变频技术中英文翻译资料

PAGE6PAGE5变频技术1.1变频技术的普及前景电机交流变频调速技术是当今节电、改善工艺流程以提高产品质量和改善环境、推动技术进步的一种主要手段。变频调速以其优异的调速和起制动性能，高效率、高功率因数和节电效果，广泛的适用范围及其它许多优点而被国内外公认为最有发展前途的调速方式。电气传动控制系统通常由电动机、控制装置和信息装置3部分组成，电气传动关系到合理地使用电动机以节约电能和控制机械的运转状态，实现电能-机械能的转换，达到优质、高产、低耗目的。电气传动分成不调速和调速两大类，调速又分交流调速和直流调速两种方式。不调速电动机直接由电网供电，但随着电力电子技术的发展这类原本不调速的机械越来越多地改用调速传动以节约电能(节约15%~20%或更多)，改善产品质量，提高产量。在我国60%的发电量是通过电动机消耗的，因此调速传动是一个重要行业，已经得到国家重视，目前已有一定规模。近年来交流调速中最活跃、发展最快的就是变频调速技术，变频调速是交流调速的基础和主干内容。上个世纪变压器的出现使改变电压变得很容易，从而造就了一个庞大的电力行业。长期以来，交流电的频率一直是固定的，变频调速技术的出现使频率变为可以充分利用的资源。这10年来，变频技术的应用在我国有很大的发展，并取得了良好的效果可以说，变频技术已为大多数用户所接受，但是不能不指出，我国在变频技术的应用方面，与发达国家的水平尚有很大差距，目前，我国在用的交流电动机使用变频调速运行的仅6%左右，而下业发达国家已达(60%~70%)，日本在风机、水泵上变频调速的采用率已达10%,而我国还不足0.01%.在日本，空调器的70%采用了变频调速，而我国才刚刚起步。从这个现实出发，变频技术尚有很大的发展空间，应该锲而不舍地做好推广应用工作。而且随着控制技术和控制手段的不断提高，变频调速又由变压变频控制的变频调速发展到了矢量控制变频调速，通过控制交流电动机里相当于并励直流电动机励磁绕组的磁通变化，提高变频器的恒转矩输出范围和动静态特性，使得交流电动机变频调速系统的性能超过了直流电动机调压调速系统的性能。为了简化控制系统，减少设备故障率，在矢量控制变频调速的基础上又发展了无速度传感器的矢量控制变频调速。在一些对动静态特性要求不太高的应用中，无速度传感器的矢量控制变频调速己完全可以和有速度传感器的矢量控制变频调速相媲美。矢量控制对交流电机调速具有划时代的意义。变频调速是电机调速的最佳方式，是企业技术改造和产品更新换代的理想设备，是工业自动化系统必不可少的组成部分，是实现生产过程和管理自动化的前提，也是信息化发展的先决条件。在我国传统产业中，采用直流电机拖动的调速系统约占调速系统总量的85%~90%，而交流调速系统仅占10%~15%。效率低、质量差、消耗大、故障率高己成为制约企业发展的瓶颈。因此，必须积极推广先进的交流变频调速技术，用先进的设备武装传统产业，促进自动化、工业化和信息化的进一步发展。1.2变频调速发展趋势如果说以第一个晶闸管的出现作为交流电动机变频调速的起点，可以认为它的发展历史己40多年了。而变频调速技术真正高速发展时期，应该是在PWM调制技术的出现和微机控制技术发展之后。特别是最近20年来，随着交流调速技术的应用普及，交流变频调速在化工、火电厂、矿山、油田、机械制造、城市建设、水处理、甚至家电等行业己经全面推广使用，一般主要用于节能及控制。随着变频技术的普及和深入，以及国际、国内电器设备使用的有关标准意识的强化，电力系统行业和用户对变频技术的质量要求也越来越高。变频调速的发展趋势主要围绕下面几个方而展开。1)高性能的智能控制变频器380V系统的低压变频器是国内的主要研究对象，应用交流调速的基本理论，结合神经网络控制、鲁棒控制、模糊控制，或其他智能控制等手段，实现电机运行参数的自动辨识，以期达到自适应、自调整的最优控制。这方面己有一定的研究成果。2)速度传感器研究从前面所述的各种变频调速的理论可知，一般系统都要用到转速传感器。在实际使用中，由于变频设备和被控电动机有一定的距离，而高精度的转速传感器都要使用专门的电源，被控电动机有的是在户外，运行工况非常恶劣，要保证速度反馈的准确性，有时不得不采取特别措施，因此也会增加额外费用，运行的可靠性和控制精度也会因此受到影响。无速度传感器的变频调速系统，是通过现场采集的电流电压量，以及控制的实施策略，综合出被控电机的实际转速。这种控制方案要求计算机的控制速度较高，并有足够的精度。3)针对功率因数提高和谐波污染的研究低压变频调速系统的控制虽然己经是非常成熟了，但目前国际、国内的产品，一般都是矢量控制和直接转矩控制，重点放在电机变频控制理论的实现和完善上，而对变频器的输出波形、功率因数，以及谐波污染等问题还没有引起足够的重视。最近10多年来，国外在这一领域己有较深入的研究。有的针对功率因数，有的强调输出波形。多重化技术就是为了解决输出波形问题。最近几年的研究表明，利用PWM输出控制解决谐波输出问题，是比较理想的方法，它可以省去多重化中的变压器，或过多的开关元器件，使变频器的体积和重量减少，但这种方法不能解决所有谐波的消除问题，只能部分消除特定谐波。这方面的研究论文还不多，也还没有成熟的类似低压变频器的产品出现。4)高压变频器的研究变频器的主要作用之一是节能。而高压电动机的节能效果是比较明显的，大功率的风机和水泵用电动机一般都是高压电动机。国内，高压变频调速和它的节能控制还是一个比较薄弱的环节.它主要是针对6~10kV的交流电动机进行变频调速控制。这种高压电动机广泛应用于火力发电厂的送风机和引风机上。同样也可用于其他如石油化工、矿山、冶炼、ShangYouverybigdisparity.Atpresent,theACmotorsweareusingnowusefrequencyvariationspeedcontrolonlyabout6%,butthedevelopedcountryis60%~70%,Japanonairblower,waterpumpfrequencyconversionvelocitymodulationuserateis10%,butourcountryislessthan0.01%,InJapanair-conditionerusingfrequencyvariationtechniquerateis70%,butourcountry'sonlythenjuststartedEmbarksfromthisreality,frequencyconversiontechnologyremainhavetheverybigdevelopmentspace,weshouldcompletethepromotedapplicationworkdoggedly.Andwiththeconstantdevelopmentofcontroltechniqueandcontrolavenue,frequencyvariationspeedcontrolledhasdevelopedthevectorcontrolledfrequencyvariationvelocitymodulation,bycontrollingtheACmotorinsideactforshuntDCmotorfieldcoper’sflux,toenhancethepermanenttorqueoutputscopeandstaticanddynamiccharacter,maketheACmotorfrequencyvariationspeedcontrolledsystemsuperiortoDCmotorvoltagevariationspeedcontrolledsystem.Forsimplifyingthecontrolsystem,reducingthefaultrate,therehasdevelopedavectorcontrolledfrequencyvariationspeedcontrolwithoutspeedsensorwhichbasedonthevectorcontrolledfrequencyvariationspeedcontrol.Insomeapplicationwhichhavelowrequire,vectorcontrolledfrequencyvariationspeedcontrolwithoutspeedsensorcouldcompletelycomparewiththevectorcontrolledfrequencyvariationspeedcontrolthathavespeedsensor.Thevectorcontrolhastheepoch-makingsignificancetotheACcurrentmotorvelocitymodulation.Frequencyvariationspeedcontrolisthebestwayinthemotorspeedmodulation,itistheperfectgearinthecompany’stechnicalreformandproductrenewal,itistheessentialcompositionintheindustrialautomaticsystem,itistheassumptionofrealizingtheautomaticofproductproceedandmanagement,itisalsothepreconditioninthedevelopmentofinformationization.Inourcountry’straditionalestate,usingtheDCmotorspeedcontrolactuationaccountabout85%~90%inthespeedcontrolledsystem,buttheACspeedcontrolledsystemaccountabout10%~15%.Lowefficiency,badquality,largecost,highfaultratehavealreadybeenthebottleneckthatrestrainthedevelopmentofthecompany.So,wemustpromotetheadvancedACfrequencyvariationspeedcontroltechniquepositively,armsthetraditionalindustrywiththeadvancedequipment,promoteafurtherdevelopmentintheautomation,theindustrializationandtheinformationization.1.2OurCountry’sDevelopmentConditioninSpeedControlledTechniqueOurcountryisadevelopingcountry,somanyproduct’sresearchabilityhasbehindthedevelopedcountries.Fromnowon,theproductoffrequencyvariationspeedcontrolledthatourselvesmadeonlyactforlastcentury90sintheinternational.Withthereformandopening,rapiddevelopmentofeconomic,formsalargemarket,itopenstothecountrycompanies,alsotheforeigncompanies.Manyproductsareexportedfromthedevelopedcountries,andrunswellinourcountry,satisfiedourneedinfabricationandliving.Manyco-partershipcompaniesinourcountrymaketheinternationaladvancedproducts.Thedomesticcompletedepartmentindependentlyisdesigningthemanufactureinthecompletesetinstallmenttousetheforeignimportcompanyandthejointventuresupposesadvancedeach,owndeveloptheapplicationsoftware,canprovidethefirst-classelectricaltransmissioncontrolsystemforthedomesticandforeignimportantengineeringproject.Althoughobtainsverymanyresult,butshouldseebecausedomesticdevelops,theproductionproductabilityvoluntarilyisweak,isserioustotheoverseascompany'sdependence.Asearlyasinthecountry"85"technicalattackplan,thealternatingvelocitymodulationtechniquewaslistedasthekeytechnicalattackproject,butbecauseourcountry’selectricpowerandelectronicdeviceaggregatelevelisverylow,althoughtheproductionofIGBT、GTOcomponenthasintroducedtheoverseastechnique,ithasnotformedtheeconomiesofscalebenefit,almostdoesnothavetheindependentdevelopmentabilityofnewfrequencyconverterproduction,thishasaffectedthedomesticfrequencyconversionvelocitymodulationtechniquedevelopmentinthecertaindegree.InthehighefficiencyAC-ACfrequencyconverttechnique、themotorswithoutcommutatortechniqueandsoon,thedomesticproductalsohasthesuitabledisparityinthedigitizationandthesystemreliableaspectcompareswiththeoverseaslevel,inthemediumefficiencyfrequencyconverttechnique,nearlyallproductionsuseordinaryV/Fcontrolinland,fewadoptthevectorcontroltechnique,andcannotsatisfiedthemarketrequirementinthevarietyandquality.Butinoverseas,thefrequencyconversiontechniqueobtainsthefulldevelopment,andhasobtainedtheremarkableachievementineachaspect.Inpowercomponentaspect,highvoltage、theappearanceofSCR、GTO、IGBT、IGCTwithhighcurrentcapacityandtheusinginseriesandparallel,thehigh-pressuredandhighefficiencyfrequencyconverterproductionobtainstheproductionandthepromotedapplication.Inmicroelectronictechniqueaspect,16bitand32bithighspeedmicroprocessorsaswellasthefastdevelopmentofDSPandASICtechnique,providedthehardwaremethodinrealizingthefrequencyconverterwhichwithhighaccuracymulti-purpose.Intheoryaspect,thevectorcontrol,themagneticfluxcontrol,thetorquecontrol,theintelligentcontrol,thenewcontroltheoryandsoonhaveprovidedtherelatedrationaleforthehighperformancefrequencyconverterdevelopment,wemayseethat,intheoverall,thealternatingfrequencyconversionvelocitymodulationtechniqueinourcountryhasbigdisparitycompareswithinternationallevel.Therefore,theACfrequencyvariationspeedcontroltechniquehasthefollowingsides:1)Thebasicresearchofcontrolstrategyinfrequencyconverterhasalargegapcompareswiththeforeignlevel.2)Thetechnicallevelofthewholemachineislowinthefrequencyconverter,althoughwehadinputcertainlypeople,materialresources,butbecauseofthedispersepower,didnotformacertainlytechniqueandproductionscale.3)Allthesemiconductorpowerdeviceproductinthefrequencyconverterisblank.4)CorrelativeIndustriesandrelativeIndustriesdropbehind.5)Fewproductionandsale,lowreliableandtechnologicalstandards.Withthedevelopmentandimprovementinthepowerelectronictechnique,powerdivertbasedonpowerelectroniccircuittechniqueandvariouscontroltechnique,theACfrequencyvariationspeedcontrolledtechniqueismaturedaybyday,andsuretobethemainwayinthefuture.Withtheconstantdevelopmentofpowerelectronictechnique,reliablecharacter,welladoption,cheappricethatthefrequencyconverterhavewillbecometrue.Thistechniquewillgainwidely,popularityapplication.Atpresent,foreigndevelopedcountries’frequencyconverttechniquetowardstotheminiaturization,highreliability,defendwithharm,morefunction,highcharacter,andourcountryiscomingonnow.1.3FrequencyVariationSpeedControlledModeThealternatingfrequencyconversionvelocitymodulationtechniqueobtainedtherapiddevelopmentin20thcentury.Thisisrelatedwithsomecrucialtechnicalwhichgainunprecedentedprogress,theyareMotorvectorcontroltechnique,Directtorquecontroltechnique,PWMtechnique,Entirenumericalcontroltechniqueandself-settingtechniquewhichbasedonmicrocomputerandlargescaleintegratedcircuit,andsoon.1)VectorControlTechniqueVectortransformationcontroltechniqueisaonekindofnewcontrolthoughtandcontroltheorywhichposedbySIEMENSCO.in1971.Itisrealizingthestatorcurrentexcitationcomponentandthetorquecomponentsolutionlotusrootbyrotormagneticfielddirectiondetection,andvectortransformation,achievedthegoalthatseparatelycontrolthemotorfluxlinkageandtheelectriccurrent,asaresult,obtainfinelystatic,dynamicperformance.Untilnow,thevectorcontroltechniquehasobtainedtheconsiderabledevelopment,andalsoobtainedthewidespreadapplication.2)VectorControlWithoutVelocityGeneratorTechniqueVectorcontrolwithoutvelocitygeneratortechniqueabolishtheproblemsthattheenvironmentcompatibility、installandmaintenancebringon,reducethecost,enhancethesystemreliability,atthesametime,unionvectorcontrol,hasthefineperformanceofvectorcontrol.Thespeedestimatemethodinvectorcontroltechniquewithoutvelocitygenerator,besidesbasismathematicalmodelcomputationelectricmotorrotationalspeed,atpresentthemoreappliedarethemodeltoreferauto-adaptedmethodandexpandstheKalmanfilteringlaw.Inaddition,entireUygurrotormagneticfluxsight,toothovertoneelectricpotential,suchasthistheoryandsoon,alsoappearanceinthevectorcontrolwithoutvelocitygeneratortechnique.Since1983proposedthevectorcontrolwithoutvelocitygeneratortechniquecontrolstrategy,receivestheacademiccirclesandtheindustrialfieldcontinuouslyhighlyfocusedallthetime.HitachicompanyandSichuanelectricalmachineryandsoonhadpublishedtheresearchresultsseparatelyin1987,andhadpromotedtheproductoneafteranother.Atpresent,vectorcontrolwithoutvelocitygeneratortechniqueinfrequencyconvertercontrollinginthevelocitymodulationscopeisabout1:50,someindividualmerchanthas1:75orevenhigherproduct.3)DirectTorqueControlTechniqueIn1985,Germany'sM.Depen-blockproposesthedirecttorquecontroltechnique（DTC）forthefirsttime，Thedirecttorquecontroltechniqueanalyzesthemotormathematicalmodeldirectlyunderthestatorcoordinatesystem.Usesthestatormagneticfielddirectiondetectionbutnottoneedthesolutionlotusrootelectriccurrent，directlycontroltheelectricmotorfluxlinkageandtorque,enablethetorquetoobtainthefastresponse,inordertoobtainthehighlyeffectivecontrolperformance.Directtorquecontroltechniqueisanotherkindofnew、highperformancealternatingfrequencyconversionvelocitymodulationtechniqueaftervectorcontroltechniqueinthenearly10years,thiskindofcontroltechniqueisinsensitivetotheelectricalmachineryparameter,notinfluencebytherotorparameter,easyandfeasible,ithasthebroaddevelopmentandtheapplicationprospect.4)PWM(pulsewidthmodulation)ControlTechniqueIn1964,Germany'sA.Schonungandsomepeopletooktheleadtoproposethepulse-durationmodulation(PWM-pulsewidthmodulation)frequencyconversionthought,openedtherecentdevelopmentdomainforthemodernalternatingvelocitymodulationsystem.ThePWMcontroltechniquecontrolstheinversionoutputalternatingfundamentalwavevoltagepeak-to-peakvaluebychangingtherectanglepulsewidth,controlsitsoutputfrequencythroughchangingthemodulationcycle,inordertocarryontheoutputvoltagepeak-to-peakvalueandthefrequencycontrolontheinversionatthesametime.ThePWMtechniquesimplifiedtheinversionstructure,candistinctlychangetheoutputwaveshapeofthefrequencyconverter,reducestheovertonelossofelectricmotor,andreducesthetorquepulsation,atthesametimeenhancestheperformanceofdynamicresponsesystem.ThePWMtechniquealsomayuseintherectifiercontrolling,canrealizetheinputcurrentwhichapproachesthesineextremely.Andmaycausetheelectricalnetworkpowerfactoris1.ThePWMrectifierthusiscalled“thegreenconverter”.Atpresent,PWMtechniquehasbecomethemostwidespreadcontroltechniqueappliedinthefrequencyconverter.TheunceasinglyvelocitymodulationperformanceofalternatingcurrentmotorisasaresultofthePWMtechniqueunceasingprogressenhancementintheverygreatdegree.AtpresentthewidelyappliesistheoptimizesPWMlawwhichdevelopingbasedontheregularsamplingPWMfoundation,thatisThriceHarmonicSuperposetheoryandvoltagespacevectorPWMtheory.5)NumericalControlTechniqueThedigitalizeincontroltechniqueisthekeytechniqueofstaticfrequencyconversioninstallment,alsowillbethenextdevelopmenttendency,atpresentinthemarketfrequencyconversioninstallmentnearlycomprehensivelyhasrealizedthenumericalcontrol.HasrealizedthefastoperationandthehighaccuracycontrolbyusingtheDSPandtheASICtechnique,andcouldgainafinecurrentwave,