外文翻译双闭环直流调速系统的说明.docx
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外文翻译双闭环直流调速系统的说明
DoubleLoopDCSpeedControlSystemDescription
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DoubleLoopDCSpeedControlSystemDescription
Ⅰ.systemanalysisandsynthesis
1.Analysis
(1)Inthespeedandcurrentdualclosed-loopspeedcontrolsystem,inordertochangethemotorspeed,whatparametersshouldberegulating?
ChangespeedregulatorKnmagnificationwork?
PowerelectronicconvertertochangethemagnificationfactorKswork?
Changethespeedofthefeedbackcoefficientofwork?
Tochangethemotor'sstallcurrentsystemshouldadjusttheparametersofwhat?
A:
Tochangethemotorspeed,changespeedregulatorKnmagnificationandpowerelectronicconverterswillnotworkmagnificationfactorKs,stablewhenn=Un=Un*,sotheonlychangeinthevalueofagivencoefficientofUn*andfeedbackbefore.Tochangethemotor'sstallcurrent,onlyneedtochangethesamevaluegivenUim*andfeedbackcoefficient,becausethestability,Uim*=Idm,canbedrawnfromthetype
(2)Speed,thecurrentdoubleclosed-loopspeedcontrolsystemwhenthesteady-stateoperation,thetworegulatorinputvoltageandoutputvoltagedeviationisthenumber?
A:
Thespeedandcurrentdualclosed-loopspeedcontrolsystemwhenthesteady-stateoperation,thetworegulatorsaretheinputbiasvoltageiszero,bytheformulan=Un=Un*,n=n;Uim*=Idm,Idm=Idl.
(3)Inthespeedandcurrentdualclosed-loopspeedcontrolsystem,thetworegulatorsarePIregulator.Whenthesystemisrunningwithratedload,thespeedfeedbacklinesuddenlydisconnected,thesystemre-enterthesteady-state,thecurrentregulatoristheinputbiasvoltagetozero?
Why?
A:
Whenthesystemisrunningwithratedload,thespeedfeedbacklinesuddenlydisconnected,thenUn=0,=Un*-Un=Un*,sothatUitoreachUim,0,rateofincreaseinn,whenthesystemafterre-enteringthesteady-state,thatis,Id=Idl,then,=Uim*-Idl0,arenolongerchanges,changesinrotationalspeednisnolonger,butatthistimethantherotationalspeednatthetimeofthefeedbacklinespeedtobreakbig.
(4)Whyisthespeedwithintegralcontrolsystemisnotstaticpoor?
A:
Speedregulatorintegralsystem,toachievenon-staticerrorisduetothecharacteristicsofintegralcontrolregulator,thatis,theaccumulationofpointsandtheroleofmemory.
(5)Double-loopspeedcontrolsystem(PI),loadchanges,Idl>Idm,askedbicyclolspeedcontrolsystemASRandACRhow-conditioning,theresult?
A:
Whentheloadchanges,Idl>Idm,speeddecreasedrapidly,thecurrentIdsoontoIdm,andoflimitedamplitude,rapidrateofASRsaturation,ACRhasbeenlimitingconditions,toformablockingphenomenon,long-runningwilldamagethesystem.
2.System
SpeedregulatorandcurrentregulatorintheDoubleLoopDCMotorControlSystemcanbesummarizedasfollows:
(1).Theroleofspeedregulator
Speedregulatorisaspeedcontrolsystemofthedominantregulator,whichallowsspeednwillsoonchangewithagivenvoltageUn*changesinsteady-statespeederrorcanbereduced,ifthePIregulatorcanachievethenon-staticerror.
1)Theeffectofloadchangesintheroleofanti-disturbance.
2)Theoutputamplitudeofthedecisionlimitthemaximumallowablemotorcurrent.
(2)Theroleofcurrentregulator
1)Asaregulatoroftheinnerring,outerringatthespeedoftheadjustmentprocess,itmakesthecurrentcloselyfollowedthegivenvoltageUi*(thatis,theouterringmodulatoroutput)changes.
2)Fluctuationsinvoltagefromtheroleofdisturbancerejectionintime.
3)Thespeedofthedynamicprocessofensuringthatthemaximumallowablemotorcurrent,therebyspeedingupthedynamicprocess.
4)Whenthemotoroverloadorstallwhenthearmaturecurrentlimitofthemaximum,automaticprotectionfromtheroleofacceleration.Oncethefaultdisappears,thesystemautomaticallyreturntonormal.Yesterday,theroleofthereliableoperationisveryimportant.
Ⅱdouble-loopspeedcontrolsystemcommonfaultsanalysis
1.Introductionofasystem
(1).Double-loopspeedcontrolsystemcomponentsinFigure1.1Currentloop:
fromthecurrentregulatorLT,triggerCF(inputtransformationfortheCSR),silicon-controlledrectifierbridge,motorarmatureandcurrentlooptransformLBcomponent.thespeedofouterring:
thespeedregulatorfromST,currentloop,suchaslinkinertia,motorandloadmomentofinertiaandthespeedoftransformationcomponentsSB.inthedouble-loopspeedcontrolsystem,thespeedofthedecisionloopoftherunningcharacteristicsofthewholesystemandstability,andplayaleadingrole,andtochangethecurrentringplaystheroleoftheinternalstructureofthesystemisdependent,butsinceitisasawholetoparticipateintheclosed-loopspeedtothespeedofadirectimpactontheworkoftheclosed-loop,itmustfirstgooddebuggingcurrentloop,andthentestingthespeedofouterring,sothatthewholesystemhasgooddynamicperformance.
(2).Double-loopspeedcontrolsystemofthetypicalworkingcondition
1)Start(orthespeed):
STinthestart-upprocesshasbeensaturated,sothatthespeedofthisloopintheequivalentopen-loopstate.Systemonlyintheconstantcurrentloopundertheregulationtoensurethemotorataconstantcurrentofthemaximumallowableunderthestart-up.
Figure1double-loopspeedcontrolsystemstructure
2)slowdown(orstop):
STatthistimetoreachtheoutputamplitudeofthereverselimit.Maincircuitcurrentbythebridgeisreducedtozeroaftertheinverter.LTandCSRoutputwillsoonreachthemaximumreverse.CFpulseoutputtoreachβmin,currentloopforopen-loop.motortorqueunderdecelerationuntilthemotorspeedclosetothegivennewvalue,currentloopandspeedlooponeafteranotherintotheclosed-loopwork,motorinthenewvalueofagivenrun.
3)Gridvoltagefluctuation:
Thismotorbecauseofthelargermomentofinertia,whichcausedthefirstchangeinarmaturecurrent,SToutputalsodidnotchangetheeffectofcurrentloop,LTrapidlychangingtheoutputsothatangleαbeadjustedquickly,sotheimpactonthespeed.
4)Smallchangesinload:
intheoperation,loadchanges,willcausethemotorspeeddeviationfromthegivenvalue.speeduptherecoveryprocessandtheaforementionedspeed(ordeceleration)issimilartotheprocess.
2.CommonFaultAnalysisandProcessing
(1)Thenormalsupplyvoltage,thyristorrectifieroutputwaveformarrhythmiacausedbythisphenomenonisduetotriggersawtoothslopecausedinconsistency.Sawtoothslopeadjustpotentiometer,theoutputwaveformuniformitycouldbeachieved.intheadjustmentprocesstostrikeabalancebetweenQi,thispointshouldbepaidattentiontotheactualdebugging.
(2)DCMotorAnalysisofmechanicalpropertiesofsoftthyristorDCmotorsystem,whenthecurrentintermittentmechanicalpropertieswhenthefirstno-loadspeedischaracterizedbyhighideals,andthesecondischaracterizedbymechanicalpropertiesofsoft.Theso-calledmechanicalfeaturessoft,thatis,smallchangesinloadwillcausegreatchangesinspeed.oscilloscopetoobservewhenusingthebridgerectifieroutputwaveform,onemayfindthatmissingrelative.atthistimeneedtocheckwhetherthetriggerhaspulseoutput,fastwhetherthefusemelting,whetherthebreakdownorthyristorcircuit,synchronoustransformerisdamaged,whetherthelackofpower.toidentifytheproblems,canberesolved.
(3)Thespeedofthespeedofinstabilitycausedbymanyfactorsofinstability:
1)Electricgunsarenotfirmlyfixedorwiththehostofdifferentaxis.
2)Theparametersofthespeedregulatorinappropriate.Respondtothedynamicparameterstoadjust(changetheratioofintegralparameters).
3)Ofaspeedcontrolsystemthereare(orbad)
4)Maybecausedasaresultofinterference.shouldbefoundtointerferewiththereasonsfortakinganti-jammingmeasures.
(4)Alittletothesetratedmotorspeedishigherthanthatshouldfirstcheckwhetheritisnormalfortheexternalcontrolsystem,suchasoutsidethenormalcontrolsystem,itmaybegivenpoints,speedregulator,currentregulator,suchascausedbylinkfailure.Shouldbecutoffthemaincircuitpowersupply,onlythecontrolsystemtotheelectricity,notagiveninthecase,testingeachofthekeypoints(suchasthecurrentregulator,voltageregulator,etc.ofthepotential.andthengiventogetherwiththeformertoonebyoneaftereachofthekeypointstocheckthepotentialchanges,youcanfindoutthefaultlies.
(5)Bridgerectifieroutputvoltageisnothighstressed
1)thespeedregulatorandcurrentregulatorlimitertoosmall,shouldbeliberalized
inaccordancewithappropriateamplitudethreshold.
2)thanthespeedfeedbacksignal,inthattheycanreducetherateofappropriatefeedbacksignals.
(6)Tothetimingsystemstillintheabsenceoflow-speedoperation(thatis,thephenomenonofemergenceofreptiles)Thisisbecausethesystemof"zerodrift"causedby.Whentheinputsignaliszero,theoutputvoltagebytheinputamplificationstageoftheoffsetpotentiometerdecisionscanbeoffsetbyadjustingthepotentialallowsα=90°,atthistimetozerooutputvoltagerectificationsystem,theelectricalwillnotcrawl.
(7)Withagivensystemcannotrun
Shouldfirstcheckwhetheritisnormalfortheexternalcontrolsystem,suchasoutsidethenormalcontrolsystem,itmaybegivenpoints,speedregulator,current
regulator,suchascausedbylinkfailure.Shallbecutoffmaincircuitpowersupply,onlythecontrolsystemtotheelectricity,notAddthegivencircumstances,thekeypointsofeachtest(suchasthecurrentregulator,voltageregula