大功率LED照明系统的光学设计

论文分类号：2学校代码：10708学号：0809007大功率LED照明系统的光学设计宁磊指导教师姓名：史永胜副教授申请学位级别：硕士专业名称：电力电子与电力传动论文提交日期：2011年3月论文答辩日期：2011年5月学位授予单位和日期：陕西科技大学2011年6月答辩委员会主席：孟彦京评阅人：盲审申请工学硕士学位论文论文题目：大功率LED照明系统的光学设计申请学位学科：工学所学学科专业：电力电子与电力传动培养单位：电气与信息工程学院硕士生：宁磊导师：史永胜副教授2011年5月OPTICALDESIGNOFLIGHTINGSYSTEMWITHHIGHPOWERLEDAThesisSubmittedtoShaanxiUniversityofScienceandTechnologyinPartialFulfillmentoftheRequirementfortheDegreeofMasterofEngineeringByNingLeiThesisSupervisor:ProfessorShiYongshengMay,2011I大功率LED照明系统的光学设计摘要LED被认为是继白炽灯、荧光灯后的第三代照明光源，具有发光效率高、寿命长、无污染、体积小、光方向性强、绿色环保等特点，是未来最有发展潜力的光源之一。但LED发光光方向性较强的特点限制了其在照明领域的应用，如何合理分配LED的能量使其在照明面上照度均匀是一个值得研究的问题，本文主要对LED的光学设计进行了研究。首先，对LED进行了一次光学设计，利用TracePro软件模拟分析研究了封装结构对LED出光率的影响，研究结果表明：封装腔体的形状与出光率关系不大，而封装腔体的张角、封装腔体顶面的凹凸性与出光率有较大关系，另外出光率还与腔体的高度、封装腔体的反射率、腔体的母线均相关。其次，运用区域叠加和优化设计相结合的方法对LED进行二次光学设计，用Tracepro软件模拟了使用该反射器的LED路灯照度分布及光强分布，最后实验验证了此反射器可以用于大功率LED路灯，研究结论是运用转移中心光强的方法可以设计大功率LED路灯反射器。第三，讨论了偏微分方程法构造自由曲面透镜的原理，根据折射定律，对LED照明光学系统进行了数学建模，分析了偏微分方程构造自由曲面透镜的过程。由于求解此偏微分方程比较复杂，还将有待理论进一步的研究。最后，运用能量守恒划分网格法构造自由曲面透镜；此方法的数学思想是通过建立光源和照明面之间的映射关系，对光源和照明面区域进行离散化，进行对每条光线能量的跟踪，计算出发射光线的发射方向，结合折射定律求解自由曲面。运用软件对其数学思想进行编程，通过此方法求解出了自由曲面透镜，并对单颗透镜进行了模拟分析，照度均匀性较好，70%以上的能量集中到了照明目标区域，同时绘制了自由曲面透镜的三视图。关键词：发光二极管，出光率，反射器，自由曲面透镜IIOPTICALDESIGNOFLIGHTINGSYSTEMWITHHIGHPOWERLEDABSTRACTLightemittingdiode(LED)wasconsideredas3-Genlighttingsourcesinceincandescentandfluorescentlamp,whichhadmeritsofhighluminousefficiency,longlifetime,nopollutions,smallsize,strongdirectivityandenvironmentalfriend.LEDisthemostpromisingandperspectivelightsourceinthefuture.ButLEDlightsource’scharacteristicsconfineditsapplicationinlightingfield.ItisaquestionwhichisdeservedtobestudiedthathowtoallocatetheLEDpowerrationallytoformtheidealluminanceonthetargetplane.TheopticaldesignisofessentialimportanceinapplicationofLEDaslightsource,sotheworkfocusonresearchesonrelativeopticaldesign.Firstly,generally,LEDopticaldesignincludestwoparts,the1st(packaging)andthe2ndopticaldesign.The1stopticaldesignwasperformedfirstlyinthiswork,theinfluenceofpackagestructureonthelightextractionofLEDwerepresentedbysimulationswithTracePro.Theresultsshowedthattheshapeofpackagecavityhaslittleeffectonlightoutcouple,however,packagecavityopen-angleandtheconvexityoftopsurfacecloselyarerelatedtolightextractions.Inaddition,thelightextractionisrelatedwiththeheightofcavity,thereflectivityaswellascavitybus.Secondly,withregionalsuperpositionandoptimizationapproaches,the2ndopticaldesignforLEDwasprocessedandilluminationandintensitydistributionsweresimulatedbyTraceProwhenaspecialreflectorwasapplied.Experimentsprovedthatthereflectorcanbeusedinstreetlampwithhigh-powerLED,moreover,themethodoftransferingthecentralintensitywassuggestedtohelpthedesignofHPLEDstreetlampreflector.Thirdly,constructionprincipleoffreesurfacelens,basingonpartialdifferentialequations,wasfurtherdiscussed.Accordingtothelawofrefraction,LEDilluminationopticalsystemwasmathematicallymodeled,thefreesurfacelenswasobtainedonthebasisofcertainboundaryconditions.Asthispartialdifferentialequationisquitecomplex,furtherresearchesshouldbeprocessed.Finally,afreeformlenswasconstructed,usingidealoftheenergyIIIconservationingrid.Theidealwasbasedonthemathmaticalfunctionsbetweenthelightsourceandilluminativeplane.Atfirst,discretionoflightsourceandplanewasperformed,then,energyofbeamswasfollowedtocancultedthedirectionsofbeam,eventually,thelenswasobtainedviarefractionlaw.Thewholeprocesswasgrammerizedusingrelativesoftwares,andtheeffectssinglelenswassimulted,theresultsmeetwiththelightingrequirements.Thereismorethan70%lightingenergyinthetargetarea,whiledrawingthethreeviewsoffreeformlen.KEYWORDS:LED,lightingextraction,reflector,freeformlenI目录摘要..........................................................................................................................................IABSTRACT...............................................................................................................................II1绪论.........................................................................................................................................11.1课题背景及意义............................................................................................................11.1.1LED发展历史回顾.............................................................................................11.1.2国内外发展现状.................................................................................................21.2LED照明特点及应用...................................................................................................31.2.1LED照明优点.....................................................................................................31.2.2LED的应用.........................................................................................................41.3本科题研究内容...........................................................................................................52LED发光机理及照明设计.....................................................................................................62.1LED发光机理......................