文档名：弱电网下基于电网电压前馈的并网逆变器阻抗重塑控制策略
摘要：弱电网下,锁相环在基波以上频段引入的负阻特性,会降低系统输出阻抗的相位,严重影响系统稳定性.鉴于此,该文通过系统控制框图等效变换,推导得到可以消除锁相环负阻特性的电网电压前馈函数,进而提出一种基于电网电压前馈控制的并网逆变器阻抗重塑控制策略.同时,为了提高该策略的普适性,该文利用函数近似和多目标约束为电网电压前馈函数的优化提供两种设计方法,并从系统基波电流跟踪性能、并网功率因数等方面进行误差分析,从而证明其函数优化设计方法的可行性.理论分析表明,优化后的电网电压前馈控制策略,可以有效地对系统输出阻抗相位特性进行重塑,很大程度上拓宽了系统对电网阻抗的适应范围.最后,通过仿真与实验验证所提控制策略的有效性.
Abstract：Underweakgridconditions,thenegativeimpedancecharacteristicsintroducedbythephase-lockedloop(PLL)inthefrequencyrangeabovethefundamentalfrequencycanreducethephaseoftheoutputimpedanceofgrid-tiedinvertersystems,therebyseverelyaffectingthestabilityofthesystem.Additionally,gridvoltagefeedforwardcontrolhasgainedwidespreadattentioningrid-tiedinvertercontrolduetoitssimplicity,effectiveness,andeaseofimplementation.Amongthem,researchongrid-tiedinverterimpedancereshapinghasbeenwidelyapplied.Inordertoseekasimpleandeffectivecontrolstrategytoimprovethestabilityofthesystem,thispaperfocusesonsingle-phaseLCL-filteredgrid-tiedinvertersunderweakgridconditions.Byperformingsystemcontroldiagramequivalencetransformation,thegridvoltagefeedforwardfunctionthateliminatestheimpactofthePLLonthesystem'soutputimpedanceisderived.Subsequently,agridvoltagefeedforwardcontrol-basedgrid-tiedinverterimpedancereshapingcontrolstrategyisproposed.Furthermore,theoptimizationdesignofthegridvoltagefeedforwardfunctionisachievedusingfunctionapproximationandmulti-objectiveconstraintmethods,makingtheproposedcontrolstrategymorefeasibleanduniversallyapplicable.Theanalysisoftherobustnessofgrid-tiedinvertersystemsbasedongridvoltagefeedforwardcontrolshowsthatwhetherusingfunctionapproximationormulti-objectiveconstraintmethods,thiscontrolstrategycanreshapetheinverteroutputimpedance,improvethephaseangleatthecrossoverfrequency,andensurethatthesystemhasaphasemargingreaterthan30°underweakorfragilegridconditions.Itguaranteestherobustnessofthesystemwithoutadditionalphasecompensationstages,andhasnegligibleimpactonthefundamentalcurrenttrackingperformanceofthesystem.Simulationandexperimentalverificationdemonstratethat,regardlessofwhetherfunctionapproximationormulti-objectiveconstraintmethodsareused,thegridcurrentqualityofthesystembasedongridvoltagefeedforwardcontrolhasbeensignificantlyimproved.Thegrid-tiedpointvoltageandcurrentexhibitnophasedeviation,satisfyingtherequirementoftheunitypowerfactorgridconnection.Additionally,thesystemexhibitsexcellentdynamicperformance,effectivelyexpandingtheadaptabilityrangeofgrid-tiedinvertersystemsconsideringthePLLunderweakgridconditions.Theoptimizationdesignmethodofthefeedforwardfunctionbasedonfunctionapproximationfacilitatestheacquisitionofcontrolparameters,greatlyimprovingthefeasibilityofthegridvoltagefeedforwardcontrolstrategy.However,itseffectonreshapingthephasecharacteristicsofthesystem'soutputimpedanceisreduced.Ontheotherhand,themethodbasedonmulti-objectiveconstraintscanadjustandsupplementtheconstraintconditionsaccordingtodifferentengineeringstandardsandspecifications,enablingthefreedesignofthefeedforwardfunctionandenhancingtheuniversalityofthiscontrolstrategy.Itsdrawbackliesinhighcomputationalcomplexityandfeedforwardfunctionparameteracquisition.Inpracticalengineering,themethodselectioncanbemadeaccordingtoactualcircumstances.
作者：杨明 杨倬 李玉龙 朱军Author：YangMing YangZhuo LiYulong ZhuJun
作者单位：河南理工大学电气工程与自动化学院河南省煤矿装备智能检测与控制重点实验室焦作454003
刊名：电工技术学报
Journal：TransactionsofChinaElectrotechnicalSociety
年，卷(期)：2024, 39(8)
分类号：TM464
关键词：弱电网 并网逆变器 阻抗重塑 锁相环 稳定性
Keywords：Weakgrid grid-connectedinverter impedanceremodeling phase-lockedloop stability
机标分类号：TM464TM732TM301.2
在线出版日期：2024年4月29日
基金项目：国家自然科学基金弱电网下基于电网电压前馈的并网逆变器阻抗重塑控制策略[
期刊论文] 电工技术学报--2024, 39(8)杨明 杨倬 李玉龙 朱军弱电网下,锁相环在基波以上频段引入的负阻特性,会降低系统输出阻抗的相位,严重影响系统稳定性.鉴于此,该文通过系统控制框图等效变换,推导得到可以消除锁相环负阻特性的电网电压前馈函数,进而提出一种基于电网电压前馈...参考文献和引证文献
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