科技英语英译汉.docx

科技英语英译汉.docx

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科技英语英译汉

科技英语翻译（电子类）

电

磁

波

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文

翻

译

姓名：

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理学院

专业：

电子信息科学与技术

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1.2.1WirelessPowerTransmissionMechanisms

WPTisthetransmissionofelectricalenergyfromapowersourcetooneormoreloadswithoutdirectlyusingsolidwiresorconductors.Itcanbegenerallyclassifiedasradiativeornon-radiativebasedontheenergytransmissionmechanisms.

Intheradiativeorfar-fieldtechnology,alsocalledpowerbeaming,poweristransferredintheformofelectromagneticradiationlikemicrowavesorlaserbeams[5-9].Relyingonthehigh-frequencysignalemissionofapowersource,energycanbetransportedoverlongdistances,whichwouldbemuchgreaterthanthesizeofthetransmittingandreceivingdevicesliketheantenna.Duetotheomni-directionalpropagationofelectromagneticwavesintheair,thetransmittermustbeaimedatthereceivertoincreasetheenergytransmissionefficiency.Inaddition,thepotentialhealthrisksofhumanexposuretoelectric,magnetic,andelectromagneticfieldsintheopenenvironmentareassociatedwithallwirelesspowersystemsfromshortrangetolong-range,lowpowertohighpower,lowfrequency（kHz）tohighfrequency（GHz）,whichlimitthenon-radiatedtechnologyaswell[10-14].

Thenon-radiativeornear-fieldtechnologycantransferpowerwithinshortrangecomparedtoitsradiativecounterpart.Itfurtherfallsintotwofurthercategories,capacitivecouplingandinductivecoupling.Inthecapacitivecouplingtechnology[15-20],poweristransmittedthroughtheelectricfieldbetweenapairofmetalplates,whichformacapacitor.Duetothelimitationsofthehazardousvoltagesimposedontheelectrodesrequiredtotransferacertainamountofpower,itshowsadvantagesonlyinlow-powersmall-air-gap（within1mm）applications,thoughthe

potentialsinkilowatt-levelapplicationshaverecentlybeenreportedin

[19-20].Incontrast,theinductivecouplingtechnology[21-22]makesuseofthemagneticfieldinducedbythealternatingcurrentsinapairofcoils,likeatransformer,whichissuitableforlowtohighpowerlevelsoveralongerenergytransmissiondistance（>1mm）.Duetothefactthatthemagneticcouplingbetweentwoadjacentcoilsinaninductively-coupledWPTsystemisusuallyweak,itspowertransferefficiencywilldroptremendouslyastheair-gapbecomeslonger.

Inordertoincreasetheefficiencyofaninductively-coupledWPT,themagneticresonancetechnologyisused,wherepoweristransferredbythemagneticfieldbetweentworesonantcircuits,oneinthetransmittercoilandtheotherinthereceivercoil.Forexample,onecapacitorisconnectedinserieswiththetransmitterandanothercapacitorisconnectedinparallelwiththereceiver,whichareusedtocompensatetheleakageinductancealongeachpowerflowloopsoastotunethetwocircuitsatthesamedesiredresonantfrequency.Ithasbeenreportedin[23-24]thatusingmagneticresonancecaneffectivelyincreasethe

transmissionrangewhilemaintaininganacceptableefficiency.TherebythistechnologycontributestotherapiddevelopmentofWPTfrom

short-rangetomid-range[25-30]andisadoptedbymostinductiveWPTsystemsnowadays.Thediscussioninthefollowingchapterswillfocusontheinductively-coupledWPTemployingmagneticresonance.

1.2.2Applications

WPTisregardedasapreferablesolutionforcontactlesssupplyofpoweroveracertainair-gap.Duetoitsexclusiveadvantagesofsafety,flexibility,andconvenience,itfindsvariousapplicationsrangingfrommicrowattbiomedicalimplantabledevicestokilowattbatterychargingsystems.

A.Biomedicalimplants.

Biomedicalimplantabledevices,suchasglucosemonitoringimplants,

pacemakers,andcochlearimplantsasshowninFigure1.3,arewidelyusedtomonitordiseases,stimulatehumanorgans,anddelivermedicines.Howevertherisksofthebattery-replacingsurgerywhentheenergystoredisdepletedhasbecomeanissue.Whatismore,thebulkybatteryembeddedintheelectronicdeviceslimitstheminiaturizationoftheimplants,whichhascrucialsignificanceforeffectivenessandpatientsafety.Thetechnologyofwirelesspowering,ortranscutaneousenergytransmission,enablesconvenientwirelesscharging,andevenremovalofthebattery.TheuseofWPTthroughradio-frequencyelectromagneticwavesinbiomedicalapplicationshaskindledsincethe1970s[31-34].Nowadaysithasbeensuccessfullyimplementedinartificialhearts[35-37],cardiacpacemakers[38-40],cochlearimplants[41-42],andothergeneric

biomedicalimplantabledevices[43-45].Severalcontrolmethodshavebeen

reportedin[46-50]tofulfilltheoutputregulationpurposewhilemaintaininghighefficiencyagainstthecouplingandloadingchanges.

B.Consumerelectronics.

OnebigapplicationfieldofWPTliesinconsumerelectronicproducts,

amongwhichthemostsuccessfulcommercializationcaseisthewirelessbatterychargingtechnologyformobilephones[51-57].Theplanarwindingtopologywithachargingsurfaceisregardedasthemostsuitableforthelowpowermobileandwearabledevicechargingaswellasmanyotherconsumerelectronicdevicesofhigherpowerlevels.Despitethefeaturesofsafetyandconveniencecomparedwiththecord-basedchargingmethods,theadoptionofacommonwirelesschargingplatformforarangeofconsumerelectronicshasenvironmentalsignificanceinthatitcanreducethedumpingoftonsofwastedchargers.Figure1.4listssomewirelesschargingproductsavailableonthemarket.

C.Electricvehicles.

Thedevelopmentoftheelectricvehicle（EV）technologyisregardedasaneffectivewaytoreducethegreatdemandforfossilfueldemandandgreenhouseemissions.Despitetheenvironmentalbenefits,EVshavenotgotthebusinesssuccessinthemarketduetothebottleneckofthebatterytechnology.Theinsufficientenergydensity,lowlifetime,andhighcostofLithium-ionbatteries[58-59]whicharecurrentlyusedinmostEVsgreatlyconstraintheoverallperformanceofanEVandcanmakeitunattractivetoconsumers.Forexample,theenergydensityofthecommercializedLithium-ionbatteriesinEVsisonly90–100Wh/kg,whichissopoorcomparedwiththegasoline’s12000Wh/kg.Inaddition,theplug-inchargerhasdisadvantageslikeincreasedrisksinhostile

environments,andreducedreliabilityunderharshclimates,inparticularincoldsnowyzones.Thereforeitisessentialtofindaconvenient,safe,andreliablesolutiontochargeEVs.Inductive-coupledWPTisregardedasapreferredalternative[60-65].

WPTcangetridofthechargingcablesandconnectorsandcontactlesslychargeanEVwhenitisparkedoveraneffectivechargingarea,usingso-calledstationarycharging[66-74].Thetransmitteronthegroundandthereceiveronthevehicleshouldbeaccuratelyalignedtoensurecontinuouspowerflowathighefficiencyinspiteoftheloosecouplingbetweenthetransmittingpadandthereceivingpad.Severalnewstructuresofthechargingpadshavebeenproposedin[69-71,73-74]toenhancethemagneticcouplingandachievegoodtolerancetomisalignment.Investigationsonoptimalcompensationdesignandcontrolmethodshavebeenreportedin[66-68,72]tobuildanefficientwirelesschargingsystem.Figure1.5depictsaprototypicalstationarywirelesschargingsystemwherethebluecircleonthegroundisthetransmittingpad.

Dynamicwirelesscharging,whichmakesuseofelectrifiedroadways,canprovidecontinuouspowertransferwhentheEVismoving,andtherebyreducetheon-boardbatterycapacity[75-84].ThisonlinechargingtechnologycanmakeEVsmorecompetitiveovertraditionalinternalcombustionvehiclesandmorepopularinthemarket.Thedesignconcerningdifferentkindsofpowersupplyrailsalongtheroadbedandassociatedpickupcoilsonthechassisofthecarshasbeenwidelyinvestigated.Figure1.6demonstratestheconceptofadynamicwirelesschargingsystemwheremultiplelumpedcoilsalignedontheroadconstitutethechargingtrackandcanprovidepowersupplywhentheEVispassingoverthemonebyone.

ItisbelievedthattheoverallbatterycapacityofEVswillgrowconsiderablywhentheygetwidelyusedinthenearfuture.AtthattimethewirelessEVchargingsystemwillplayanimportantroleinsmartgridmanagement[85-87].ThebidirectionalWPTtechnology[88-93]canmakeeverysingleEVwhichisindirectlyconnectedtothegridtakepartinpowerflowmanagementinthegridlikeloadbalancingbyvalleyfilling.

D.Othermiscellaneousapplications.

Besidestheaforementioned,WPTcanbewidelyusedinother

applications.Itfindsapplicationsinfactoryautomation,forexampledecentralizedpowersupplyinamanufacturingfloor[94],andcontactlessenergytransmissionforservomotors[95].Aninnovativecompanyhasbeenfoundedtoprovidewirelesslightingsolutions[96].WPTisanefficientwaytoachieveunderwaterpowerdelivery[97-98]andcanbeadoptedinundergroundmining[99-100].Morepotentialapplicationsinchallengingenvironmentsaretobeexploited.

1.2.3SystemDesignConsiderations

ThereareseveralimportantfactorstoconsiderwhiledesigningaWPT

system.Fromthepreviousdiscussion,theconceptofmagneticresonancerequiresacapacitorconnectedwiththecoiltocompensateitsself-inductance,orleakageinductance.InFigure1.7fourbasiccompensationtopologiesarepresenteddependingonhowthecompensatecapacitorsareconnectedwiththecoils,whichareseries-series（SS）,series-parallel（SP）,parallel-series（PS）,andparallel-parallel（PP）,whereL1istheself-inductanceofthetransmitter,R1isthecoilresistanceofthetransmitter,L2istheself-inductanceofthereceiver,R2isthecoilresistanceofthere