文档名：基于能量模型的临界导通模式Boost变换器软开关方法
摘要：在变换器高频化发展的趋势中,功率器件的软开关实现对变换效率的影响更加突出.无辅助电路的临界导通工作模式下,Boost变换器主开关管在特定增益下无法实现软开关.为此,该文提出一种能量模型及相应的软开关实现方法.首先,建立死区前后储能元件能量变化的数学模型.然后,结合死区起止时刻的能量平衡方程,研究软开关无法实现的电路机理.在此基础上,考虑开关管输出电容非线性特征,提出软开关实现方法,避免了复杂谐振过程的时域精确建模,提高软开关实现的准确性.最后,搭建500W实验样机进行实验,结果表明,相较于对谐振过程建模的传统时域模型,所提方法将实际开通电压降低47%,使峰值变换效率提升0.4%,进而验证了其有效性.
Abstract：SoftswitchingiscrucialforBoostconverters,especiallyinthetrendofhigh-frequencydevelopment.Duringboundaryconductionmode(BCM),zerovoltageswitching(ZVS)ofthemainswitchoftheBoostconverterisachievedwithoutauxiliarycircuits,whichisfavoredinsmallandmediumpowerapplications.However,whenthegainoftheconverterisgreaterthan2,ZVSbasedonBCMcannotberealizedbecauseofthepositiveresonancevalleyofitsdrain-sourcevoltagevdsinthedeadzone.Therefore,amethodextendingthesynchronizedswitchtimeisproposedbasedontime-domaindeadzoneanalysis.Anegativecurrentisobtainedontheinductoratthestartofthedeadzone,forcingtheresonancevalleyofvdstogetcloserto0.Duetothecalculationoftheresonanceprocess,thecomplexityofthecalculationprocessandresultexpressionisgreatlyincreased.However,inpractice,therealizationofsoftswitchingonlyfocusesonthestartandendmomentofthedeadzone.Complexanalysisoftheresonanceprocessisoptional.Besides,nonlinearcharacteristicsoftheoutputcapacitorCossonpowerswitchesareignoredinthetime-domainmodel,causinginaccurateinductorcurrentatthestartofthedeadzoneandisharmfultoreducingswitchlosses.Thus,thispaperproposesaZVSmethodbasedontheenergymodel.Firstly,theenergymodelofpassivepowercomponentsisestablishedduringthedeadzone.Insteadofconsideringtheentiredeadzone,onlyenergychangeatthestartandendofthedeadzoneisfocused.Secondly,conditionswithpowervariationsareanalyzed,andtherequirementforZVSrealizationisgivenfromtheenergybalanceperspective.Then,consideringthenonlinearcharacteristicsofCoss,anaccurateexpressionofthenegativeinductancecurrentneededisobtained.TheZVSrealizationmethodbasedonthepowermodelavoidscomplexresonantprocessesoftime-domainmodeling.Accordingly,lesscalculationisneeded,andtheaccuracyofsoftswitchingimplementationisimproved.Finally,a500Wexperimentalprototypeisbuilttoverifytheproposedmethod.Experimentsareconductedwhentheinputvoltageis200Vand250V,respectively,andtheoutputvoltageis300V.Withaninputvoltageof200V,theproposedmethodreducestheactualswitchingvoltageby86%comparedwiththecriticalconductionmodeand60%withthetime-domainmodel.Under250V,theproposedmethodreducestheactualturn-onvoltageby70%and47%comparedwiththecriticalconductionmodeandthetime-domainmodel,respectively.Sincetheswitchingcurrentbetweendifferentmethodsisalmostthesame,switchinglossisproportionaltotheswitchingvoltage.Therefore,theproposedmethodcaneffectivelydecreaseswitchingloss.Conclusionsbelowcanbedrawnfromexperimentalresults.(1)Theproposedmethodisbasedonenergybalancingthestartandendofthedeadzone,simplifyingtheanalysisandcalculationprocessofsoftswitchingimplementation.(2)TheproposedmodelconsidersthedynamiccharacteristicsoftheoutputcapacitorCossaccurately,whichimprovestheaccuracyofthenegativeinductancecurrent.(3)Comparedwiththetraditionaltime-domainmodel,theproposedmodelandZVSimplementationmethodcaneffectivelyreducetheactualswitchinglossandimprovepeakefficiencyby0.4%,whichverifiestheZVSimplementationmethodbasedontheenergymodel.
作者：王议锋 杨绍琪 马小勇 陶珑 王忠杰Author：WangYifeng YangShaoqi MaXiaoyong TaoLong WangZhongjie
作者单位：天津大学电气与自动化工程学院天津300072
刊名：电工技术学报 ISTICEIPKU
Journal：TransactionsofChinaElectrotechnicalSociety
年，卷(期)：2024, 39(10)
分类号：TM46
关键词：Boost变换器 临界导通模式 能量模型 软开关 开关管输出电容
Keywords：Boostconverter boundaryconductionmode energymodel softswitching switchoutputcapa-citance
机标分类号：TM461TN402TM923.02
在线出版日期：2024年5月31日
基金项目：基于能量模型的临界导通模式Boost变换器软开关方法[
期刊论文] 电工技术学报--2024, 39(10)王议锋 杨绍琪 马小勇 陶珑 王忠杰在变换器高频化发展的趋势中,功率器件的软开关实现对变换效率的影响更加突出.无辅助电路的临界导通工作模式下,Boost变换器主开关管在特定增益下无法实现软开关.为此,该文提出一种能量模型及相应的软开关实现方法.首先...参考文献和引证文献
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基于能量模型的临界导通模式Boost变换器软开关方法 Soft Switching Method of Boundary Conduction Mode Boost Converter Based on Energy Model
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