预览加载中，请您耐心等待几秒...

基于Buck-Boost电路的DCDC变换器的设计.docx

预览
1/2
2/2

在线预览结束，喜欢就下载吧，查找使用更方便

下载提示 文本预览

如果您无法下载资料，请参考说明：

1、部分资料下载需要金币，请确保您的账户上有足够的金币

2、已购买过的文档，再次下载不重复扣费

3、资料包下载后请先用软件解压，在使用对应软件打开

基于Buck-Boost电路的DCDC变换器的设计 Introduction: Inmodernelectronicsystems,DC-DCconvertersplayacrucialroleinpowermanagementbyconvertingoneDCvoltageleveltoanother.Buck-Boostconverter,alsoknownasstep-up/step-downconverter,isoneofthemostwidelyusedtopologiesinDC-DCswitchingpowersupplies.ThispaperdiscussesthedesignofaBuck-Boostconverter,itsoperatingprinciple,controlsystem,andimplementation. Buck-BoostConverterOperatingPrinciple: TheBuck-Boostconverterhastwomodesofoperation:step-downandstep-up.Inthestep-downmode,theinputvoltageisgreaterthantheoutputvoltageandinthestep-upmode,theinputvoltageislowerthantheoutputvoltage.TheBuck-Boostconverterconsistsoffourmajorcomponents:aninputDCsource,aswitchingdevice,aninductor,andanoutputcapacitor.Theswitchingdeviceturnsonandoff,maintainingtheinductorcurrent.Whentheswitchison,theinductorcurrentincreases,andwhentheswitchisoff,theinductorcurrentdecreases.Theconverter'soutputvoltageisdeterminedbytheinductor'stimeconstant,theinputvoltage,andthedutycycleoftheswitch. ControlSystem: ThecontrolsysteminaBuck-Boostconverterisdividedintotwostages:voltagefeedbackandcurrentfeedback.Voltagefeedbackcontrolstheoutputvoltagebycomparingtheoutputvoltagetoareferencevoltage,andtheerrorvoltageisfedtoapulse-widthmodulation(PWM)controller.ThePWMcontrolleradjuststhepulsewidthoftheswitchtomaintaintheoutputvoltageatthedesiredlevel.Currentfeedbackcontrolstheswitchcurrentandprotectstheinductorfromover-currentdamage.Whentheswitchcurrentexceedsthesetlimit,thePWMcontrollerreducesthepulsewidthtocontrolthecurrent. Design: ThedesignprocessofaBuck-Boostconverterstartswithdeterminingtheinputandoutputvoltagelevelsandtheoutputcurrent.Theconverter'sefficiency,powerdissipation,andotherparametersarealsospecified.Then,theinductorandcapacitorvaluesarecalculatedusingthedesiredripplecurrentandvoltage,respectively.Theswitchingfrequencyisselectedbasedontheconverter'sapplicationandthetrade-offbetweenswitchinglossesandefficiency.Thedutycycleoftheswitchiscalculatedusingthetransformervoltagetransf