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2009届电气工程与自动化专业毕业设计外文翻译1TRANSLATEDFROMXIONGFUSHENG,DCSWITCHINGPOWERSUPPLYPROTECTIONTECHNOLOGY,GUANGZHOUTHEWORLDOFPOWERSUPPLYP,20022DCSWITCHINGPOWERSUPPLYPROTECTIONTECHNOLOGYABSTRACTTHEDCSWITCHINGPOWERSUPPLYPROTECTIONSYSTEM,PROTECTIONSYSTEMDESIGNPRINCIPLESANDMACHINEPROTECTIONMEASURES,ANANALYSISOFSWITCHINGPOWERSUPPLYINTHERANGEOFPROTECTEDCHARACTERISTICSANDITSDESIGNMETHODOLOGY,INTRODUCEDANUMBEROFPRACTICALPROTECTIONCIRCUITKEYWORDSSWITCHINGPOWERSUPPLYPROTECTIONCIRCUITSYSTEMDESIGN1、INTRODUCTIONDCSWITCHINGREGULATORUSEDINTHEPRICEOFMOREEXPENSIVEHIGHPOWERSWITCHINGDEVICES,THECONTROLCIRCUITISALSOMORECOMPLEX,INADDITION,THELOADSWITCHINGREGULATORSAREGENERALLYUSEDALARGENUMBEROFHIGHLYINTEGRATEDELECTRONICSYSTEMSINSTALLEDDEVICESTRANSISTORSANDINTEGRATEDDEVICETOLERANCEELECTRICITY,LESSHEATSHOCKSSWITCHINGREGULATORSTHEREFORESHOULDTAKEINTOACCOUNTTHEPROTECTIONOFVOLTAGEREGULATORSANDLOADTHEIROWNSAFETYMANYDIFFERENTTYPESOFCIRCUITPROTECTION,POLARITYPROTECTION,INTRODUCEDHERE,THEPROGRAMPROTECTION,OVERCURRENTPROTECTION,OVERVOLTAGEPROTECTION,UNDERVOLTAGEPROTECTIONANDOVERTEMPERATUREPROTECTIONCIRCUITUSUALLYCHOSENTOBESOMECOMBINATIONOFPROTECTION,CONSTITUTESACOMPLETEPROTECTIONSYSTEM2、POLARITYPROTECTIONDCSWITCHINGREGULATORINPUTAREGENERALLYNOTREGULATEDDCPOWERSUPPLYOPERATINGERRORSORACCIDENTSASARESULTOFTHESITUATIONWILLTAKEITSWRONGPOLARITY,SWITCHINGPOWERSUPPLYWILLBEDAMAGEDPOLARITYPROTECTIONPURPOSES,ISTOMAKETHESWITCHINGREGULATORONLYWHENTHECORRECTPOLARITYISNOTCONNECTEDTODCPOWERSUPPLYREGULATORTOWORKATCONNECTINGASINGLEDEVICECANACHIEVEPOWERPOLARITYPROTECTIONSINCETHEDIODEDTOFLOWTHROUGHSWITCHINGREGULATORINPUTTOTALCURRENT,THISCIRCUITAPPLIEDINALOWPOWERSWITCHINGREGULATORMORESUITABLEPOWERINTHELARGEROCCASION,WHILETHEPOLARITYPROTECTIONCIRCUITASAPROCEDURETOPROTECTALINK,SAVETHEPOWERREQUIREDFORPOLARITYPROTECTIONDIODES,POWERCONSUMPTIONWILLBEREDUCEDINORDERTOEASYTOOPERATE,MAKEITEASIERTOIDENTIFYTHECORRECTPOLARITYORNOT,COLLECTTHENEXTLIGHT仇有年宽输入电压高频开关电源的设计23、PROCEDURESTOPROTECTSWITCHINGPOWERSUPPLYCIRCUITISRATHERCOMPLICATED,BASICALLYCANBEDIVIDEDINTOLOWPOWERANDHIGHPOWERPARTOFTHECONTROLPARTOFTHESWITCHSWITCHISAHIGHPOWERTRANSISTORS,FORTHEPROTECTIONOFTHETRANSISTORSWITCHISTURNEDONOROFFPOWERSAFETY,WEMUSTFIRSTMODULATOR,AMPLIFIERANDOTHERLOWPOWERCONTROLCIRCUITTOTHISEND,THEBOOTTOENSURETHECORRECTPROCEDURESSWITCHINGREGULATORSGENERALLYTAKETHEINPUTOFASMALLINDUCTOR,THEINPUTFILTERCAPACITORMOMENTINTHEBOOT,FILTERCAPACITORWILLFLOWALOTOFSURGECURRENT,THESURGECURRENTCANBESEVERALTIMESMORETHANTHENORMALINPUTCURRENTSUCHALARGESURGECURRENTMAYCONTACTTHEGENERALPOWERSWITCHORRELAYCONTACTMELTING,ANDTHEINPUTFUSEFUSEINADDITION,THECAPACITORSURGECURRENTWILLDAMAGETOSHORTENTHELIFESPANOFPREMATUREDAMAGETOTHISEND,THEBOOTSHOULDBEACCESSTOACURRENTLIMITINGRESISTOR,THROUGHTHECURRENTLIMITINGRESISTORTOCAPACITORCHARGINGINORDERNOTTOMAKETHECURRENTLIMITINGRESISTOREXCESSIVEPOWERCONSUMPTION,THUSAFFECTINGTHENORMALSWITCHINGREGULATOR,ANDTHETRANSIENTPROCESSINTHEBOOTAFTERASHORTPERIODTHENAUTOMATICALLYRELAYSITTODCPOWERSUPPLYDIRECTLYTOTHESWITCHINGREGULATORPOWERSUPPLYTHISCIRCUITSWITCHINGREGULATORCALLEDASOFTSTARTCIRCUITSWITCHINGREGULATORCONTROLCIRCUITOFTHELOGICCOMPONENTSREQUIREDOROPAMPAUXILIARYPOWERSUPPLYTOTHISEND,THEAUXILIARYPOWERSUPPLYMUSTBEINTHESWITCHCIRCUITTHISCONTROLCIRCUITCANBEUSEDTOENSURETHEBOOTNORMALBOOTPROCESSISTOIDENTIFYTHEPOLARITYOFINPUTPOWER,VOLTAGEPROTECTIONPROCEDURES→BOOT→AUXILIARYPOWERSUPPLYCIRCUITANDTHROUGHCURRENTLIMITINGRESISTORROFTHESWITCHINGREGULATORINPUTCAPACITORC→CHARGEMODULATIONSWITCHINGREGULATORCIRCUIT,→SHORTCIRCUITCURRENTLIMITINGRESISTORSTABILITYSWITCHINGREGULATORINTHESWITCHINGREGULATOR,THEMACHINESJUSTBECAUSETHEOUTPUTCAPACITANCE,ANDCHARGETOTHERATEDOUTPUTVOLTAGEVALUEOFTHENEEDFORACERTAINPERIODOFTIMEDURINGTHISTIME,SAMPLINGTHEOUTPUTAMPLIFIERWITHLOWINPUTVOLTAGESAMPLING,CLOSEDLOOPREGULATIONCHARACTERISTICSOFTHESYSTEMWILLFORCETHESWITCHINGOFTHETRANSISTORCONDUCTIONTIMELENGTHENED,SOTHATSWITCHINGTRANSISTORDURINGTHISPERIODWILLTENDTOCONTINUOUSCONDUCTION,ANDEASILYDAMAGEDTOTHISEND,THEREQUIREMENTSOFTHISPARAGRAPHINTHEBOOTTIME,THESWITCHTOSWITCHTHEOUTPUTMODULATIONCIRCUITTRANSISTORBASEDRIVESIGNALOFTHEPULSEWIDTHMODULATION,CANGUARANTEETHESWITCHINGTRANSISTORBYTHECUTOFFSWITCHESAREBECOMING2009届电气工程与自动化专业毕业设计外文翻译3MOREANDMORENORMALSTATE,THEREFORETHEPROTECTIONOFTHESETTINGUPOFABOOTTOTIEINWITHTHESOFTSTART4、OVERCURRENTPROTECTIONWHENTHELOADSHORTCIRCUIT,OVERLOADCONTROLCIRCUITFAILUREORUNFORESEENCIRCUMSTANCES,SUCHASWOULDCAUSETHEFLOWOFSWITCHINGVOLTAGEREGULATORTRANSISTORCURRENTISTOOLARGE,SOTHATINCREASEDPOWERTUBES,FEVER,IFTHEREISNOOVERCURRENTPROTECTIONDEVICE,HIGHPOWERSWITCHINGTRANSISTORMAYBEDAMAGEDTHEREFORE,THESWITCHINGREGULATORINTHEOVERCURRENTPROTECTIONISCOMMONLYUSEDTHEMOSTECONOMICALWAYISTOUSESIMPLEFUSEASARESULTOFTHEHEATCAPACITYOFSMALLTRANSISTORS,GENERALFUSEPROTECTIONINGENERALCANNOTPLAYAROLEINTHERAPIDFUSECOMMONFUSETHISMETHODHASTHEADVANTAGEOFTHEPROTECTIONOFVULNERABLE,BUTITNEEDSTOSWITCHTRANSISTORINACCORDANCEWITHSPECIFICSECURITYREQUIREMENTSOFTHEWORKAREATOSELECTTHEFUSESPECIFICATIONSTHISDISADVANTAGEISOVERCURRENTPROTECTIONMEASURESBROUGHTABOUTBYTHEINCONVENIENCEOFFREQUENTREPLACEMENTOFFUSESLINEARVOLTAGEREGULATORCOMMONLYUSEDINTHEPROTECTIONANDCURRENTLIMITINGTOPROTECTTHECUTOFFINTHESWITCHINGREGULATORCANBEAPPLIEDHOWEVER,ACCORDINGTOTHECHARACTERISTICSOFSWITCHINGREGULATORS,THEPROTECTIONCIRCUITCANNOTDIRECTLYCONTROLTHEOUTPUTTRANSISTORSWITCHES,ANDOVERCURRENTPROTECTIONMUSTBECONVERTEDTOPULSEOUTPUTCOMMANDSTOCONTROLTHEMODULATORTOPROTECTTHETRANSISTORSWITCHINORDERTOACHIEVEOVERCURRENTPROTECTIONAREGENERALLYREQUIREDSAMPLINGRESISTORINSERIESINTHECIRCUIT,THISWILLAFFECTTHEEFFICIENCYOFPOWERSUPPLY,SOMOREFORLOWPOWERSWITCHINGREGULATOROFOCCASIONSINTHEHIGHPOWERSWITCHINGPOWERSUPPLY,BYTAKINGINTOACCOUNTTHEPOWERCONSUMPTIONSHOULDBEAVOIDEDASFARASPOSSIBLEACCESSTOTHESAMPLINGRESISTORTHEREFORE,THEREWILLUSUALLYBECONVERTEDTOOVERCURRENTPROTECTION,ANDUNDERVOLTAGEPROTECTION5、OVERVOLTAGEPROTECTIONSWITCHINGREGULATORSINPUTOVERVOLTAGEPROTECTION,INCLUDINGOVERVOLTAGEPROTECTIONANDOUTPUTOVERVOLTAGEPROTECTIONSWITCHINGREGULATORISNOTUSEDINDCPOWERSUPPLYVOLTAGEREGULATORANDRECTIFIER,SUCHASBATTERYVOLTAGE,IFTOOHIGH,SOSWITCHINGREGULATORISNOTWORKINGPROPERLY,OREVENDAMAGETOINTERNALDEVICES,THEREFORE,ITISNECESSARYTOUSETHEINPUTOVERVOLTAGEPROTECTIONCIRCUITUSINGTRANSISTORSANDRELAYSPROTECTIONCIRCUITINTHECIRCUIT,WHENTHEINPUTDCPOWERSUPPLYVOLTAGEHIGHERTHANTHEVOLTAGEREGULATORDIODEBREAKDOWNVOLTAGEVALUE,THEBREAKDOWNVOLTAGEREGULATORTUBE,ACURRENT仇有年宽输入电压高频开关电源的设计4FLOWINGTHROUGHRESISTORR,SOTHATVTURNONTRANSISTOR,RELAY,NORMALLYCLOSEDCONTACTOFFOPEN,CUTOFFTHEINPUTVOLTAGEREGULATORVOLTAGEREGULATORWHICHCONTROLSTHEVALUEOFVZESRMAXUBETHEPOLARITYOFINPUTPOWERWITHTHEINPUTPROTECTIONCIRCUITCANBECOMBINEDWITHOVERVOLTAGEPROTECTION,POLARITYPROTECTIONCONSTITUTEADIFFERENTIALCIRCUITANDOVERVOLTAGEPROTECTIONOUTPUTOVERVOLTAGEPROTECTIONSWITCHINGPOWERSUPPLYISESSENTIALINPARTICULAR,FORTHE5VOUTPUTOFTHESWITCHINGREGULATOR,ITISALOTOFLOADONAHIGHLEVELOFINTEGRATIONOFTHELOGICDEVICEIFATWORK,SWITCHINGREGULATORSUDDENDAMAGETOTHESWITCHTRANSISTOR,THEOUTPUTPOTENTIALMAYBEINCREASEDIMMEDIATELYTOTHEIMPORTATIONOFNONREGULATEDDCPOWERSUPPLYVOLTAGEVALUE,CAUSINGGREATLOSSINSTANTANEOUSCOMMONLYUSEDMETHODISSHORTCIRCUITPROTECTIONTHYRISTORTHESIMPLESTOVERVOLTAGEPROTECTIONCIRCUITWHENTHEOUTPUTVOLTAGEISTOOHIGH,THEREGULATORTUBEBREAKDOWNTRIGGEREDTHYRISTORTURNON,THEOUTPUTSHORTCIRCUIT,RESULTINGINOVERCURRENTTHROUGHTHEFUSEORCIRCUITPROTECTIVEDEVICETOCUTOFFTHEINPUTTOPROTECTTHELOADTHISCIRCUITISEQUIVALENTTOTHERESPONSETIMEOFTHEOPENINGTIMEOFTHYRISTORISABOUT510ΜSTHEDISADVANTAGEISTHATITSACTIONISFIXEDVOLTAGE,TEMPERATURECOEFFICIENT,ANDACTIONPOINTSOFINSTABILITYINADDITION,THEREISAVOLTAGEREGULATORCONTROLPARAMETERSOFTHEDISCRETE,MODELOVERVOLTAGESTARTUPTHESAMEBUTHASDIFFERENTVALUES,DIFFICULTTODEBUGESCASUDDENINCREASEINOUTPUTVOLTAGE,TRANSISTORSV1,V2CONDUCTION,THETHYRISTORCONDUCTIONREFERENCEVOLTAGEVZBYTYPE6、UNDERVOLTAGEPROTECTIONOUTPUTVOLTAGEBELOWTHEVALUETOREFLECTTHEINPUTDCPOWERSUPPLY,SWITCHINGREGULATOROUTPUTLOADINTERNALORUNUSUALOCCURRENCEINPUTDCPOWERSUPPLYVOLTAGEDROPSBELOWTHESPECIFIEDVALUEWOULDRESULTINSWITCHINGREGULATOROUTPUTVOLTAGEDROPS,THEINPUTCURRENTINCREASES,NOTONLYENDANGERTHESWITCHINGTRANSISTOR,BUTALSOENDANGERTHEINPUTPOWERTHEREFORE,INORDERTOSETUPDUETOVOLTAGEPROTECTIONDUETOSIMPLEVOLTAGEPROTECTIONWHENNOVOLTAGEREGULATORINPUTNORMAL,ZDBREAKDOWNVOLTAGEREGULATORTUBE,TRANSISTORSVCONDUCTION,THERELAYACTION,CONTACTPULLIN,POWERSWITCHINGREGULATORWHENTHEINPUTBELOWTHEMINIMUMALLOWABLEVOLTAGEVALUE,THEREGULATORTUBEZDBARRIER,VCUTOFF,CONTACTKAIHOP,SWITCHINGREGULATORCANNOTWORKINTERNALSWITCHINGREGULATOR,ASTHECONTROLSWITCHTRANSISTORCIRCUITDISORDERSORFAILUREWILLDECREASETHEOUTPUTVOLTAGE；LOADSHORTCIRCUITOUTPUTVOLTAGEWILLALSODECLINE
