电气工程专业英语+unt2.ppt
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电气工程专业英语+unt2.ppt
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电气工程及其自动化专业英语,主编杨勇邓秋玲,Unit2PowerElectronics,2.1Introduction,2.2PowerSemiconductorDevices,2.3PowerElectronicConverters,2.4FurtherReading:
ElectronicFilters,2.1Introduction,NewWordsandExpressions,solid-stateadj.固态的computationn.计算;估计integrationn.结合;整合;dynamicadj.动态的;n.动力学;mercury-arc医汞弧valven.阀;真空管;semiconductorn.物半导体switchingn.开关;转换;dioden.二极管invertern.反用换流器(逆变器);thyristorn.半导体闸流管;硅可控整流器inverterthyristor晶闸管逆变器;可控硅逆变器transistorn.晶体管;晶体管收音机;半导体收音机transmissionn.播送;传送;信息;传动装置substantialadj.结实的;重大的n.本质;,2.1Introduction,NewWordsandExpressions,fluorescentfl:
resntlampballast荧光灯镇流器mercuryn.水银;汞thermionicadj.物热电子的;HVDCtransmissionsystem高压直流输电系统inductionmotor感应电动机vacuumn.真空;adj.真空的;vt.用真空吸尘器打扫dissipatev.驱散;rectifiern.纠正者;整流器triggeredadj.触发的thyratronartrnn.电闸流管ignitronn.引燃管;放电管cycloconvertern.周波变换器;双向离子变频器triacn.电三端双向可控硅开关元件ascopeof一个范围spectrumn.谱,光谱;能谱;,2.1Introductiontext,Powerelectronicsistheapplicationofsolid-stateelec-tronicsforthecontrolandconversionofelectricpower.Italsoreferstoasubjectofresearchinelectricalengineeringwhichdealswithdesign,control,comput-ationandintegrationofnonlinear,timevaryingenergyprocessingelectronicsystemswithfastdynamics.,Note:
refersto指的是;此句译成:
电力电子技术是电气工程研究课题之一,主要对具有快速动态响应的非线性、时变能源处理的电子系统进行设计、控制、计算和集成。
2.1Introductiontext,Powerelectronicconverterscanbefoundwhereverthereisaneedtochangevoltage,currentorfrequencyofelectricpower,asshowninFig.2.1,Fig.2.2andFig.2.3.Thepowerrangeoftheseconvertersisfromsomemill-iwatts(asinamobilephone)tohundredsofmegawattsinahighvoltagedirectcurrent(HVDC)transmissionsys-tem.,Note:
foundwhereverthereisaneed用在那些需要.的场合,对电压、电流或电能的频率进行转换时,就要用到电力电子转换器。
Note:
powerrangeisfrom.to这些转换器的功率范围从毫瓦特(如移动电话的功率)到高压直流输电系统的数百兆瓦。
2.1Introductiontext,With“classical”electronics,electricalcurrentsandvoltageareusedtocarryinformation,whereaswithpowerelectronics,theycarrypower.Thus,themainmetric主要指标ofpowerelectronicsbecomestheefficiency.,Note:
评价电力电子的主要性能指标是效率。
2.1Introductiontext,Applicationsofpowerelectronicsrangeinsizefromaswitchedmodepowersupplyinanalternatingcurrent(AC)adapter,batterychargers,fluorescentlampballasts,throughvariablefrequencydrivesanddirectcurrent(DC)motordrivesusedtooperatepumps,fans,andmanufactur-ingmachinery,uptogigawatt-scalehighvoltagedirectcurrentpowertransmissionsystemsusedtointerconnectelectricalgrids.,Note:
rangeinsize:
按大小排列.此句译为:
按大小排列,从AC适配器中的开关电源、电池充电器、荧光灯镇流器、到变频驱动和水泵、风机、机床的DC电机驱动,再到用于电网互连、具有千兆瓦规模的高压直流电力传输系统,都能发现电力电子技术的应用。
2.1Introductiontext,Thenin1948theinventionofthebipolarjunctiontransistorbyShockleyallatonce(突然;同时)reducedthecostandsizewhileincreasingtheefficiencyoftransistorsbeginningarevolutioninsemiconductorelectronics.Shortlyafter,inthe1950s,semiconductorpowerdiodesbecameavailableandstartedreplacingvacuumtubes.Thenin1956thesiliconcontrolledrectifier(SCR)wasintroducedbyGeneralElectricmarkingthepointwheresemiconductorpowerelectronicsreallybegan.,Note:
标志着半导体电力电子技术的真正开始:
2.1Introductiontext,Powerelectronicsstartedwiththedevelopmentofmercuryarcrectifier.InventedbyPeterCooperHewittin1902,themercuryarcrectifierwasusedtoconvertACintoDC.In1933selenium(硒)rectifierswereinvented.In1947thebipolarpoint-contacttransistor(双极点接触型晶体管)wasinventedbyWalterHBrattainandJohnBardeenunderthedirectionof(在的领导之下)WilliamShockleyattheBellTelephoneLaboratory.,Note:
startedwith开始于;mercuryarcrectifier汞弧整流器.,2.1Introductiontext,In1960stheswitchingspeedofbipolarjunctiontran-sistors(BJTs)allowedfor(允许)DC/DCconverterstobepossibleinhighfrequency,withthemetaloxidesemi-conductorfieldeffecttransistor(MOSFET)introducedin1960.In1976powerMOSFETbecomescommerciallyavaila-ble.Thenin1982theinsulatedgatebipolartransistor(IGBT)wasintroduced.,Note:
commerciallyavailable市场上能买到的,2.1Introductiontext,Thecapabilitiesandeconomyofpowerelectronicssystemaredeterminedbytheactivedevicesthatareavailable.Theircharacteristicsandlimitationsareakeyelementinthedesignofpowerelectronicssystems.Formerly,themercuryarcvalve,thehigh-vacuumandgas-filleddiodethermionicrectifiers,andtriggereddevicessuchasthethyratronandignitronwerewidelyusedinpowerelectronics.,Note:
aredeterminedby取决于;,Note:
gas-filled充气的;thermionicrectifiers热离子整流器,2.1Introductiontext,Astheratingsofsolid-statedevicesimprovedinbothvoltageandcurrent-handlingcapacity,vacuumdeviceshavebeennearlyentirelyreplacedbysolid-statedevices.Thefirsthighpowerelectronicdevicesweremercury-arcvalves.Inmodernsystemstheconversionisper-formedwithsemiconductorswitchingdevicessuchasdiodes,thyristorsandtransistors,aspioneeredbyR.D.Middlebrookandothersbeginninginthe1950s,Note:
isper-formedwith用.执行,实现;aspioneeredby由.开创的。
2.1Introductiontext,.Incontrasttoelectronicsystemsconcernedwithtransmissionandprocessingofsignalsanddata,inpowerelectronicssubstantialamountsofelectricalenergyareprocessed.AnAC/DCconverter(rectifier)isthemosttypicalpow-erelectronicsdevicefoundinmanyconsumerelectronicdevices,e.g.televisionsets,personalcomputers,batterychargers,etc.,Note:
Incontrastto与.相比;concernedwith涉及此句译为:
电力电子处理大量的电能。
Note:
consumerelectronicdevices消费电子用品。
2.1Introductiontext,Thepowerrangeistypicallyfromtensofwattstoseveralhundredwatts.Inindustryacommonapplica-tionisthevariablespeeddrive(VSD)thatisusedtocontrolaninductionmotor.ThepowerrangeofVSDsstartsfromafewhundredwattsandendattensofmegawatts.Powerelectronicdevicesmaybeusedasswitches,orasamplifiers.,2.1Introductiontext,Anidealswitchiseitheropenorclosedandsodissipatesnopower;itwithstandsanappliedvoltageandpassesnocurrent,orpassesanyamountofcurrentwithnovoltagedrop.Semiconductordevicesusedasswitchescanappro-ximatethisidealpropertyandsomostpowerelectronicapplicationsrelyonswitchingdevicesonandoff,whichmakessystemsveryefficientasnopoweriswastedintheswitchingdevices.,Note:
eitheropenorclosed或打开或关闭;passesanyamountofcurrentwithnovoltagedrop流过电流而不引起压降。
2.1Introductiontext,Bycontrast,inthecaseoftheamplifier,thecurrentthroughthedevicevariescontinuouslyaccordingtoacontrolledinput.Powerelectronicsmakesupalargepartofengin-eeringandhascloseconnectionswithmanyareasofphysics,chemistry,andmechanics.Itestablishesarapidlyexpandingfieldinelectricalengineeringandascopeofitstechnologycoversawidespectrum.,Note:
inthecaseof就.来说;,Note:
makesupalargepart占.大部分;closeconnectionswith与.有紧密联系。
2.2PowerSemiconductorDevicesNewWordsandExpressions,wafern.圆片;晶片SCRn.可控硅整流器GTOn.门极可关断晶闸管MCTn.MOS控制晶闸管IGBTn.绝缘栅双极型晶体管BJTn.双极结型晶体管FETn.场效应管semiconductorn.半导体freewheelingn.惯性滑行adj.惯性滑行的;随心所欲的v.轻快地行动forward-bias正向偏置,2.2PowerSemiconductorDevicesNewWordsandExpressions,kiloamperesn.千安培leakagen.漏,泄漏;漏损量;渗漏物switchn.开关;转换,转换器;vt.&vi.转变,转换reverse-biased反向偏置silicon-controlled可控硅MOSFETn.金属氧化层半导体场效应晶体管gigahertzn.千兆赫enhancementn.增强;增加;提高;改善drawbackn.缺点;不利条件;障碍withstandvt.承受,经得起;反抗vi.反抗;经得起breakdownn.崩溃;损坏,故障;分解;垮,衰竭,Diodes,thyristorsandtransistorsaretheessentialcom-ponentsofthepowerelectronicapplications.Today,thesinglewaferdiodesareabletoblockmorethan9kVoverawidetemperaturerange.Atthesametime,thyristorswithstandmorethan10kV.Thesedevicesconductupto5kA.Thelevelsof6kVand0.6kAareapproachablebypowertransistors.,2.2PowerSemiconductorDevicesTEXT,Note:
essentialcomponents基本元件,关键部件;block阻断,Note:
conduct导电;areapproachable可接近。
Acomparativediagramofpowerratingsandswitchingspeedsofthecontrolledsemiconductorelectronicde-vicesisgiveninFig.2.4.,2.2PowerSemiconductorDevicesTEXT,2.2.1DiodesAsshowninFig.2.5(a),diodesarethemainbuild-ingblocksofrectifiers,rectifiersectionsofACandDCconverters,theirfreewheelingpaths,andmultiplecontrolelectronicunits.Thatiswhyadiodeisthemostcommonlyusedele-ctronicdeviceinthemodernpowerelectronicsys-tems.,2.2PowerSemiconductorDevicesTEXT,Note:
mainbuild-ingblocks主要构件;freewheelingpaths续流路径,Therectifierdiodehasasmallervoltagedropinthefor-ward-biasstate.Theforwardbiascharacteristicofthepowerdiodeisapproximatelylinear,whichmeansthatthevoltagedropisproportionaltotheOhmicresistanceandcurrent.ThemaximumcurrentintheforwardbiasdependsonthePN-junctionarea.Today,theratedcurrentsofpowerdio-desapproachkiloamperes.,2.2PowerSemiconductorDevicesTEXT,Note:
forward-bias:
正向偏置;,Atturnon,thediodecanbeconsideredasanidealswitchbecauseitopensrapidlycomparedtotransientsinthecircuit.Inmostofcircuits,theleakagecurrentdoesnothaveasignificanteffectonthecircuitandthusthediodecanbeconsideredasaswitch.Inthecaseofreverse-biasedvoltage,onlyasmalllea-kagecurrentflowsthroughthediode.,2.2PowerSemiconductorDevicesTEXT,Note:
beconsideredas可看作;leakagecurrent漏电流;,Note:
Inthecaseof,就反向偏置电压而言。
Thiscurrentisindependentofreversevoltageuntilthebreakdownvoltageisreached.Afterthat,thediodevoltageremainsessentiallyconstantwhilethecurrentincreasesdramatically.Onlytheresistanceoftheexter-nalcircuitlimitsthemaximumvalueofthecurrent.Simultaneouslargecurrentandlargevoltageinthebreakdownoperationofthediodemustbeavoided.,2.2PowerSemiconductorDevicesTEXT,Note:
isindependentof与.无关;breakdownvoltage击穿电压;remainsessentiallyconstant基本上不变。
2.2.2ThyristorsandGTOsAsshowninFig.2.5(b),rectifierthyristorsknownassilicon-controlledrectifiers(SCRs)arecommonlyusedinadjustablerectifiercircuits,es
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