锂电池组均衡充电与管理系统设计

锂电池组均衡充电与管理系统设计重庆大学硕士学位论文（学术学位）学生姓名：孙朝指导教师：苏玉刚教授专业：控制科学与工程学科门类：工学重庆大学自动化学院二O一三年四月DesignofLi-BatteryChargingEqualizationandManagementSystemAThesisSubmittedtoChongqingUniversityinPartialFulfillmentoftheRequirementfortheMaster’sDegreeofEngineeringBySunZhaoSupervisedbyProf.SuYugangSpecialty:controltheoryandcontrolengineeringCollegeofAutomationofChongqingUniversity,Chongqing,ChinaApril,2013重庆大学硕士学位论文中文摘要I摘要为了解决能源危机和环境污染，各国加大科研投入，促进了电动汽车的快速发展。锂电池以其优越的性能成为电动汽车动力电池的首选，但是对锂电池管理系统也提出了更高要求。为了获得较高的电压和功率，需要将大量锂电池单体串并连接。由于生产工艺的限制，在串联时单体间存在初始容量、内阻、电压等不一致性，使用过程中会导致电池组利用率降低、使用寿命缩短甚至引发安全事故，这些问题成为电动汽车技术发展的瓶颈。本文对锂电池组进行的均衡充电研究和管理系统优化设计有利于推动电动汽车的发展。围绕上述问题本文主要做了以下工作：针对电池组充电电路输出不稳定和充电效率低的问题，通过分析当前几种锂电池组充电方案，设计基于Buck电路的恒流恒压充电电源；根据对锂电池组常用连接方式的分析，得出采用先串后并(S-P)和先并后串(P-S)正常导通概率的数学模型，为分析不同连接方式的可靠性提供了理论依据。针对均衡电路效率低和成本高等问题，分析了当前已有的几种典型均衡方案，以集中多绕组变压器均衡电路为基础，提出改进了均衡电路，该电路具有体积小、结构简单、成本低等特点，给出了改进后电路的数学模型并仿真验证了改进后电路的可行性；基于均衡电路提出改进了均衡控制判定算法。针对荷电状态(SOC，stateofcharge)估算精度低和实现难的问题，分析了当前多种常用SOC估算方案，基于锂电池Thevenin模型，结合扩展卡尔曼(EKF)滤波器原理，建立锂电池SOC估算算法，仿真分析验证了EKF滤波算法可以实现对锂电池组电量的有效估计，能够解决安时积分法初值和开路电压法开路电压难测定的问题。基于上述研究工作，完成了对锂电池管理系统硬软件设计，重点集中在FPGA控制电路设计，检测电路设计和均衡控制子程序设计。关键字：锂电池管理系统、不一致性、均衡、集中式多绕组变压器、SOC重庆大学硕士学位论文英文摘要IIABSTRACTInordertosolveEnergycrisisandenvironmentalpollution,manycountriesincreaseresearchinvestment,promotingtherapiddevelopmentofelectricvehicles,lithiumbatteryisthefirstselectionwithexcellentfunctionforelectricvehicles,butahigherdemandforlithiumbatterymanagementsystem.Inordertoobtainhighvoltageandpower,alargenumberofcellsshouldstringandparallelinconnections.Duetothelimitationsoftheproductionprocess,thecellusedinseries,theinitialcapacity,internalresistance,voltageandotherinconsistencies,causingreducedavailablecapacityofthebatterypack,utilizationfell,severewillshortentheservicelifeofthebatterypackevenproducesafetyincidentandseriousimpedimenttothepopularityofelectricvehicles,itistheimpedimentforthedevelopmentofelectricvehicles.Thelithiumbatterypackequalizingchargeandmanagementsystemoptimizeddesignisconducivetopromotingthedevelopmentofelectricvehicles.Inresponsetotheseproblems,thepapermainlyhasdonethefollowingwork:Foritsoutputunstableandchargingefficiency,thedesignbasedontheBuckcircuitconstantcurrentconstantvoltagechargingpower;Basedontheanalysisoflithiumbatteriescommonlyusedinconnection,concludedthatthefirststringafterparallelandfirstparallelafterstringoftwoconnectionsnormalconductingprobabilisticmathematicalmodel,providesatheoreticalbasisforthereliabilityoftheanalysisofdifferentconnection.Fortheequalizationcircuitlowefficiencyandhighcostproblems,theanalysisoftheexistingseveraltypicalequalizationscheme,focusonmulti-windingtransformercircuitthatwasproposedbasedonimprovedequalizationcircuit,thecircuithasasmallsize,simplestructure,lowcostcharacteristicsandhasgivenmathematicalmodelandsimulationtoverifythefeasibilityoftheimprovedcircuitimprovedcircuit;improvedbalancecontroldecisionalgorithmbasedonstatisticallaws.Inaccordancewithdomesticandinternationalstateofcharge(SOCstateofcharge)Research,analyzeavarietyofcommonlyusedtheSOCestimatetheprogramforitslowestimationaccuracyanddifficultproblem,basedlithiumbatteryTheveninmodel,combinedwiththeextendedKalman(EKF)filteringistheprincipleoftheestablishmentofalithiumbatterySOCestimationalgorithm,simulationanalysistoverifyEKFfilteringalgorithmcanachieveestimatedpowerlithiumbatterypack,can重庆大学硕士学位论文英文摘要IIIsolveproblemsAninitialvalueofintegrationmethodandtheopen-circuitvoltagethemethodopencircuitvoltageisdifficultdeterminationthedifficulttoachieveBasedontheabove-mentionedstudy,thecompletionofthelithiumbatterymanagementsystemhardwareandsoftwaredesign,focusonthedesignoftheFPGAcontrolcircuit,thedesignofthedetectioncircuitandequalized.Keywords:LithiumbatteryManagementsystem,Inconsistency,equalization,multi-windingtransformer,SOC.重庆大学硕士学位论文目录IV目录中文摘要..........................................................................................................................................I英文摘要........................................................................................................................................II1绪论..............................................................................................................................................11.1研究背景及意义.......................................................................................................................11.2国内外研究现状.......................................................................................................................21.2.1均衡电路研究现状............................................................................................................31.2.2荷电状态(SOC)估算研究现状..........................................................................................61.3论文主要研究内容...................................................................................................................71.4本章小结...................................................................................................................................72锂电池模型与