光伏發(fā)電系統(tǒng)外文翻譯文獻

文獻信息：文獻標題：ANewControllerSchemeforPhotovoltaicsPowerGenerationSystems(光伏發(fā)電系統(tǒng)的一種新的控制方案)國外作者：TamerT.N.Khatib，AzahMohamed，NowshadAmin文獻出處：《EuropeanJournalofScientificResearch》，2009,Vol.33No.3,pp515-524字數(shù)統(tǒng)計：英文1337單詞,7006字符；中文2149漢字外文文獻：ANewControllerSchemeforPhotovoltaicsPower

GenerationSystemsAbstract:Thispaperpresentsanewcontrollerschemeforphotovoltaic(PV)powergenerationsystems.TheproposedPVcontrollerschemecontrolsboththeboostconverterandthebatterychargerbyusingamicrocontrollerinordertoextractmaximumpowerfromthePVarrayandcontrolthechargingprocessofthebattery.TheobjectiveofthepaperistopresentacosteffectiveboostconverterdesignandanimprovedmaximumpowerpointtrackingalgorithmforthePVsystem.AMATLABbasedsimulationmodeloftheproposedstandalonePVsystemhasbeendevelopedtoevaluatethefeasibilityofthesysteminensuringmaximumpowerpointoperation.1.IntroductionRecently,theinstallationofPVgenerationsystemsisrapidlygrowingduetoconcernsrelatedtoenvironment,globalwarming,energysecurity,technologyimprovementsanddecreasingcosts.PVgenerationsystemisconsideredasacleanandenvironmentally-friendlysourceofenergy.ThemainapplicationsofPVsystemsareineitherstandaloneorgridconnectedconfigurations.StandalonePVgenerationsystemsareattractiveasindispensableelectricitysourceforremoteareas.However,PVgenerationsystemshavetwomajorproblemswhicharerelatedtolowconversionefficiencyofabout9to12%especiallyinlowirradiationconditionsandtheamountofelectricpowergeneratedbyPVarraysvariescontinuouslywithweatherconditions.Therefore,manyresearchworksaredonetoincreasetheefficiencyoftheenergyproducedfromthePVarrays.ThesolarcellV-Icharacteristicsisnonlinearandvarieswithirradiationandtemperature.ButthereisauniquepointontheV-IandP-Vcurves,calledasthemaximumpowerpoint(MPP),atwhichatthispointthePVsystemissaidtooperatewithmaximumefficiencyandproducesitsmaximumpoweroutput.ThelocationoftheMPPisnotknownbutcanbetracedbyeitherthroughcalculationmodelsorsearchalgorithms.Thus,maximumpowerpointtracking(MPPT)techniquesareneededtomaintainthePVarray'soperatingpointatitsMPP.ManyMPPTtechniqueshavebeenproposedintheliteratureinwhichthetechniquesvaryinmanyaspects,includingsimplicity,convergencespeed,hardwareimplementationandrangeofeffectiveness.However,themostwidelyusedMPPTtechniqueistheperturbationandobservation(P&O)method.ThispaperpresentsasimpleMPPTalgorithmwhichcanbeeasilyimplementedandadoptedforlowcostPVapplications.TheobjectiveofthispaperistodesignanovelPVcontrollerschemewithimprovedMPPTmethod.TheproposedstandalonePVcontrollerimplementationtakesintoaccountmathematicalmodelofeachcomponentaswellasactualcomponentspecification.Thede-deorboostconverteristhefront-endcomponentconnectedbetweenthePVarrayandtheload.Theconventionalboostconvertermaycauseseriousreverserecoveryproblemandincreasetheratingofalldevices.Asaresult,theconversionefficiencyisdegradedandtheelectromagneticinterferenceproblembecomessevereunderthissituation.Toincreasetheconversionefficiency,manymodifiedstep-upconvertertopologieshavebeeninvestigatedbyseveralresearchers.Voltageclampedtechniqueshavebeenincorporatedintheconverterdesigntoovercometheseverereverse-recoveryproblemoftheoutputdiodes.Inthispaper,focusisalsogivenintheboostconverterdesign.AnotherimportantcomponentinthestandalonePVsystemsisthechargecontrollerwhichisusedtosavethebatteryfrompossibledamageduetoover-chargingandover-discharging.Studiesshowedthatthelifetimeofabatterycanbedegradedwithoutusingachargecontroller.TheproposednewcontrollerschemeforthestandalonePVsystemcontrolsboththeboostconverterandthechargecontrollerintwocontrolsteps.ThefirststepistocontroltheboostconvertersoastoextractthemaximumpowerpointofthePVmodules.Here,ahighstep-upconverterisconsideredforthepurposeofsteppingupthePVvoltageandconsequentlyreducingthenumberofseries-connectedPVmodulesandtomaintainaconstantdcbusvoltage.AmicrocontrollerisusedfordataacquisitionthatgetsPVmoduleoperatingcurrentandvoltageandisalsousedtoprogramtheMPPTalgorithm.Thecontrolleradoptsthepulsewidthmodulation(PWM)techniquetoincreasethedutycycleofthegeneratedpulsesasthePVvoltagedecreasessoastoobtainastableoutputvoltageandcurrentclosetothemaximumpowerpoint.Thesecondcontrolstepistocontrolthechargecontrollerforthepurposeofprotectingthebatteries.BycontrollingthechargingcurrentusingthePWMtechniqueandcontrollingthebatteryvoltageduringcharging,voltageshigherthanthegassingvoltagecanbeavoided.2.DesignoftheProposedPhotovoltaicSystemMostofthestandalonePVsystemsoperateinonemodeonlysuchthatthePVsystemchargesthebatterywhichinturnssupplypowertotheload.Inthismodeofoperation,thelifecycletimeofthebatterymaybereducedduetocontinuouscharginganddischargingofthebattery.TheproposedstandalonePVsystemasshownintermsofablockdiagraminFigure1isdesignedtooperateintwomodes:PVsystemsuppliespowerdirectlytoloadsandwhentheradiationgoesdownandtheproducedenergyisnotenough,thePVsystemwillchargethebatterywhichinturnssupplypowertotheload.Tomanagethesemodesofoperation,acontrollerisconnectedtotheboostconverterbyobservingthePVoutputpower.Figure1:ScheniiiticdiagramoftheproposedPVsystemClientsTlWLPWMvfVpvMicmcomtrylkr3?MethodologyForthepurposeofestimatingthemathematicalmodelsdevelopedfortheproposedstandalonePVsystem,simulationswerecarriedintermsoftheMATLABcodes.EachPVmoduleconsideredinthesimulationhasaratingof80Wattat1000W/m2,21.2Vopencircuitvoltage,5Ashortcircuitcurrent.ThePVmoduleisconnectedtoablockofbatterieswithofsizing60Ah,48V4.ResultsandDiscussionThesimulationresultsofthestandalonePVsystemusingasimpleMPPTalgorithmandanimprovedboostconverterdesignaredescribedinthissection.SimulationswerecarriedoutforthePVsystemoperatingabove30oCambienttemperatureandunderdifferentvaluesofirradiation.Figure9showsthePVarrayI-Vcharacteristiccurveatvariousirradiationvalues.Fromthefigure,itisobservedthatthePVcurrentincreaselinearlyastheirradiationvalueisincreased.However,thePVvoltageincreasesinlogarithmicpatternastheirradiationincreases.Figure10showsthePVarrayI-Vcharacteristiccurveatvarioustemperaturevalues.Itisnotedfromthefigurethat,thePVvoltagedecreasesastheambienttemperatureisincreased.

14).50Figure2:1-VcurvesatvariousradiationvaluesiS.5DD5ID1E2CVcltsge14).50Figure2:1-VcurvesatvariousradiationvaluesiS.5DD5ID1E2CVcltsge5554535255.43.2<+nuFigure3:1-VcurvesatdiffeienttemperatvievaluesQ10152025VoltageFigure4comparesthePVarrayP-VcharacteristicsobtainedfromusingtheproposedMPPTalgorithmandtheclassicalMPPTP&Oalgorithm.Fromthisfigure,itcanbeseenthatbyusingtheproposedMPPTalgorithm,theoperatingpointofPVarrayismuchclosertotheMPPcomparedtotheusingtheclassicalP&Oalgorithm.Figure4:ComparingP-Vcharacteristics<-ppMMPPbyclasicalmethod20Voltage<-ppMMPPbyclasicalmethod20VoltageT/MPPbyproposedmethodInaddition,theproposedboostconverterisabletogiveastableoutputvoltageasshowninFigure5.IntermsofPVarraycurrent,itcanbeseenfromFigure6thatthePVcurrentisclosertotheMPPcurrentwhenusingtheimprovedMPPTalgorithm.Thus,thetrackoperatingpointisimprovedbyusingtheproposedMPPTalgorithm.IntermsofefficiencyofthestandalonePVsystemwhichiscalculatedbydividingtheloadpowerwiththemaximumpowerofPVarray,itisnotedthattheefficiencyofthesystemisbetterwiththeproposedMPPTalgorithmascomparedtousingtheclassicalP&OalgorithmasshowninFigure7.Figure5:BoostconverteroutputvoltageFigure6:ComparingPVcurrentsFigure6:ComparingPVcurrentsGM血訕Figure7:ComparingefficiencyofPVsystem700900G—■—700900G—■—'WithproposedinethodVAthclassicinethod11005.ConclusionThispaperhaspresentedanefficientstandalonePVcontrollerbyincorporatinganimprovedboostconverterdesignandanewcontrollerschemewhichincorporatesbothasimpleMPPTalgorithmandabatterychargingalgorithm.ThesimulationresultsshowthatthePVcontrollerusingthesimpleMPPTalgorithmhasprovidedmorepowerandbetterefficiency(91%)thantheclassicalP&Oalgorithm.Inaddition,theproposedboostconverterdesigngivesabetterconverterefficiencyofabout93%.SuchaPVcontrollerdesigncanprovideefficientandstablepowersupplyforremotemobileapplications.中文譯文：光伏發(fā)電系統(tǒng)的一種新的控制方案摘要：本文提出了一種新的光伏（PV）發(fā)電系統(tǒng)控制器方案。所提出的PV控制器方案通過使用微控制器來控制升壓轉換器和電池充電器，以便從PV陣列提取最大功率并控制電池的充電過程。本文的目的是提出一種具有成本效益的升壓轉換器設計和用于PV系統(tǒng)的改進的最大功率點跟蹤算法。已經開發(fā)了基于MATLAB的獨立光伏系統(tǒng)的仿真模型，以評估系統(tǒng)在確保最大功率點操作的可行性。1.引言最近，由于環(huán)境、全球變暖、能源安全、技術改進和降低成本有關的問題，PV發(fā)電系統(tǒng)的安裝正在快速增長。光伏發(fā)電系統(tǒng)被認為是一種清潔環(huán)保的能源。光伏系統(tǒng)的主要應用是獨立或并網配置。獨立的光伏發(fā)電系統(tǒng)作為偏遠地區(qū)不可或缺的電源是有吸引力的。然而，PV發(fā)電系統(tǒng)具有兩個主要問題，其涉及約9至12%的低轉換效率，特別是在低照射條件下，并且由PV陣列產生的電功率的量隨天氣條件連續(xù)變化。因此，進行了許多研究工作以增加從PV陣列產生的能量的效率。太陽能電池V-I特性是非線性的，隨著輻射和溫度而變化。但是在V-I和P-V曲線上有一個獨特的點，稱為最大功率點（MPP），在該點PV系統(tǒng)被稱為以最大效率運行并產生其最大功率輸出。MPP的位置是未知的，但可以通過計算模型或搜索算法來跟蹤。因此，需要最大功率點跟蹤（MPPT）技術來將PV陣列的工作點維持在其MPP。在文獻中已經提出了許多MPPT技術，其中技術在許多方面各有不同，包括簡單性、收斂速度、硬件實現(xiàn)和有效范圍。然而，最廣泛使用的MPPT技術是擾動和觀察（P&O）方法。本文提出了一個簡單的MPPT算法，可以輕松實現(xiàn)和采用低成本光伏應用。本文的目的是設計一種改進的MPPT方法的新型PV控制器方案。提出的獨立光伏控制器考慮到實現(xiàn)數(shù)學模型每個組件以及實際的組件規(guī)范。DC-DC或升壓轉換器是連接在PV陣列和負載之間的前端組件。傳統(tǒng)的升壓轉換器可能導致嚴重的反向恢復問題，并增加所有器件的額定值。因此，在這種情況下，轉換效率降低，并且電磁干擾問題變得嚴重。為了提高轉換效率，若干研究人員對許多改進的升壓轉換器拓撲結構進行了研究。電壓鉗位技術已被納入轉換器的設計，以克服輸出二極管的嚴重反向恢復問題。在本文中，重點也是給出升壓轉換器設計。獨立光伏系統(tǒng)的另一個重要組件是充電控制器，用于避免電池由于過多充電和過多放電而可能造成的損壞。研究表明，在不使用充電控制器的情況下，電池的壽命可能會下降。所提出的用于獨立光伏系統(tǒng)的新控制器方案在兩個控制步驟中控制升壓轉換器和充電控制器。第一步是控制升壓轉換器，以提取光伏組件的最大功率點。在這里，高升壓型轉換器被認為是對加強光伏電壓起作用，從而降低了串聯(lián)光伏組件的數(shù)量，并保持一個恒定的直流總線電壓的目的。微控制器用于獲取PV組件工作電流和電壓的數(shù)據采集，也用于對MPPT算法進行編程?？刂破鞑捎妹}沖寬度調制（PWM）技術以隨著PV電壓降低而增加所產生的脈沖的占空比，以便獲得接近最大功率點的穩(wěn)定的輸出電壓和電流。第二控制步驟是為了保護電池而控制充電控制器。通過使用PWM技術控制充電電流并在充電期間控制電池電壓，可以避免高于放氣電壓的電壓。光伏系統(tǒng)設計的提出大多數(shù)獨立的光伏系統(tǒng)僅以一種模式操作，使得光伏系統(tǒng)對電池充電，電池又向負載供電。在這種操作模式中，由于電池的連續(xù)充電和放電，電池的壽命周期時間可能減少。根據圖1中的框圖所示，所提出的獨立的光伏系統(tǒng)被設計成兩種模式操作：光伏系統(tǒng)直接向負載供電，而當輻射下降并且所產生的能量不足時，光伏系統(tǒng)將充電電池，繼而向負載供電。為了管理這些操作模式，通過觀察光伏輸出功率，將控制器連接到升壓轉換器。

團1;克r的團1;克r的蘭伏丟疑示意團1/他MicrocontrollerBaileries計算方法為了估算所提出的獨立光伏系統(tǒng)開發(fā)的數(shù)學模型這一目的，根據MATLAB代碼進行了模擬。在模擬中每個光伏組件考慮在lOOOw/m2、21.2V開路電壓、5A短路電流下的額定功率為