhasbeenaccomplishedin(a)thespeed-controlsystembytheadditionoftheauto-Vcc2Vcc,maticdrive-controlcircuit(seeFig.7).Theauto-|BXImaticdrive-controlstage,representedbyQ6,Q7,Q8andQ9,sensesanydifferenceinVCEofQ6andthepower-switchtransistors.Iftheparalleled2N514transistorsinthepower-switchstagearenotinsatu-=oICrationduringanyportionoftheONcycleofoperation,COLLECTORCURRENTthebasevoltageofQ7willbecomenegativewithre-specttoitsemittervoltage,andthetransistorsQ8andQ9willbegintoconduct.Thisconductionwill1Acausemorebasecurrenttoflowintothepower-switch(b)stageofthecircuit,drivingthatstagebackintosaturation.Fig.6-Switchofflocus-inductiveload.Fig.8consistsofphotographsofthecollectorvoltageandcurrentwaveformsforthepower-switchTherefore,iftheONandOFFcyclesfalloutsidethestageofthecircuitforvariousconditionsofmotoractiveregionofthetransistor,theaveragepowerdis-speedatanintermediateload.Fig.9isaphotographsipatedbythetransistorwillbeminimized.ofthecollectorcurrentandvoltagewaveformsofaIfasaturatedconditionistobemaintainedoverasingletransistorinthepowerswitchunderastalledwiderangeofcollectorcurrentvariations,IB,theconditionofmotoroperation,withtheautomaticdrive-basecurrentmustbesufficientlylargetoaccommodatecontrolstageremoved.ThewaveformsshowninFig.QRIVERIAUTOMATICDRIVECONTROL|POWERSWITCH+24VDCoQ50.05Q0.05Q2N511IVARIABLEPULSE|1WIDTHINPUT!92N511Q60203,042N5142N51407_RILOADFig.7-Automaticdrive-controlcircuit.22TRANSISTORIZEDSWITCHINGCONTROLOFAVARIABLE-SPEEDDCMOTOR20AMPSVTSLOWSPEED6010AMPSbCOLLECTOR-0._.CURRENT_DJ20VOLTSC-.OLLECTORTOTRANSISTORSWITCH-O_EMITTERVOLTAGER_HEOSTAT_/SWEEP-0-2millisec/cm/400Ft20AMS-MEDIUMSPEED-_20OAMPSCOLLECTOR3000mttttCURRENTD/20VOLTS-=-COLLECTORTO0_|IIEMITTERVOLTAGEg/9|/oSWEEP-2miIIisec/cm200/HIGHSPEEDFIJjr.,k20AMPSHIHSED101|/|;10AMPSCOLLECTOR0-4.O.CURRENT-20VOLTS|-|COLLECTORTO0SWEEP-2millisec/cmEMITTERVOLTAGE0-Fig.8-Collectorcurrentandvoltagewaveforms.Fig.11-Controlelement-poweroutvspowerin(speedconstant).MOTORSTALLED20AMPSThecircuitcomponentwhichcontrolstheratioof10AMPSCOLLECTOROFFandONtimeforthepowerswitchisthe50K-ohm0.CURRENTvariableresistorinthemultivibrator.Theextreme20VOLTS-COLLECTORTO20VOCOLLEMITTERVOLTAGEsettingsofthevariableresistorwillcausetheswitch-SWEEPp-2millisec/cmingactiontoceaseandthepowerswitchwillbeeitherFig.9-InstantaneouscurrentandvoltageforstalledfullONorOFF.Intermediatesettingswillestablishcondition.thepulsewidth,andthereforethepercentageofONtimeforthepowerswitch.Theoperatingfrequencyof9indicatethattheinstantaneouspowerdissipatedinthemultivibratorisapproximately100cps.thetransistorattheendoftheONcycleis240watts.Automaticdrivecontrolisanecessityifthishighdis-CONCLUSIONSANDRECOMMENDATIONSsipationistobeavoided.sipatheniswitchiactiond.ofthesystemisprovidedbyThesystemdescribedintheprecedingsectionwasTheswthnacioofthsysteisroviedbquantitativelycomparedwiththeseriesrheostattech-amultivibrator(Q1OandQll),whichholdsthedriverstageeitherinfullsaturationorcompletelyOFF.Thus,thedriverstageofthesystemisoperatedatalowpower-dissipationlevel.22D-TRANSISTORSWITCH24C0.-EOSTTt1wml!-1WjjIEoolfj1w-18CC-.-.160-4/23oc-A-01200ee-.-.-60-RHEOSTAT-01IRETRANSACTIONSONINDUSTRIALELECTRONICSniqueofspeedcontrol.Fig.10showsasetofspeed-moreefficientthanthesystemwhichusedaseriesregulationcurvesforthreedifferentsettingsoftherheostatforspeedcontrol.rheostatandforthreeequivalentsettingsofthetran-Thecircuitpresentedinthisreportwasdesignedsistorizedswitchingcircuit.Theregulationcurvefortofunctionat24volts,andtosupplyacurrentwhichthesystemwhichusestheswitchingcircuitcloselyapproaches100amperes.Withminormodifications,approachesthatofthemotorusedinthesystem.thecircuitisflexibleenoughtoworkinanumberFig.11isacomparisonofpower-outvspower-inofapplicationswhichmightrequirelowerorhigherforthreedifferentspeedsettingsofthecontrolele-voltages.Thecurrentswitchingcapacityofthecir-ment.Fig.12isaplotofpower-outvspower-inforcuitislimitedonlybythenumberoftransistorsthecompletesystemunderthesamecircumstances.whichareparalleledinthepower-switchstageandThecurvesindicatethatthesystemwhichusedthethemaximumcurrent-carryingcapacityofeachofthetransistorswitchforspeed-controlpurposesismuchtransistors.ATransistorizedTensionandLoopControl*T.E.DeVINEYtSummary-Withtheintroductionofpowersemiconductors,itrectifierbridgeandamagnetic-amplifierfiringcircuitispossibletoaccomplishmanyfunctionsstaticallythatweredesignedtobeusedasanadjustablemotorwerepreviouslyaccomplishedwithelectro-mechanicalde-field-powersupply;andauniquephotoelectricloopvices.Theuseofstaticcomponentsresultsinimprovedperformancewithreducedmaintenance.Thetensionandloopcontroldescribedinthispaperfeaturestheuseofmaterialloopingintothepit.staticcircuits.Thepaperdiscussesthesystemdesign,thecom-ponentsandtheirfeatures,andtheproblemsen-INTRODUCTIONcounteredintheirapplication.Thiscontrolwasdesignedforasteel-stripweldingCIRCUITCOMPONENTSandcoilinglineshowndiagrammaticallyinFig.1.ThepurposeoftheprocessinglineistoweldsmallSiliconControlledRectifierBridgeandFiringCircuitcoilsintolargercoils.Threelargedcdrivemotorsareu