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1、畢業(yè)論文(設(shè)計(jì))學(xué)生姓名:學(xué)號(hào):所在學(xué)院:自動(dòng)化與電氣工程學(xué)院專業(yè):自動(dòng)化設(shè)計(jì)(論文)題目:光伏逆變器的并網(wǎng)控制仿真指導(dǎo)教師:2011年6月10日摘要世界環(huán)境的日益惡化和傳統(tǒng)能源的日益枯竭,促使了對(duì)新能源的開發(fā)和發(fā)展。具有可持續(xù)發(fā)展的太陽能資源受到了各國的重視,各國相繼出臺(tái)的新能源法對(duì)太陽能發(fā)展起到了推波助瀾的作用。其中,光伏并網(wǎng)發(fā)電具有深遠(yuǎn)的理論價(jià)值和現(xiàn)實(shí)意義,僅在過去五年,光伏并網(wǎng)電站安裝總量已達(dá)到數(shù)千兆瓦。而連接光伏陣列和電網(wǎng)的光伏并網(wǎng)逆變器便是整個(gè)光伏并網(wǎng)發(fā)電系統(tǒng)的關(guān)鍵。光伏并網(wǎng)逆變器是將太陽能電池所輸出的直流電轉(zhuǎn)換成符合公共電網(wǎng)要求的交流電并送入電網(wǎng)的設(shè)備。首先介紹了光伏并網(wǎng)逆變
2、器。其次,本文采用直流電壓外環(huán)、電流內(nèi)環(huán)的雙閉環(huán)控制方法,既保證了逆變器輸出的靜態(tài)誤差為零,又保證了逆變器良好的輸出波形。隨后,本文詳細(xì)討論了并網(wǎng)過程中的軟件鎖相環(huán)技術(shù),對(duì)鎖相環(huán)電路的組成、工作原理進(jìn)行了研究。本文根據(jù)逆變器結(jié)構(gòu)的特點(diǎn),提出了基于DC-AC單級(jí)并網(wǎng)逆變器的結(jié)構(gòu)。在DC-AC轉(zhuǎn)換器中,采用輸出電流控制,根據(jù)正弦脈沖寬度調(diào)制的缺點(diǎn),提出空間矢量脈寬度調(diào)制方法對(duì)逆變器進(jìn)行控制,從而提高直流側(cè)電壓的利用率,減少諧波?;赟VPWM的控制原理,在MATLAB_simulink上建立系統(tǒng)模型,并進(jìn)行了仿真實(shí)驗(yàn)。仿真結(jié)果表明輸出電流與電網(wǎng)電壓保持同相位,從而證明了原理的可行性。關(guān)鍵詞:光
3、伏發(fā)電并網(wǎng)逆變器SVPWM鎖相環(huán)技術(shù)ABSTRACTTheworld'senvironmentisdeterioratingandtheincreasingdepletionoftraditionalenergysourcestopromotethedevelopmentofnewenergydevelopment.Solarenergyresourcesbythecountriesattachimportancetosustainabledevelopment,countrieshaveintroducedanewenergylawhasplayedaroleinfuelingthede
4、velopmentofsolarenergy.Amongthem,photovoltaicpowergenerationhasfar-reachingtheoreticalvalueandpracticalsignificance,inthepastfiveyearsalone,thetotalphotovoltaicpowerplantinstallationhasreachedthousandsofmegawatts.Connectedphotovoltaicarraysandgridphotovoltaicgrod-connectedinverteristhekeytotheenti
5、regrid-connectedPVsystems.PVgrid-connectedinvertersolarcelloutputDCintoACmeettherequirementsofthepublicgridandintothepowergridequipment.FirstintroducedthePVgrid-connectedinverter.Secondly,theDCvoltageloopandinnercurrentclosed-loopcontrolmethod,bothtoensurezerostaticerroroftheinverteroutput,butalso
6、toensurethattheinverteroutputwaveform.Subsequently,thedetaileddiscussionofthesoftwarephase-lockedlooptechnologyandnetworkprocess,thecompositionofthephase-lockedloopcircuit,theworkingprincipleofthestudy.Accordingtothecharacteristicsoftheinverterstructure,basedonthestructureoftheDC-ACsingle-stagegri
7、d-connectedinverter.DC-ACconverter,theoutputcurrentcontrol,accordingtotheshortcomingofthesinusoidalpulsewidthmodulation,spacevectorpulsewidthmodulationinvertercontrol,therebyimprovingtheutilizationoftheDCvoltagea