光伏跟踪系统智能控制方法的研究

合肥工业大学博士学位论文光伏跟踪系统智能控制方法的研究姓名：徐晓冰申请学位级别：博士专业：电力电子与电力传动指导教师：张崇巍2010-12ZigbeeAbstractBeingthefocusinrelativetechnologicalfields,photovoltaic(PV)powergenerationisalreadyandwillbewidelyappliedascleanandregenerativeenergysource.ThecostofbuildingupaPVpowersystemisstillquiteexpensivethatthatisattributedtothePVdevicesmanufacturedwithsiliconofhighpurity.Moreover,thecapabilityofPVdevicescannotbefullfullyutilizedbecausethesolarenergyischaracterizedoflowenergydensityandrandomness.IntheprogressofPVtechnologyhumanalwaysattempttousetechnicalmeasurestoovercomethosedrawbacks,andsolartrackingandconcentrationarethetwomeasuresthatgetwideattentionandhasbeenexpectedtolargelyreducethecostofthesystemofsamecapacity.Orientedtothetechniqueofsolartracking,somefundamentaltheoreticalstudyismadeinthisdissertation.Thedissertationcommenceswithasummaryofsolarastronomicgeometry,andstudies3methodsofdetectingtherealtimesolarposition.Thestressisputonthemethodofimageprocessing,andproposesamethodthatusestheimagecapturedbyfish-eyelenstolocatethesunandthismethodisverifiedeffective.OrientedtolargecapacityPVsystemanditscontrolstrategy,thedissertationmakesasystematicstudyontheengineeringmathematicalmodelofsiliconPVdevices.Amodelthatadaptstorandomlyvariableworkingconditionisobtainedwiththeusageofthedeviceparametersspecifiedbymanufacturerunderstandardtestconditionandisverifiedinlaboratorywithacceptableaccuracy.Amodelthatincludestheacceptedradiationandthesolaraltitudeisalsoderived.Thosemodelsmaybeusedpreliminaryofthestudyofsystemcontrolstrategy.Amethodofdeterminingthemodelparametersisproposedbyusingthesiliconsolarcells’opencircuitvoltage,shortcircuitcurrentandmaximumpowerpointvoltageandcurrent.Byanalysisofsiliconsolarcellsunderdifferentlightintensitycorrectionmethodofmodelparametersandthesolarelevationangleimpactonthesolarradiation,andthroughstudythechangingloadcurrentsolarcelloutputvoltageundervariouslightintensitytherelationmodelofthetrackinganglesandthesolarcellundertheoutputvoltageisbuildintheconditionofchangingloadcurrent.Thus,theimplementationofoptimalcontrolbasisforPVtrackingsystemissetup.Aquitecompletedesignofamultiphotovoltaicunit(PVU)trackingPVsystembaseonwirelesssensornetworkiscarriedoutinthepreparationofthedissertation.TheintelligentkernelofthePVUisacontrollerdesignedwithembeddingtechnique.ThePVUequippedtwotwo-axesservo-mechanismforsolartracking;sufficientsensorsandtransducersusedtoidentifysolarposition,acquiretheposeofPVarray,measuretheirradiationandenvironmentalparameters;ZigbeewirelessinterfacetosupportthecontrolandoptimizationoflargecapacitynetworkedPVsystem;andgridconnectedinvertedtodeliverenergy.TakingsuchaPVUasbasicunit,thePVsystemcanbeconfiguredwith3approachessuchasindependent,mass-controlledandpilotones.Duetotheuncertaintyandnonlinearity,itishardtosolvethecomplexcontrolofPVsystemwithanalyticalmodelandclassiccontroltheory.Thedissertationstudiesanddevelopsthecontrolstrategybymakingsomeattemptstocombineartificialintelligencewithcontroltheoryandpatternrecognition,amethodbasedontwo-levelbi-directionalcoupledhierachicalstructureisproposedforthefeature-basedmodelingandsmartcontrollerdesign.Andbyusingfinitestatemachinetheory,trackingcontrolofbestreceivedlightintensityunderallweatherisfulfilled.Themethodproposedinthisdissertationhasbeenwellappliedinrelatedprojects.Thedissertationalsoputforwardsomeideasthatmightbefurtherstudied.Keywords:PVgeneratingsystemsolarastronoticgeometrysolartrackingfish-eyeimageidentificationengineeringmodelphotovoltaicunitembeddedsystemhierachicalsystemintelligentcontroliv1-1...................................................................................................71-2...................................................................................................81-3.......................................................................................................91-4.........................................................................101-5.............................................................................................................111-6.....................................................................................111-7.........................................................................................121-8.........................................................................................121-9.................................................................................132-1.................................................................................................172-2.........................................................................................182-3.............................................................................................................................192-4.................................................................................................212-5..........................................................222-6.................................................................................................242-7.........