外文翻译--在光伏误差辐射监测能量测量的数据与采样速度.doc

附录SolarEnergyCopyrightElsevierScienceDATASAMPLINGSPEEDVERSUSENERGETICMEASUREMENTERRORSOFIRRADIATIONMONITORINGINPHOTOVOLTAICTokyoUniversityofAgricultureandTechnology,2-24-16,Nakamachi,Koganei-shi,Tokyo184,Japan.(CommunicatedbyGERARDWRIXON.)Abstract:Tomeasuresolarirradiationandphotovoltaicarrayoutputenergyameasuringaccuracycannotbeguaranteedunlessthedatasamplingintervalisappropriatelyselected.Fromthisviewpoint,actualirradiancehasbeenmeasuredbycomparativelyhighspeedsamplingofl-4sfor44monthsandthedailyerrorsofthenumericalintegralhavebeenestimatedforvariousstepsizes.Approximationformulaeoftheerrorversusthestepsizehavebeenstatisticallyobtainedaswellastheirprobabilitydensityfunctioncovering+4c.Finally,anomographispresentedtodecideanappropriatesamplinginterval.Aconcludingexampleshowsthatthedeviatingcomponentoftheerrorexceeding+1%canhappenonceforevery1monthor6monthsifthestepsizeisselectedas105or65.5s,ineachofwhichthetotalerrorbecomes-0.0485k1%or-0.0336&1%includinganaverageerrorcomponentaccordingtothedatameasuredatTsukuba.Copyright1996ElsevierScienceLtd.Introduction:Inaphotovoltaicsystemtheinputsolarenergyhasabasicday-and-nightcycleandanuncertain,timevaryingfactorcausedbymeteorologicalconditions.Whenameasurementisperformedtoobtainlong-termperformanceparameterssuchasirradiation,theamountofgeneratedenergy,etc.,theaccuracyofthemeasurementmaynotbemaintainedifthesamplingspeedofdataacquisitionisdecidedregardlessofthefluctuatingrateofsolarradiation.Sincesimplifiedmeasurementsmayhavetobeadoptedinthefuturewiththespreadofphotovoltaicsystems,someinstructionsmustbeclearlypreparedasasystemmonitoringstandard.Theauthorpresentsananalysisofthisneed.Forthispurpose,actualirradianceprofilehasbeenmeasuredbycomparativelyhighspeedsamplingfor44monthsattheElectro-technicalLaboratoryinTsukubaScienceCity(KurokawaandMine,1989；Kurokawa,1994).Byusingthesedata,thedailyerrorsofnumericalintegrationhavebeenevaluatedforvarioustimestepsizes.Then,theerrorsforeachstepsizehavebeenanalyzedforacertaintermtoobtainstatisticalparameterssuchasstandarddeviation0andaveragevalue.Approximationformulaehavebeenalsogiventoexpressrelationshipsbetweenthesevaluesandstepsizes.Inaddition,theprobabilitydensityfunctionprofileoftheerrorshasbeenalsoestimated.Finally,byapplyingtheapproximationformulaeandtheprobabilitydensityfunction,anomographispresentedfordeterminingamaximumallowablestepsizetoassuremonitoringprecision.DataAcquisition:Inordertoknowthetrueintegralofirradianceprofiles,originalirradiancedataweretakenatacomparativelyhighspeedsamplingratefor44monthsfromSeptember1986toApril1990atTsukubaScienceCity.Thecityislocated60kmnorthofTokyoanditsclimaticconditionsseemtobeordinaryasfarasJapanisconcerned.MeasuringequipmentusedisillustratedinFig.1.Noises,whichmaybegeneratedinsignalconditioners,werealsosuppressedverycarefullybyusinganisolationamplifierandelectronicfilter.Inaddition,adigitalaveragingtechniquesynchronizedwiththeutilitygridfrequencywasadoptedanddrasticallydecreasedthenoiselevel.Morethan100dataweresampledandaveragedforjust40ms,whichcorrespondsto2cyclesofthefrequency.Thisbecomesonesampleofrawdataforthisstudy.TotaldataacquisitionflowisillustratedinFig.2.Thenormalrawdatasamplingperiodwas1sbutitwasmadelonger,upto4s,incaseofaslowerfluctuatingspeedoftheirradiancetoreducedatavolume.Dailydatawerestoredina2HDdiskforeveryday.Byapplyingthetrapezoidalruletothemeasuredirradiancedata,typicalexamplesofwhichareshowninFigs3(a)and4(a),theintegratedvalueofirradiance,i.e.irradiation,siisgivenby.Theintegratingintervalisindicatedbyh.Iterationofeqn(1)givesasdailyintegralofSiuntilti=sunset.Thevariousintervalsaredenotedashjforj=l-60.Thesamplingintervaloftheoriginaldataisho.Therangeofhicorrespondsto10sto2hlogarithmicallyasshowninTable1.S,andSjaregivenasSforh=hoandh=hi,respectively.Then,percentintegrationerror,ejisdefinedby.ThestatisticalvaluesobtainedforacomparativelyshorttermareapttoshowsomeirregularityinthetrendsofstandarddeviationsaspresentedinFig.6.However,itisobservedthattheoverallresultsforthewhole44monthsgaveenoughsmoothnessasshowninFig.9.Therefore,the44monthresultsaretobestudiedasdescribedbelow.ByusingthedatainFig.9,approximationformulaewereformed.AsshowninFigs10and11,therelationshipshowingandcsversushjisdeterminedby.Toobtainenoughprecisionforbothsmallerhregionsandlargerones,two-regionapproximationwasadopted.Forexample,itgivesm=0.0315andd=0.220forh=60andtheirratiostostatisticaldataare1.07and0.980,respectively.Althoughtheformerlooksslightlylarge,thedataofmcontainlargerirregularities.Theyseemtobeareasonableapproximationfordatasmoothing.Probability:Asatentativeconclusionoftheprecedingstatistics,itisunderstoodthatthestandarddeviationofintegrationerrorsismostlyanoteworthyfactorfordetermininganappropriateintegrationinterval.However,itsprobabilisticmeaningisnotpreciselyknownsofar.Thissectionstudiesit.Thefrequencyoftheerrorclassescovering+40atrespectiveintervalshasbeenplottedashistogramsasshowninFigs12-14.Figure12isgivenforh=60s,Fig.13forh=600sandFig.14forh=3600s.Fromthesefigures,itissupposedthattheirdistributionshapesarefairlysimilarinallintervals.Therefore,eachhistogramissuperimposedbynormalizingtheintegrationerrorswitheachstandarddeviation6.ThisresultisgivenasahistograminFig.15.TheGaussiandistributionisalsodrawninthesamefigurebyadottedlineasareference.在光伏误差辐射监测能量测量的数据与采样速度耿介黑川东京大学农业和科技，16年2月24日Nakamachi小金井市，东京184，日本摘要：为了测量太阳辐射和光伏阵列输出能量，除非数据采样间隔是适当选择，否则测量精度无法保证。从这个角度看，实际辐照已被1-4秒的比较高的速度采样测量44个月，用数值积分的每日误差估计各种步长。用逼近公式的误差与步长以及统计学获得其概率密度函数覆盖4。最后，诺模图是决定一个适当的采样间隔。总结的例子表明，偏离误差超过1的组件可以为每1个月或6个月发生一次，如果选择步长为105或65.5s，则总误差变为-0.04851，或-0.03361，其中包括根据筑波测得的数据平均误差分量。版权1996爱思唯尔网络科技有限公司。引言:在太阳能光