电气工程及其自动化专业英语第一章课文翻译
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Section 1 Introduction 第一节介绍The modern society depends on the electricity supply more heavily than ever before.现代社会比以往任何时候对电力供应的依赖更多。
It can not be imagined what the world should be if the electricity supply were interrupted all over the world. 如果中断了世界各地的电力供应,无法想像世界会变成什么样子Electric power systems (or electric energy systems), providing electricity to the modern society, have become indispensable components of the industrial world. 电力系统(或电力能源系统),提供电力到现代社会,已成为产业界的不可缺少的组成部分。
The first complete electric power system (comprising a generator, cable, fuse, meter, and loads) was built by Thomas Edison –the historic Pearl Street Station in New York City which began operation in September 1882. 托马斯爱迪生建立了世界上第一个完整的电力系统(包括发电机,电缆,熔断器,计量,并加载)它就是位于纽约市具有历史意义的珍珠街的发电厂始于1882年9月运作。
This was a DC system consisting of a steam-engine-driven DC generator supplying power to 59 customers within an area roughly 1.5 km in radius. The load, which consisted entirely of incandescent lamps, was supplied at 110 V through an underground cable system. 这是一个直流系统,由一个蒸汽发动机驱动的直流发电机其供电面积约1.5公里至59范围内的客户。
第一章 电路基本原理第一节 电流与电压u (t )和i (t )这两个变量是电路中最基本的概念,描述了电路中各种不同的关系。
电荷与电流电荷与电流的概念是解释一切电气现象的基础原则。
而电荷也是电路的最基本的量。
电荷是构成物质的原子的电气属性,单位是库仑(C )。
通过基础物理学,我们了解到一切物质都是由被称为原子的基本粒子构造而成的,每个原子中都包含电子、质子和中子。
我们还知道电子上的电荷带负电,每个电子上的电量是1.60210×10-19库仑。
质子带与电子相等的正电荷。
原子上质子与电子的数目相等,使其呈中性。
我们来考虑电荷的运动。
电或电荷的独特之处就是它们可以移动,也就是说电荷可以从一个地方移动到另一个地方,从而转换成另外一种形式的能量。
当把一根导线接在电池(一种电源)的两端时,电荷受迫而运动;正电荷与负电荷分别向相反的两个方向移动。
这种电荷的移动产生了电流。
习惯上,我们把正电荷移动的方向或负电荷移动的反方向称为电流的方向,如图1-1所示。
这种说法是由美国科学家、发明家本杰明·富兰克林提出的。
即使我们知道金属导体中的电流是由于带负电荷的电子(运动)而产生的,(我们)也使用默认的习惯,将正电荷运动的方向定义为电流的方向。
因此,电流是单位时间内电荷的变化率,单位是安培(ampere ,A )。
在数学上,电流i 、电荷q 和时间t 的关系为i=dtdq (1-1) 将等式的两边同时进行积分,则可得到电荷在时间t 和t 0之间的变化。
有q== 0t t idt (1-2)在等式(1-1)中我们给电流i 的定义表现了电流不是一个定值量,电荷随时间的变化不同,电流也与之呈不同的函数关系。
电压、电能与电功率使电子在导体中定向运动需要做功或能量转换。
功由外电动势提供,最典型的就是图1-1中的电池。
外电动势也可理解为电压或电位差。
电路中,a 、b 两点之间的电压U ab 等于从a 到b 移动单位电荷所需能量(所做的功),有U ab =dqdw (1-3) w 代表电能,单位是焦耳(J );q 代表电量。
第一章第一篇sectiongTwo variables u(t) and i(t) are the most basic concepts in an electric circuit, they characterize the various relationships in an electric circuitu(t)和i(t)这两个变量是电路中最基本的两个变量,它们刻划了电路的各种关系。
Charge and CurrentThe concept of electric charge is the underlying principle for explaining all electrical phenomena. Also, the most basic quantity in an electric circuit is the electric charge. Charge is an electrical property of the atomic particles of which matter consists, measured in coulombs (C). 电荷和电流电荷的概念是用来解释所有电气现象的基本概念。
也即,电路中最基本的量是电荷。
电荷是构成物质的原子微粒的电气属性,它是以库仑为单位来度量的。
We know from elementary physics that all matter is made of fundamental building blocks known as atoms and that each atom consists of electrons, protons, and neutrons. We also know that the charge e on an electron is negative and equal in magnitude to 1.60210×10 19C, while a proton carries a positive charge of the same magnitude as the electron. The presence of equal numbers of protons and electrons leaves an atom neutrally charged. 我们从基础物理得知一切物质是由被称为原子的基本构造部分组成的,并且每个原子是由电子,质子和中子组成的。
注:电气工程及其自动化专业英语翻译 1~7面班级:1002班学号:20姓名:王定瑞PART 1 FUNDAMENTALS OF ELECTRIC ENGINEERINGChapter 1 Circuit Fundamentals第1部分的电气工程基础第1章电路原理Electrostatic Charges静电荷Protons and electrons are parts of atoms that make up all things in our world. The positive charge of a proton is similar to the negative charge of an electron. However, a positive charge is the opposite of a negative charge. These charges are called electrostatic charges. Each charged particle is surrounded by an electrostatic field.质子和电子部件的原子构成一切事物在我们的世界。
正电荷的质子是类似于负电荷的电子。
然而,一个正电荷的反面是一个负电荷。
这些指控被称为静电荷。
每个带电粒子周围是一个静电场。
The effect that electrostatic charges have on each other is very important. They either repel (move away) or attract (come together) each other. It is said that like charges repel and unlike charges attract.这个效应,静电指控对方是非常重要的。
他们要么排斥(离开)或吸引(一起)每个其他。
Section 1 Introduction 第一节介绍The modern society depends on the electricity supply more heavily than ever before.现代社会比以往任何时候对电力供应的依赖更多。
It can not be imagined what the world should be if the electricity supply were interrupted all over the world. 如果中断了世界各地的电力供应,无法想像世界会变成什么样子Electric power systems (or electric energy systems), providing electricity to the modern society, have become indispensable components of the industrial world. 电力系统(或电力能源系统),提供电力到现代社会,已成为产业界的不可缺少的组成部分。
The first complete electric power system (comprising a generator, cable, fuse, meter, and loads) was built by Thomas Edison –the historic Pearl Street Station in New York City which began operation in September 1882. 托马斯爱迪生建立了世界上第一个完整的电力系统(包括发电机,电缆,熔断器,计量,并加载)它就是位于纽约市具有历史意义的珍珠街的发电厂始于1882年9月运作。
This was a DC system consisting of a steam-engine-driven DC generator supplying power to 59 customers within an area roughly 1.5 km in radius. The load, which consisted entirely of incandescent lamps, was supplied at 110 V through an underground cable system. 这是一个直流系统,由一个蒸汽发动机驱动的直流发电机其供电面积约1.5公里至59范围内的客户。
1```In the generator mode ,it,s operating speed isslightly higger than it,s synchronous speed and ie needs magnetizing revctive pover form the symtem that it is connected to in order to suuply pover .在发电方式下他的工作速度比同步转速稍高些,并了解供电力,他需要他所连接的系统吸收磁化无功功率。
2```in the barking mode of operyetion ,a three –phase indection motor running at a steady –speedcan be brought to a quick stop by interchanging two of stator leads感应电机运行电动状态时,其转速低于同步转速,运行在发电状态时,其转速高于同步转速,这就需要从与之间相连的系统电源提供励磁的无功功率。
3```obviously ,dc machine applications are very significant,but the advantages of the dc machinemmust be weighed against its greatr initial investment cost and the maintenance problems associated with its brush-commutator system..同步是指状态运行时点击以恒定的转速和频率运行。
4```with a cylindyical rotor the reluctance of the magnetic circuit of the field is independent of itsactual diretion and relative to the direct axis.圆柱形转子的磁场磁路的磁阻与直轴有关,而与磁场的实际方向无关。
电气工程及其自动化专业英语翻译.Electric Power Systems.The modern society depends on the electricity supply more heavily thanever before. It can not be imagined what the world should be if the electricity supply were interrupted all over the world. Electric power systems (or electric energy systems), providing electricity to the modern society, have become indispensable components of the industrial world. The first complete electric power system (comprising a generator, cable, fuse, meter, and loads) was built by Thomas Edison –the historic Pearl Street Station in New York City which began operation in September 1882. This was a DC system consisting of a steam-engine-driven DC generator supplying power to 59 customers within an area roughly 1.5 km in radius. The load, which consisted entirely of incandescent lamps, was suppliedat 110 V through an underground cable system.. Within a few years similar systems were in operation in most large cities throughout the world. Withthe development of motors by Frank Sprague in 1884, motor loads were addedto such systems. This was the beginning of what would develop into oneof the largest industries in the world. In spite of the initial widespreaduse of DC systems, they were almost completely superseded by AC systems. By 1886, the limitations of DC systems were becoming increasingly apparent. They could deliver power only a short distance from generators. To keep transmission power losses ( I 2 R ) and voltage drops to acceptable levels, voltage levels had to be high for long-distance power transmission. Such high voltages were not acceptable for generation and consumption of power; therefore, a convenient means for voltage transformation became a necessity.The development of the transformer and AC transmission by L. Gaulard and JD Gibbs of Paris, France, led to AC electric power systems. In 1889, the first AC transmission line in North America was put into operation in Oregon between Willamette Falls and Portland. It was a single-phase line transmitting power at 4,000 V overa distance of 21 km. With the development of polyphase systems by Nikola Tesla, the AC system became even more attractive. By 1888, Tesla held several patents on AC motors, generators, transformers, and transmission systems. Westinghouse bought the patents to these early inventions, and they formed the basis of the present-day AC systems. In the 1890s, there was considerable controversy over whether the electric utility industry should be standardized on DC or AC. By the turn of the century, the AC system had won out over the DC system for the following reasons:(1)V oltage levels can be easily transformed in AC systems, thus providing the flexibility for use of different voltages forgeneration, transmission, and consumption.(2)AC generators are much simpler than DC generators.(3)AC motors are much simpler and cheaper than DC motors.The first three-phase line in North America went into operation in 1893.——a 2,300 V, 12 km line in southern California. In the early periodof AC power transmission, frequency was not standardized. This poses a problem for interconnection. Eventually 60 Hz was adopted as standardin North America, although 50 Hz was used in many other countries. The increasing need for transmitting large amounts of power over longer distance created an incentive to use progressively high voltage levels.To avoid the proliferation of an unlimited number of voltages, theindustry has standardized voltage levels. In USA, the standards are 115, 138, 161, and 230 kV for the high voltage (HV) class, and 345, 500 and 765 kV for the extra-high voltage (EHV) class. In China, the voltage levels in use are 10, 35, 110 for HV class, and 220, 330 (only in Northwest China) and 500 kV for EHV class . The first 750 kVtransmission line will be built in the near future in Northwest China. With the development of the AC/DC converting equipment, high voltage DC (HVDC) transmission systems have become more attractive and economical in special situations. The HVDC transmission can be used for transmissionof large blocks of power over long distance, and providing an asynchronouslink between systems where AC interconnection would be impracticalbecause of system stability consideration or because nominal frequenciesof the systems are different. The basic requirement to a power systemis to provide an uninterrupted energy supply to customers with acceptablevoltages and frequency. Because electricity can not be massively storedunder a simple and economic way, the production and consumption ofelectricity must be done simultaneously. A fault or misoperation in anystages of a power system may possibly result in interruption ofelectricity supply to the customers. Therefore, a normal continuousoperation of the power system to provide a reliable power supply to the customers is of paramount importance. Power system stability may bebroadly defined as the property of a power system that enables it to remainin a state of operating equilibrium under normal operating conditionsand to regain an acceptable state of equilibrium after being subjectedto a disturbance.. Instability in a power system may be manifested inmany different ways depending on the system configuration and operatingmode. Traditionally, the stability problem has been one of maintaining synchronous operation. Since power systems rely on synchronous machinesfor generation of electrical power, a necessary condition forsatisfactory system operation is that all synchronous machines remainin synchronism or, colloquially in step. This aspect of stability isinfluenced by the dynamics of generator rotor angles and power-angle relationships, and then referred to rotor angle stability译文:电力系统现代社会比以往任何时候更多地依赖于电力供应。
电气工程及其自动化专业英语翻译(精选多篇)第一篇:电气工程及其自动化专业英语翻译Electric Power Systems.The modern society depends on the electricity supply more heavily than ever before.It can not be imagined what the world should be if the electricity supply were interrupted all over the world.Electric power systems(or electric energy systems), providing electricity to the modern society, have become indispensable components of the industrial world.The first complete electric power system(comprising a generator, cable, fuse, meter, and loads)was built by Thomas Edison – the historic Pearl Street Station in New York City which began operation in September 1882.This was a DC system consisting of a steam-engine-driven DC generator supplying power to 59 customers within an area roughly 1.5 km in radius.The load, which consisted entirely of incandescent lamps, was supplied at 110 V through an underground cable system..Within a few years similar systems were in operation in most large cities throughout the world.With the development of motors by Frank Sprague in 1884, motor loads were added to such systems.This was the beginning of what would develop into one of the largest industries in the world.In spite of the initial widespread use of DC systems, they were almost completely superseded by AC systems.By 1886, the limitations of DC systems were becoming increasingly apparent.They could deliver power only a short distance from generators.To keep transmission power losses(I 2 R)and voltage drops to acceptable levels, voltage levels had to be high for long-distance power transmission.Such high voltages were not acceptable for generation and consumption of power;therefore, a convenient means for voltage transformationbecame a necessity.The development of the transformer and AC transmission by L.Gaulard and JD Gibbs of Paris, France, led to AC electric power systems.In 1889, the first AC transmission line in North America was put into operation in Oregon between Willamette Falls and Portland.It was a single-phase line transmitting power at 4,000 V over a distance of 21 km.With the development of polyphase systems by Nikola Tesla, the AC system became even more attractive.By 1888, Tesla held several patents on AC motors, generators, transformers, and transmission systems.Westinghouse bought the patents to these early inventions, and they formed the basis of the present-day AC systems.In the 1890s, there was considerable controversy over whether the electric utility industry should be standardized on DC or AC.By the turn of the century, the AC system had won out over the DC system for the following reasons:(1)Voltage levels can be easily transformed in AC systems, thusproviding the flexibility for use of different voltages for generation, transmission, and consumption.(2)AC generators are much simpler than DC generators.(3)AC motors are much simpler and cheaper than DC motors.The first three-phase line in North America went into operation in 1893——a 2,300 V, 12 km line in southern California.In the early period of AC power transmission, frequency was not standardized.This poses a problem for interconnection.Eventually 60 Hz was adopted as standard in North America, although 50 Hz was used in many other countries.The increasing need for transmitting large amounts of power over longer distance created an incentive to use progressively high voltage levels.To avoid the proliferation of anunlimited number of voltages, the industry has standardized voltage levels.In USA, the standards are 115, 138, 161, and 230 kV for the high voltage(HV)class, and 345, 500 and 765 kV for the extra-high voltage(EHV)class.In China, the voltage levels in use are 10, 35, 110 for HV class, and 220, 330(only in Northwest China)and500 kVforEHVclass.Thefirst750kVtransmission line will be built in the near future in Northwest China.With the development of the AC/DC converting equipment, high voltage DC(HVDC)transmission systems have become more attractive and economical in special situations.The HVDC transmission can be used for transmission of large blocks of power over long distance, and providing an asynchronous link between systems where AC interconnection would be impractical because of system stability consideration or because nominal frequencies of the systems are different.The basic requirement to a power system is to provide an uninterrupted energy supply to customers with acceptable voltages and frequency.Because electricity can not be massively stored under a simple and economic way, the production and consumption of electricity must be done simultaneously.A fault or misoperation in any stages of a power system may possibly result in interruption of electricity supply to the customers.Therefore, a normal continuous operation of the power system to provide a reliable power supply to the customers is of paramount importance.Power system stability may be broadly defined as the property of a power system that enables it to remain in a state of operating equilibrium under normal operating conditions and to regain an acceptable state of equilibrium after being subjected to a disturbance..Instability in a power system may be manifested in many different ways depending on the system configurationand operating mode.Traditionally, the stability problem has been one of maintaining synchronous operation.Since power systems rely on synchronous machines for generation of electrical power, a necessary condition for satisfactory system operation is that all synchronous machines remain in synchronism or, colloquially “in step”.This asp ect of stability is influenced by the dynamics of generator rotor angles and power-angle relationships, and then referred to “ rotor angle stability ”译文:电力系统现代社会比以往任何时候更多地依赖于电力供应。
One operating system might be better suited to some computing tasks than others.To provide clues to their strengths and weaknesses,operating systems are informally categorized and characterized using one or more of the following terms:(1) A single-user operating system expects to deal with oneset of input devices -those that can be controlled by one user at a time.Operating systems for handheld computers and many personal computers fit into the single-user category.(2)A multiuser operating system is derigned to deal with input,output,and processing requests from many users-all atthe same time.One of its most difficult responsibilities is to schedule all of the processing requests that must be performed by a centralized computer-often a mainframe.(3)A network operating system(also referred to as a “server operating system”) provides communications and routing services that allow compoters to share data,programs,and peripheral devices.Novell Netware,for example,is almost always referred to as a network operating system。
第一章第一篇sectiongTwo variables u(t) and i(t) are the most basic concepts in an electric circuit, they characterize the various relationships in an electric circuitu(t)和i(t)这两个变量是电路中最基本的两个变量,它们刻划了电路的各种关系。
Charge and CurrentThe concept of electric charge is the underlying principle for explaining all electrical phenomena. Also, the most basic quantity in an electric circuit is the electric charge. Charge is an electrical property of the atomic particles of which matter consists, measured in coulombs (C).电荷和电流电荷的概念是用来解释所有电气现象的基本概念。
也即,电路中最基本的量是电荷。
电荷是构成物质的原子微粒的电气属性,它是以库仑为单位来度量的。
We know from elementary physics that all matter is made of fundamental building blocks known as atoms and that each atom consists of electrons, protons, and neutrons. We also know that the charge e on an electron is negative and equal in magnitude to 1.60210×10 19C, while a proton carries a positive charge of the same magnitude as the electron. The presence of equal numbers of protons and electrons leaves an atom neutrally charged.我们从基础物理得知一切物质是由被称为原子的基本构造部分组成的,并且每个原子是由电子,质子和中子组成的。
第一章第一篇sectiongTwovariables u(t)and i(t)arethemostbasicconceptsinanelectriccircuit,theych aracterizethevariousrelationshipsinanelectriccircuitu(t)和i(t)这两个变量是电路中最基本的两个变量,它们刻划了电路的各种关系。
ChargeandCurrent×10ed.于1.602100×10-12C,而质子所带的正电量在数值上与电子相等。
质子和电子数量相同使得原子呈现电中性。
Weconsidertheflowofelectriccharges.Auniquefeatureofelectricchargeorelect ricityisthefactthatitismobile;thatis,itcanbetransferredfromoneplacetoano ther,whereitcanbeconvertedtoanotherformofenergy让我们来考虑一下电荷的流动。
电荷或电的特性是其运动的特性,也就是,它可以从一个地方被移送到另一个地方,在此它可以被转换成另外一种形式的能量。
Whenaconductingwireisconnectedtoabattery(asourceofelectromotiveforce),th echargesarecompelledtomove;positivechargesmoveinonedirectionwhilenegativ echargesmoveintheoppositedirection.Thismotionofchargescreateselectriccur~上时(于是电流就是电荷的时率,它是以安培为单位来度量的。
从数学上来说,电流i、电荷q以及时间t之间的关系是:Thechargetransferredbetweentime t0and t isobtainedbyintegratingbothsidesofE q.(1-1).Weobtain从时间t0到时间t所移送的电荷可由方程(1-1)两边积分求得。
我们算得:Thewaywedefinecurrentas i inEq.(1-l)suggeststhatcurrentneednotbeaconstant-valuedfunction,chargecanvarywithtimeinseveralwaysthatmayberepresentedbyd ifferentkindsofmathematicalfunctions我们通过方程(1-1)定义电流的方式表明电流不必是一个恒值函数,电荷可以不同的方式随时间而变化,这些不同的方式可用各种数学函数表达出来。
成的。
电路中。
where w5~l827),whoinventedthefirstvoltaicbattery.Thus,Voltage(orpotentialdifferen ce)istheenergyrequiredtomoveaunitchargethroughanelement,measuredinvolts( V).式中w是单位为焦耳的能量而q是单位为库仑的电荷。
电压Uab是以伏特为单位来度量的,它是为了纪念意大利物理学家AlessandroAntonioVolta而命名的,这位意大利物理学家发明了首个伏达电池。
于是电压(或电压差)等于将单位电荷在元件中移动所需的能量,它是以伏特为单位来度量的。
Fig.l-2showsthevoltageacrossanelement(representedbyarectangularblock)con nectedtopoints a and b.Theplus(+)andminus(-)signsareusedtodefinereferencedi rectionorvoltagepolarity.The u abcanbeinterpretedintwoways:①point a isatapotentialof u abvoltshigherthanpointb;②eral图Uabanden们把这个关系式写成:Where p ispowerinwatts(W),w isenergyinjoules(J),and t istimeinseconds(s).From Eq.(1-1),Eq.(1-3),andEq.(1-5),itfollowsthat式中p是以瓦特为单位的功率,w 是以焦耳为单位的能量,t是以秒为单位的时间,从方程(1-1)、(1-3)和(1-5)可以推出Because u and i aregenerallyfunctionoftime,thepower p inEq.(1-6)isatime-varyin gquantityandiscalledtheinstantaneouspower.Thepowerabsorbedorsuppliedbyan elementistheproductofthevoltageacrosstheelementandthecurrentthroughit.If thepowerhasaplussign,powerisbeingdeliveredtoorabsorbedbytheelement.If,on theotherhand,thepowerhasaminussign,powerisbeingsuppliedbytheelement.Buthent i﹥﹤在我们确定功率符号时,电流的方向和电压的极性起着主要的作用,这就是我们在分析图1-3(a)所显示的电流i和电压u的关系时特别谨慎的重要原因。
为了使功率的符号为正,电压的极性和电流的方向必须与图1-3(a)所示的一致。
这种情况被称为无源符号惯例,对于无源符号惯例来说,电流流进电压的正极。
在这种情况下,p=ui或ui>0,表明元件是在吸收功率。
而如果p=-ui或ui<0,如图1-3(b)所示时,表明元件是在释放或提供功率。
Infact,thelawofconservationofenergymustbeobeyedinanyelectriccircuit.Fort hisreason,thealgebraicsumofpowerinacircuit,atanyinstantoftime,mustbezero 事实上,在任何电路中必须遵循能量守恒定律。
由于这个原因,任一电路中在任何瞬间功率的代数和必须等于零率等于有电阻、电容和电感器等。
最重要的有源元件是通常向与它们相连的电路释放能量的电压和电流源。
Independentsources Anidealindependentsourceisanactiveelementthatprovidesaspecifiedvoltageor currentthatiscompletelyindependentofothercircuitvariables.Anindependentvoltagesourceisatwo-terminalelement,suchasabatteryoragenera tor,whichmaintainsaspecifiedvoltagebetweenitsterminals.Thevoltageiscompl etelyindependentofthecurrentthroughtheelement.Thesymbolforavoltagesource having u voltsacrossitsterminalsisshowninFig.1-4(a).Thepolarityisasshown,i ndicatingthatterminal a is u voltsaboveterminal b.Thusif u>0,thenterminal a isatu>0在图1U1-4(a)或图1-4(b)WemightobserveatthispointthatthepolaritymarksonFig.1-4(b)areredundantsin cethepolaritycouldbedefinedbythepositionsofthelongerandshorterlines.我们可能已经注意到这一点,即图1-4(b)中的极性标号,是多余的因为我们可以根据长天线的位置符,确定电池极性Anindependentcurrentsourceisatwo-terminalelementthroughwhichaspecifiedcu rrentflows.Thecurrentiscompletelyindependentofthevoltageacrosstheelement .ThesymbolforanindependentcurrentsourceisshowninFig.1-5,where i isthespeci fiedcurrent.Thedirectionofthecurrentisindicatedbythearrow一个独立电流源是二端元件在两端之间特定的电流流过,该电流完全独立于元件两而电流算出。
1-6(bAnidealdependent(orcontrolled)sourceisanactiveelementinwhichthesourcequa ntityiscontrolledbyanothervoltageorcurrent. Dependentsourcesareusuallydesignatedbydiamond-shapedsymbols,asshowninFig .1-7Sincethecontrolofthedependentsourceisachievedbyavoltageorcurrentofso meotherelementinthecircuit,andthesourcecanbevoltageorcurrent,itfollowsthattherearefourpossibletypesofdependentsources,namely:(1)Avoltage-controlledvoltagesource(VCVS).(2)Acurrent-controlledvoltagesource(CCVS).(3)Avoltage-controlledcurrentsource(VCCS).(4)Acurrent-controlledcurrentsource(CCCS).ealcurrentsourcewillproducethenecessaryvoltagetoensurethestatedcurrentfl ow.Thusanidealsourcecouldintheorysupplyaninfiniteamountofenergy.Itshould alsobenotedthatnotonlydosourcessupplypowertoacircuit,buttheycanabsorbpow erfromacircuittoo.Foravoltagesource,weknowthevoltagebutnotthecurrentsupp liedordrawnbyit.Bythesametoken,weknowthecurrentsuppliedbyacurrentsourcebutnotthevoltageacrossit.应该注意的是:一个理想电压源(独立或受控)可向电路提供以保证其端电压为规定值所需的任意电流,而电流源可向电路提供以保证其电流为规定值所必须的电压。