基于Buck变换器的光伏发电系统MPPT控制

29220106计算技术与自动化ComputingTechnologyandAutomationVol29,No2Jun.2010:2010-01-12:(1985),,,,:(E-mail:[e-mail]);(1958),,,,::1003-6199(2010)02-0028-04BuckMPPT陈丽,王英健(,410014):介绍以Buck变换器为对象的太阳能光伏发电系统用Buck变换器实现对光伏发电系统的最大功率跟踪,采用逐次逼近法的MPPT控制策略,通过调节Buck变换器的PWM占空比输出,使得负载的等效阻抗跟随光伏电池的输出阻抗,使光伏阵列在任何条件下获得最大功率输出,跟踪最大功率仿真表明MPPT(最大功率跟踪)控制策略的可行性:光伏发电系统;Buck变换器;MPPT;逐次逼近法:TP27:ATheMPPTControlforPhotovoltaicGeneratingSystemBasedonaBuckConverterCHENLi,WANGYingjian(CollegeofElectricalandInformationEngineering,ChangshaUniversityofscienceandtechnology,Changsha410014,China)Abstract:ThepaperintroducesphotovoltaicgeneratingsystembasedonBuckconverter.themaximumpowertrackingcanbeachievedbyusingBuckconverter,theMPPTcontrolstrategyofsuccessiveapproximationmethodisadoptedinthepaper,EquivalentresistanceofloadwillchangewiththeoutputresistanceofphotovoltaicbatterybyadjustingPWMDutyRatiooutputofBuckconverter,whichmakesphotovoltaicarraygettingthemaximumpoweroutputonanycondition,trackingmaximumpower.TheexperimentalresultsconfirmfeasibilityofMPPTcontrolstrategyKeywords:photovoltaicgeneratingsystem;buckconverter;maximumpowerpointtracking;successiveapproximationmethod1,[1],,,,BuckPWM,,,;,21,DC/DC,DC/DC;,,;,292:BuckMPPT[2];,DC/DC,,,图1系统结构设计图3,,,,[3]2,:Ipv=Iph-IoexpqVpv+IpvRsnKT-1-Vpv+IpvRsRsh(1),Iph;Io;Vpv;q(1.610-19k);k(1.3810-23J/K);T(K);n图2光伏电池等效电路,Rsh,,4BuckBuck,,[4]3图3Buck变换器:UoUi=tonton+toff=tonT=(2)L,:Ii=Io(3)(2)(3):UoIo=Ui1Ii=2UiIi(4),Ro=2Ri(5)tonQ,toffQ,T,,(5),,,,,5MPPT4[5],,,,I;Isc;Im;V;Voc;Vm;Pm图4光伏电池的伏安特性曲线2920106MPPT,DC/DC,PWM,,MPPT,5,D,T,PtDtt,PWM,t-1t,PWMPtPt-1,tt-1Pmax,,;PtPt-1,t-1tPmax,,6MATLABSIMULINK,DC/DC,6TQVmVocImIsc25!C1kw/m230V40V10A15A7图5逐步逼近法图图6MPPT控制的系统仿真模型图7光伏阵列仿真模型30292:BuckMPPTMPPT8图8MPPT功率追踪图,PWM,,MPPT6,,BuckMPPT,PWM,,,[1].[D].:,2007[2].[M].:,2005[3].MPPT[J].,2009,25(7):1-6.[4],.[M].:,2000.[5]EDUARDOLOrtizRivera.MaximumPowerPointTrackingusingtheOptimalDutyRatioforDC-DCConvertersandLoadMatchinginPhotovoltaicApplications[J].IEEE.2008,20(7):67-73.31