Battery monitor for electric vehicles.docx

UnitedStatesPatent叫Kopera54)BATTERYMONITORFORELECTRICVEHICLES751Inventor:JohnJ.C.Kopcra,RochesterHills,Mich.73Assignee:ChryslerCorporation,AubumHills,Mich.21Appl.No.:820,749221Filed:Mar.19,1997RelatedU.S.ApplicationData62DivisionofSer.No.369,250,Jan.6,1995,Pat.No.5,646,534.51 Int.CL6GOlR31/36;GOIN27/41652 USCl324/434;324/42858FieldofSearch324/426,427,324/428,431,434;320/48;340/636U.S.PATENTDOCUMENTS3.307.1012/1967Byles324/4294,360,76611/1982Bogardus.Jr318/1394.401,9428/1983Renz324/42756ReferencesCited4.484,14o11/1984Dieu324/4344.590.4305/1986Vandenbergheetal324/4274,633,41812/1986Bishop364/5544.931,7386/1990MacIniyreelal324/4355,111,1325/1992Motose322/905,170,12412/1992Blairetal324/4345.250,90410/1993Salanderetal324/4305.270,94612/1993Shibasakietal364/4925,321,6276/19%Reher364/4835,345.3929/1994Mitoetal364/483US(X)5808469AiiPatentNumber:455,808,469DateofPatent:Sep.15,19985.444,3788/1995Rogers324/4285,546.0038/1996Noworolskie(al324/4345.602,4812/1997Fukuyama324/4345.619.4174/1997Kendall364/4835J05.9291/1998Caravelloelal324/4345.712.5681/1998ohreial324/434PrimaryExaminer-IennW.BrownAttorney,Agent,orFinnarkP.Calcaterra57ABSTRACTAbatterymonitorformonitoringthevoltageandtemperatureof(hebatteriesassociatedwithabatterypackofanelectricvehicle.Thebatterymonitorincludesanoptoisolatorthatelectricallyseparatesanisolatedportionofthebatterymonitorconnectedtothebatteriesfromanonisolatedportionofthebatterj,monitor(hattransmitsbatteryvoltageandtemperaturesignalstoavehiclecontrolleroftheelectricvehicle.Thebatterymonitorispositionedproximatetoabatteytubholdingthebatteriesoftheelectricvehiclesothathighvoltagewiresconnectedtothebatterieswithin(hebatterytubarelimitedinlengthforsafetypuoses.Further,alimitednumberofwirestransmittingthebatteryvoltageandbatterytemperaturesignalsfromthebatterymonitortothevehiclecontrollerarerequired.Thebatterymonitorcanincludeamultiplexer(hatselectivelytransmitsthebatteryvoltageandtemperaturessignalstotheoptoisolatorinacontrolledmanner,orcanincludeaseriesofotheropto-isolatorsthattransmithighpowerbatterysignalstoacapacitortobechargedwhere(hechargeonthecapacitorisrepresentativeofthevoltageofaparticularbatterjf.20Claims,2DrawingSheets30io-f-fmco16A/D8USMUXCHANNEL!SftfCTaSWTCHSTLECT+f5V.+5V.-15V.Otf,48AMPIfSOUTORS1*rADDRESSMJCRoPRoCESSOR4TEMP.4046BATTERYTUBCOMMONTEMP.X5141610/°ATTENUATORDIFF.48AMP?“0-IOPTOOo 02 73254BUFFERSA/DISOLATORSTEMP.CoMMoN36MUXCHANNELSELECT&SWITCHSELECT60>powERisuppiy+5v-INFILTERXIO68,66+15V+5V15VBUSJ1QQDQ长12213020Kn8090128TEMP.X5!MUXOPTOISOLATORSXlO100髀ORSdjp102PnFI106108A/DDIFF.114MP,96,ADDRESS=INPUTS9488104TOH2144MICRO120ProcessoRITFig-2140118COMM.BUS15Coo)0BATTERYMONITORFORELECTRICVEHICLESThisisadivisionofU.S.patentapplicationSer.No.08/369,250,filedJan.6,1995,nowU.S.Pat.No.5,646,534.BACKGROUNDOFTHEINVENTION1. FieldoftheInventionThisinventionrelatesgenerallytoabatterymonitorformonitoringthebatteriesofanelectricvehicleand,moreparticularly,toabatterymonitorthatmonitorsthevoltageandtemperatureofthebatteriesofanelectricvehiclewherethebatterymonitorispositionedproximate(othebatteries.2. DiscussionoftheRelatedArtTodaythereisagrowingdemandforelectricvehicleswhichrunonelectricpowerstoredinmultiplebanksofbatteries.Increaseduseofelectricvehicleshasbeenfueledbymanyfactorsincludingconsumerdemand,emissionconcernswithinternalcombustionenginesandincreasedgovernmentalregulations.Becauseofanumberofobviousandindustrj,relatedreasons,itisnecessarytomonitorthevoltageandtemperatureofthebatteriesusedbytheelectricvehicles.Asiswellunderstd,itisdesirabletocontrolthechargingofthebatteriesofanelectricvehicle.Toachievetheoptimumandmostrapidchargingrate,(hevoltageandtemperatureof(hebatteriesmustbemonitoredtoinsurethatthebatteriesdonotoverheatduringthechargingprocedure.Further,itisnecessarytomonitorbatterycapacityduringoperationofthevehicletodetermineexistingbatterycapabilities.Conventionalmethodsformonitoringbatteryvoltageandtemperaturehaveseveraldisadvantages.Forexample,typicalbatterymonitoringdevicesformonitoringbatterjrvoltageuseisolationamplifierstoisolate(hebatteryvoltageandassociatedcurrentfromthemonitoringdevice.Theseisolationamplifiersgenerallyusetransformers,whichareheavyandcostly,toachievetherequiredisolation.Also,knownmonitoringdevicesrequiremultiplewiresattached(oeachbatterythatareroutedthroughoutthevehiclepossiblyprovidingelectromagneticcompatibility(EMC)problemswiththevariouselectricalmodulesusedinthevehicle.Inaddition,somemonitoringdevicesutilizecommongroundingschemeswhichconnectthevehicle'ssupplyvoltageforitselectricmodulestothebattery'shighvoltagesystem.Therefore,thebatteriesandtheassociatedhighcurrentsarenotgalvanicallyisolatedfromtheelectricmodulesin(hevehicle.Whatisneededisabatterymonitorforelectricvehicleswhichdoesnotsufferfromtheabove-mentioneddisadvantages.Thiswilleliminatetheuseofcostlytransformers,reduceelectromagneticcompatibility(EMC)concerns,reduceoverallvehiclewiringandisolatethebatteryvoltageandcurrentsfromthevehiclesotherelectricalsystems.Itis,therefore,anobjectofthepresentinventiontoprovidesuchabatterymonitorforelectricvehiclesandamethodtherefore.SUMMARYOFTHEINVENTIONInaccordancewiththeteachingsofthepresentinvention,abatterymonitorisdisclosedtormonitoringthevoltageandtemperatureofthebatteriesassociatedwiththebatterypackofanelectricvehicle.Thebatterymonitorincludesanisolatorthatelectricallyseparatesanisolatedportionofthebatterjfmonitorconnectedtothebatteriesfromanonisolatedportionof(hebatterymonitorthattransmitsbattery2voltageandtemperaturesignalstoavehiclecontrolleroftheelectricvehicle.Thebatterymonitorispositionedproximatetoabatterjftubholdingthebatteriesoftheelectricvehiclesothathighvoltagewiresconnectedtothebatterieswithin(hebatterytubarelimitedinlengthforsafetypurposes,andalimitednumberofwirestransmittingthebatteryvoltageandbatterytemperaturesignalsfromthebatterjfmonitortothevehiclecontrollerarerequired.Inoneembodiment,anattenuatorandmultiplexerselectivelytransmitthebatteryvoltageandtemperaturesignalstoasingleopto-isolatorinacontrolledmannertobetransferredtothevehiclecontroller.Inanalternateembodiment,aseriesofopto-isolatorstransmitahighvoltagebatterysignaltoacapacitortobecharged,andasingleopto-isolatortransfersthechargefromthecapacitortothevehiclecontrolleronthenon-isolatedsideofthebatterymonitor.BRIEFDESCRIPTIONOFTHEDRAWINGSStillotheradvantagesofthepresentinventionwillbecomeapparenttothoseskilledintheartafterreadingthefollowingspecificationandbyreferencetothefollowingdrawinginwhich:FIG. 1 isaschematicblockdiagramofabatterymonitoraccordingtooneembodimentofthepresentinvention;andFIG. 2 isaschematicblockdiagramofabatterymonitoraccordingtoanotherembodimentofthepresentinvention.DETAILEDDESCRIPTIONOFTHEPREFERREDEMBODIMENTThefollowingdescriptionofabatterymonitorformonitoringthebatterytemperatureandvoltageofabatterypackinanelectricvehicleismerelyexemplaryinnatureandinnowayisintendedtolimittheinventionoritsapplicationoruses.Whilethisinventionisdescribedinconnectionwithelectricvehicles,thoseskilledintheartwouldreadilyrecognizethatthebatterymonitorcanbeincorporatedtomonitorbatteriesusedwithothersystems.ReferringtoFIG.1,aschematicblockdiagramofabatterymonitorIOaccordingtooneembodimentofthepresentinventionisshown.Thebatterymonitor10isintended(omonitorthebatterjftemperatureandvoltageofaseriesofbatteries12positionedwithinabatterytub14.Inoneexample,thebatterytub14isoneofthreebatterytubseachholdingtenbatteries12asiscurrentlybeingusedintheTEVminivanavailablefromChryslerCorporation.Inthisexample,therewouldbethreebatterymonitorseachmonitoringthebatteriesinoneofthebatterytubs.Thebatterymonitor10isseparatedintoanisolatedside16andanonisolatedside18atanisolationborder20.Theisolatedside16iselectricallyisolatedfromthenon-isolatedside18toeliminateallofthecommonvoltagesourcesandgroundsbetweenthesides16and18(i.e.,galvanicallyisolated).Inthismanner,thebatterymonitor10canbepositionedproximatetothebatterytub14orbemountedtothebatterytub14soastoreducehighpowerregionsoftheelectricvehicleforsafetyandelectromagneticcompatibility(EMC)purposes.Thebatterymonitor10monitorsbatterytemperatureandvoltageforthebatteries12heldinthebatterytub14,Thebatteries12areconnectedinseriesandeachindividualbattery12hasavoltagerangeofbetweenabout0to20volts.Aseriesofhighpowerinputlines22areconnectedtothebatteries12toprovideasignalof(hevoltageacrosseachbattery12.Inthisembodiment,apairofhighpowerinputlines22isconnectedacrosseachbatterj,12suchthata3singleline22iselectricallyconnectedbetweeneachbattery12.Inthismanner,aline22isconnectedtoapositiveterminalofonebattery12andanegativeterminalofanadjacentbattery12.Therefore,oneline22isprovidedtodetermineapositivesignalofonebattery12andanegativesignalofanadjacentbattery12.Inthisconfiguration,eleveninputlines22arenecessarytodeterminethevoltageacrosseachofthetenbatteries12.Inapreferredembodiment,thebatterymonitor10ismountedonorincloseproximitytothebatterytub14ioreduce(helengthofthehighpowerinputlines22whichareconnectedtothebatteries12.Thevoltagesfromthebatteries12ontheinputlines22areappliedtoanattenuator24.Inoneembodiment,theattenuator24hasan8:1ratiosoastoattenuatethevoltagestoavoltagerangeofbetweenabout0to2.5volts.Theattenuator24includesaprecisionresistordividernetwork,wellknowntothoseskilledintheart,fabricatedonasinglesubstrate(notshown).Thisconstructionallowstheattenuator24tobeaccuratesincealltheresistorsinthenetworkwillvaryevenlywithanytemperaturechanges.Theelevenoutputlinesfromtheattenuator24includeten(10)positive(+)batteryterminallines26andten(10)negative(-)batteryterminallines28forallofthebatteries12,asdiscussedabove.Thelines26and28areappliedtoafifteenchanneldifferentialmodeanalogmultiplexer30.Tenofthechannelsoftheanalogmultiplexer30areforthebatteryvoltageoutputsfromtheattenuator24.Therefore,toreachbattery12thereisapositiveandnegativevoltagelinefromtheattenuator24.Inoneembodiment,themultiplexer30includesmultipleADG509AKNanalogmultiplexerchipseachhavingfour(4)inputchannels.Acontrolsignal(discussedbelow)appliedtothemultiplexer30causes(hemultiplexer30toselectapairofinputsfromthelines26and28representingavoltageacrossoneofthebatteries12.Theselectedvoltageisappliedtoadifferentialamplifier32tobebufferedandamplified.Theoutputlinesfromtheattenuator24arealsoappliedtoaseriesoften(10)switchedfillers34,oneofwhichisshownhere.Eachswitchedfilter34receivesapairofvoltageoutputlinesfrom(heattenuator24thatrepresentsthevoltageacrossoneofthebatteries12.Eachswitchedfiller34consistsofaswitch36andacapacitor38.Theswitch36canbeanADG201AKNswitchand(hecapacitor38canbea10/ifcapacitor.Acontrolsignal(discussedbelow)causestheswitchedfilters34tobeselectivelyswitchedintothebatterymonitor10bytheswitches36simultaneouslytofilteroutbatterylinenoiseandalsoioallowthecapacitors38topre-charge.Duringnormaloperationoftheelectricvehicle,thefilters34aregenerallyswitchedintothebatterjfmonitor10whichcausesaslowerresponsetimeasaresultofthecapacitors38beingcharged.Ibobtainaninstantaneousvoltagemeasurementacrossthebatteries12,thefilters34areswitchedoutofthemonitor10.Thefilters34aregenerallyswitchedoutofthemonitor10momentarilywhentheelectricvehicleis;notoperatingandthebatteries12areinachargingroutinesincethereislessbatterylinenoiseduringthiscondition(i.e.nocurrentowingfrombatteries12topowerelectricmotor).Duringthechargingroutineoftheelectricvehicle,thebatteries12aremomentarilyremovedfromachargingcircuit(notshown)whichdropsthecurrenttozero.Thefillers34arethenremovedorswitchedoutof(hebatterymonitor10andaninstantaneousbatteryvoltagemeasurementismade.Thereafter,thechargingcircuitisagainconnectedtothebatteries12andthefilters34areswitchedinto(heba(terj,monitor10.Itshouldalsobenotedthat(hefilters34canbeswitchedoutofthemonitor10duringnormaloperationoftheelectricvehicletoobtainaninstantaneousvoltagereading.4Inadditiontomonitoringbaeryvoltages,thebauerymonitor10monitorsbatterytemperatureusingfive(5)temperaturemonitors40oneofwhichisshownhere.Thetemperaturemonitors40monitorbatterytemperaturesforeveryotherbatterjr12inthebatterytub14sincetemperaturesforadjacentbatteries12aregenerallysimilar.Thetemperaturemonitors40consistofavoltagereference(Vref)andaresistor42inserieswithafiltercapacitor44.Atemperaturecommonsignalfromaknowntemperaturesource(notshown)isappliedtotheanodeofthecapacitor44.Athermistor46connectedinparallelwiththefiltercapacitor44ismountedproximatetothebattery12beingmonitored.Thevoltagereferenceisabout2.5voltsandcanbeprovidedbyastablevoltagereferenceICsuchasanAD580JT.Thefiltercapacitor44ispreferablyabankofcapacitorssucha10/Ftantalumcapacitorinparallelwitha0.1ZiFceramiccapacitorioachieveawidefilterbandwidth.Thethermistor46ispreferablyaUnicurvethermistor.Thevoltagedropacrossthefive(5)thermistors46areappliedtothemultiplexer30alongwiththefive(5)temperaturecommonsignals.Thecontrolsignalappliedtothemultiplexer30alsoselectsthetemperaturesignalsfromthetemperaturemonitors40.Whenthebatterymonitor10ismeasuringthebatterjfvoltage,thedifferentialamplifier32determinesthevoltagedifferencebetweenapairofvoltagechannelsthatareselectedbythemultiplexer30.Aserialanalogsignalfromtheamplifier32isappliedtoananalog-to-digital(A/D)converter48whichconvertstheanalogsignaltoadigitalserialsignal.TheA/Dconverter48couldbeanynumberofconventionalanalogtodigitalconvertersknownintheart.Theserialdigitaldataisthentransferredfromtheisolatedside16acrosstheborder20byanopto-isolator50.Theopto-isolator50isacombinationofaphotodiodeandaphototransistorwhereanopticalsignalfromthephotodioderepresentingthehighpowerdigitalsignalistransmittedacrosstheborder20tobereceivedbythephototransistoronthelowvoltagenon-isolatedside18oftheborder20.Inoneembodiment,theopto-isolator50isahighspeedHewletPackard(HP)6N137opto-isolators.However,oneskilledintheartwouldreadilyrecognizethatotheropto-isolatorscouldbeused,aswellasvariousothertypeofisolatorssuchastransformers.Thedigitalserialdataprovided(othenon-isolatedside18throughtheopto-isolator50isappliedtoamicroprocessor52throughaninverterbuffer54.Themicroprocessor52canbeaMotorola68HC05X4processorhavingan“onboard,MCAN(MotorolaControllerAreaNetwork)differentialcommunicationbus56.Thecommunicationbus56isatwistedpaircommunicationbuswhichcommunicateswithothermodulesthroughouttheelectricvehicle.Itshouldbenoted(hatvariousothercommunicationbussescouldalsobeutilizedsuchasCCD,J185()orETHERNET.Thebatterymonitor1()iscontrolledbyaddressinputs58tothemicroprocessor52.Theinputs58areexternallyjumperedinthevehiclewireharnesssuchthatmultiplebatterymonitorsIOeachmonitoringabatterytub14intheelectricvehiclecanbeindependentlycommunicat