光伏储能系统的协调控制策略研究

北方工业大学硕士学位论文I光伏储能系统的协调控制策略研究摘要光伏发电作为利用太阳能的一种昀广泛的应用方式，近年来成为各国学者开发研究的热点。系统协调控制策略是改善系统性能和提高能量利用率的核心技术，是光伏储能系统研究中的关键问题。本文以共直流母线式的光伏储能系统作为研究对象，深入研究了系统的能量管理方案和不同电力电子变换器的控制具体方法，具有重要的理论研究和实际应用意义。在以往传统的系统能量管理方案中，当系统环境变化恶劣时，极容易造成蓄电池的过充和过放，从而损坏蓄电池，降低蓄电池寿命，大大增加了系统成本，严重时甚至会使系统不能正常工作。针对上述问题，本文制定了一整套完整的能量管理方案，其中包括系统工作模式的划分，边界条件的制定，提出了具体每种模式下的控制方法，不同工作模式之间的平滑切换情况。该种方案考虑到了蓄电池充满以及缺电的情况，保护了蓄电池，使光伏储能系统适用范围更强、应用范围更广。针对以往光伏储能系统中电力电子变换器所采用的闭环控制方法(PI调节器)存在的调节器参数多不易实现、控制结构复杂等缺点。本文借鉴了模型预测控制(MPC)思想，提出了基于模型预测的MPPT控制方法和两种基于模型预测的蓄电池充放电控制方法，该方法主要通过建立预测模型对系统目标量的下一时刻的所有可能值进行预测，拟定目标函数，选择使函数昀小的开关状态来控制电力电子变换器开关管。模型预测方法控制结构简单、控制灵活、对调节参数不敏感，系统动静态性能优良。本文搭建了一套蓄电池充放电实验平台，在该平台上首先实现了储能变换器的双闭环控制(PI调节器)，实验结果表明该系统通过蓄电池有效充放电可以实现母线电压稳定；同时也验证了蓄电池恒流充电以及放电过程的模型预测控制方法的有效性，具有很好的动态性能；昀后通过模型预测方法控制储能变换器实现了母线电压的稳定，与双闭环控制相比，具有更快的充放电切换速度。     关键词：光伏储能系统，能量管理方案，DC/DC变换器，闭环控制，模型预测控制北方工业大学硕士学位论文IIResearchonCoordinateControlStrategyofPhotovoltaicEnergyStorageSystemABSTRACT  Photovoltaicpowergenerationisoneofthemostwidelyusedwaysofutilizingsolarenergy.Ithasbeenbecomingscholars’mainresearchanddevelopmenthotspotinrecentyears.Coordinatecontrolstrategyisthecoretechnologytoimprovethesystemperformanceandenergyefficiencyandisalsothecoreresearchquestionofphotovoltaicenergystoragesystem.Thispaperintroducesthephotovoltaicenergystoragesystembasedonthecommondcbusastheresearchobject.Itmakesin-depthresearchforthesystem’senergymanagementschemeandthedifferentpowerconvertercontrolmethod.Ithasimportanttheoreticalandpracticalsignificance.Intraditionalsystemenergymanagementplan,whenthesystem’senvironmentisbadlychanging,itisextremelyeasytocausethechargeanddischargeofbatteryanddamagetothebattery,alsoreducethebatterylife,increasethesystemcostandevenmakethesystemstopworkingseriously.Accordingtotheaboveproblems,thispaperestablishesasetofcompleteenergymanagementsolutions,includingthedivisionofsystemworkingmode,theboundaryconditions,alsoputtingforwardthespecificenergymanagementsolutionsforeachmode,smoothswitchingbetweendifferentworkingmode.Thisschemetakesintoconsiderationofpowerfullandpowershortagesituationtoprotectthebattery.Itmakesphotovoltaicenergystoragesystemhavestrongapplicablescopeandwideapplicationrange.Theeveradoptedcontrolmethodofthepowerelectronicconverterinphotovoltaicenergystorageistheclosed-loopcontrol(PIcontroller).Thiscontrolmethodhastoomanycontrollerparameterstoadjustandcontrolstructureiscomplex.Inthispaper,byusingthemodelpredictivecontrol(MPC),MPPTcontrolmethodandtwokindsofstoragebatterycharginganddischargingcontrolmethodsbasedonthemodelpredictionsareproposed.Thismethodismainlyestablishingpredictivemodelofsystemtargettopredictallthepossiblevaluesofthenextmoment,andalsoformulatingtheobjectivefunctiontochoosetheswitchstateofthepowerelectronicconvertertobeminimized.Themodelpredictivecontrolmethodhassimplestructure,flexiblecontrolandisnotsensitivetoadjustingparameters,alsohasgooddynamicandstaticperformance.Thispaperdesignsasetofstoragebatterycharginganddischargingexperimentalplatform.Theplatformfirstlyrealizesthedoubleclosed-loopcontrol(PIcontroller)ofstoredenergyconverter.Theexperimentalresultsshowthatthedcbusvoltageisstablethroughthebatterychargingand北方工业大学硕士学位论文IIIdischargingandalsorealizetheconstantcurrentcharginganddischargingofthebattery.Atthesametime,itrealizestheconstantcurrentcharginganddischargingofthebatterywithmodelpredictivecontrolhavingagooddynamicperformance.Atlast,themodelpredictivecontrolmethodcontrolsthestoredenergyconvertertorealizethestabilityofthedcbusvoltage.Comparedwiththedoubleclosed-loopcontrol,ithasaspeedofswitchingbetweencharginganddischargingmodes.     KEYWORDS：PhotovoltaicEnergyStorageSystem,EnergyManagementScheme,DC/DCconverter,Closed-loopControl,ModelPredictiveControl北方工业大学硕士学位论文1目录光伏储能系统的协调控制策略研究....................................................................................................I摘要....................................................................................................................................................IResearchonCoordinateControlStrategyofPhotovoltaicEnergyStorageSystem.............................II1绪论....................................................................................................................................................11.1选题背景和意义.....................................................................................................................11.2光伏储能系统结构.................................................................................................................21.3光伏储能系统组成.................................................................................................................41.4光伏储能系统控制技术及发展历程.....................................................................................71.5论文的主要内容.....................................................................................................................92光伏储能系统的传统协调控制策略..............................................................................................112.1系统的能量管理方案...........................................