文档名：基于改进等效电路模型的直流微电网大信号稳定性分析
摘要：对高阶非线性直流微电网进行简化建模是大信号稳定性分析的有效方法.传统简化模型主要关注LC滤波器和线路阻抗等参数,难以分析换流器控制参数的影响,所建立的判据存在难以准确反映直流微电网稳定域的问题.因此,该文提出直流电压下垂控制换流器的具备完整状态变量集的改进等效电路模型,相比于传统简化模型,能更准确地刻画系统低频响应特性.基于混合势理论推导了直流微电网大信号稳定判据及其稳定域,并结合LaSalle不变集定理得到能量指标,以反映系统稳定性变化趋势.建立的稳定判据可指导控制参数优化,且能拓展到多端直流微电网的大信号稳定性分析.在多场景下仿真验证了所提改进等效电路模型和大信号稳定判据的有效性.
Abstract：Simplifiedmodelinghasproveneffectiveinanalyzingthelarge-signalstabilityofhigh-ordernonlinearDCmicrogrids(DCMGs).However,thetraditionalsimplifiedmodelsprimarilyfocusontheparameterssuchasLCfiltersandlineimpedances,makingitdifficulttoanalyzetheimpactofconvertercontrolparameters.Additionally,theestablishedcriteriadonotaccuratelyreflectthestabilityregionofDCMGs.Toaddresstheselimitations,animprovedequivalentcircuitmodelwithacompletesetofstatevariablesforDCvoltagedroopcontrolconverterswasproposed.Comparedtothetraditionalsimplifiedmodels,thismodelprovidesamoreaccuratedescriptionofthesystem'slow-frequencyresponse,enablingpreciseanalysisofthelarge-signalstabilityofDCMGs.ThecircuitmodeloftheoutputimpedanceofDCvoltagedroopcontrolconvertersisfirstderivedfromitsoutputvoltagedynamicequation.Subsequently,thismodelundergoesanequivalenttransformation,resultinginanimprovedequivalentcircuitmodelthatincorporatesacompletesetofstatevariablesfortheDCvoltagedroopcontrolconverter.Bycombiningtheimprovedequivalentcircuitmodelwithconstantpowerload(CPL)andparallelresistiveload,anequivalentnonlinearcircuitmodelisderived.Theproposedmodelfacilitatestheconstructionofthemixedpotentialfunction,allowingforthederivationofboththelarge-signalstabilitycriterionandstabilityregionoftheDCMGs.Sothattheparametersdomainandpowerboundaryofthesystemarecalculated.Lastly,theenergyindicatorQthroughtheapplicationoftheLaSalleinvariantsettheoremisobtained,whichhelpstocapturethetrendsinsystemstabilitychanges.Thelarge-signalstabilityofthesystemcanbeassessedbasedontheconditionsofS＜1andPCPL＜PCPLmax,alongwiththedynamicchangesobservedintheenergyindicator.Additionally,thederivedlarge-signalstabilitycriterioncanguidetheoptimizationofcontrolparameters.ThesimulationresultsdemonstratethealignmentbetweentheDCvoltagedynamicresponsesoftheproposedmodelandthoseofthedetailedmodel.TheenergyindicatorreflectsthedegreeoffluctuationintheDCvoltageresponse.Enhancingthelarge-signalstabilityofDCMGscanbeachievedbyincreasingthevoltageloopproportionalandintegralgain,droopgain,filtercapacitanceandlineresistance,whiledecreasinglineinductance.Increasingthedroopgain,lineresistance,andparallelresistiveloadwillresultinareductionoftheCPLboundary.Comparingthelarge-signalstabilitycriteriabasedondifferentmodelingmethodsrevealserrorsintheanalysisresultsobtainedfromtraditionalmodels.Theseerrorsoccurduetothechallengesindescribingthedynamicresponseoftheconvertersadequatelyorwhenthecrucialparametersareoverlookedduringthecalculations.Finally,basedonthesimulationresultsobtainedforbothtwo-terminalandfive-terminalDCMGs,itcanbeseenthatstabilitycanbeachievedintheeventoflargedisturbanceswhenthesystemsatisfiesthemaximumsingularvalueS＜1andwhentheCPLpowervaluePCPLremainsbelowthethresholdofPCPLmax.Conversely,ifthesystemfailstomeetS＜1orPCPL＜PCPLmax,instabilityoccursduringlargedisturbances.
作者：王力 谭振杰 曾祥君 赵斌 郑月球 Author：WangLi TanZhenjie ZengXiangjun ZhaoBin ZhengYueqiu
作者单位：长沙理工大学电气与信息工程学院长沙410114西藏华东水电设备成套有限公司拉萨851414
刊名：电工技术学报
Journal：TransactionsofChinaElectrotechnicalSociety
年，卷(期)：2024, 39(5)
分类号：TM711
关键词：直流微电网 大信号稳定性 等效模型 直流电压控制 混合势理论
Keywords：DCmicrogrid large-signalstability equivalentmodel DCvoltagecontrol mixedpotentialtheory
机标分类号：TM712TM464TM614
在线出版日期：2024年3月19日
基金项目：国家自然科学基金，湖南省自然科学基金项目，长沙理工大学专业学位研究生实践创新与创业能力提升计划资助项目基于改进等效电路模型的直流微电网大信号稳定性分析[
期刊论文] 电工技术学报--2024, 39(5)王力 谭振杰 曾祥君 赵斌 郑月球对高阶非线性直流微电网进行简化建模是大信号稳定性分析的有效方法.传统简化模型主要关注LC滤波器和线路阻抗等参数,难以分析换流器控制参数的影响,所建立的判据存在难以准确反映直流微电网稳定域的问题.因此,该文提...参考文献和引证文献
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基于改进等效电路模型的直流微电网大信号稳定性分析 Large-Signal Stability Analysis for DC Microgrids Based on the Improved Equivalent Circuit Model
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