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1、电流继电器电流继电器Protective Relaysn继电器是根据某种输入信号的变化，接通或断开控制电继电器是根据某种输入信号的变化，接通或断开控制电路，实现自动控制和保护电力装置的自动电器。路，实现自动控制和保护电力装置的自动电器。n分类：分类：n继电器的种类很多，按输入信号的性质分为：电压继电继电器的种类很多，按输入信号的性质分为：电压继电器、电流继电器、时间继电器、温度继电器、速度继电器、电流继电器、时间继电器、温度继电器、速度继电器、压力继电器等；器、压力继电器等；n按工作原理可分为：电磁式继电器、感应式继电器、电按工作原理可分为：电磁式继电器、感应式继电器、电动式继电器、热继电器和
2、电子式继电器等；动式继电器、热继电器和电子式继电器等；n按输出形式可分为：有触点和无触点两类，按用途可分按输出形式可分为：有触点和无触点两类，按用途可分为：控制用与保护用继电器等。为：控制用与保护用继电器等。n常用继电器：q电磁式继电器DL-10电磁型过电流继电器1线圈 2电磁铁 3钢舌片 4轴 5反作用弹簧 6轴承 7静触点 8动触点 9起动电流调节转杆 10标度盘（铭牌）原理：线圈通电后铁芯原理：线圈通电后铁芯被磁化产生足够的电磁被磁化产生足够的电磁力吸引衔铁并带动簧片，力吸引衔铁并带动簧片，使动触点和静触点闭合使动触点和静触点闭合或分开，当线圈断电后，或分开，当线圈断电后，电磁吸力消失，
3、动触点电磁吸力消失，动触点和静触点回到原来闭合和静触点回到原来闭合或断开状态，达到控制或断开状态，达到控制的目的。的目的。nhttp:/ 2铁心 3短路环 4铝盘 5钢片 6框架 7调节弹簧 8制动永久磁铁 9扇形齿轮 10涡杆 11扁杆 12继电器触头 13时间调节螺杆 14速断电流调节螺杆 15衔铁 16动作电流调节插销主要用于变压主要用于变压器及其他电气器及其他电气设备的过电流设备的过电流及短路保护。及短路保护。n继电器的工作原理是:当继电器的线圈通以交流电流时，则在铁芯的遮蔽与未遮蔽部分产生两个具有一定相位差的磁通。圆盘在此磁通的作用下，产生转矩。在20%-40%动作电流整定值下，圆盘
4、开始转动。此时由于扇齿与蜗杆没有咬合，故障电器触点不动作。当线圈中的电流增大至整定电流时，电磁力矩大于弹簧的反作用力矩。框架转动，使扇齿与蜗杆咬合，扇齿上升。在扇齿顶杆的推动下，使动铁动作，触点闭合。q电压继电器n输入量(激励量)是电压并当其达到规定的电压值时做出相应动作的一种继电器。n电磁型电压继电器有过电压继电器和欠电压继电器两种。其结构与电磁型电流继电器相同，但电压继电器一般是经过电压互感器接在电力网上，其动作行为取决于电网电压。q时间继电器n当加入(或去掉)输入的动作信号后，其输出电路需经过规定的准确时间才产生跳跃式变化(或触头动作)的一种继电器。n时间继电器应用钟表机构和电磁铁作用，
5、获得一定的动作时限。在继电保护中完成保护装置的计时功能。q中间继电器n用于增加控制电路中的信号数量或信号强度的一种继电器。用于增加控制电路中的信号数量或信号强度的一种继电器。辅助继电器。辅助继电器。n中间继电器的触头容量较大，触头数量较多，在继电保护接中间继电器的触头容量较大，触头数量较多，在继电保护接线中，当需要同时闭合或断开几条独立回路，或者要求比较线中，当需要同时闭合或断开几条独立回路，或者要求比较大的触点容量去断开或闭合大电流回路时，可以采用中间继大的触点容量去断开或闭合大电流回路时，可以采用中间继电器。中间继电器可以用来直接接通电器。中间继电器可以用来直接接通断路器断路器的跳闸回路。
6、的跳闸回路。q信号继电器n信号继电器用来标志保护装置的动作，并同时接通灯光和声信号继电器用来标志保护装置的动作，并同时接通灯光和声响信号回路。其机构与中间继电器相同，但多了信号牌和手响信号回路。其机构与中间继电器相同，但多了信号牌和手动复归旋钮。动复归旋钮。q差动继电器n差动继电器由位于系统中两个不同位置的电流互感器提供反差动继电器由位于系统中两个不同位置的电流互感器提供反馈信息。差动继电器对电流进行比较，如果存在不同则表示馈信息。差动继电器对电流进行比较，如果存在不同则表示受保护区域内有故障存在。此类继电器主要用于保护发电机受保护区域内有故障存在。此类继电器主要用于保护发电机线圈、变压器、一
7、段线路及母线设备。线圈、变压器、一段线路及母线设备。q温度继电器n主要测量电气设备的温度。主要测量电气设备的温度。New wordsn1.relayqn.驿马,接替,电工继电器qvt.(消息,货物等)分程传递,使接替,转播qvi.得到接替,转播nwork in by relays 轮班工作nnew relays of troops 新补充的部队nrelay station 中继站,转播站n2.energizeqvt.给加能量；激发；励磁n3.abnormalqadj.反常的,变态的nabnormal psychology变态心理学nAbnormallyqadv.nAbnormalismqn.变
8、态性,反常性n4.plungerq投入水中的人物,跳水者,潜水者q(枪炮等发火装置的)撞针杆;【机】柱塞,活塞;(电磁铁的)插棒式铁心;(波导管)短路器q投机者;冒险者;狂赌者;鲁莽的人n5.solenoidq【电】网络,网络管;螺线管,螺线管线圈,电磁线圈;电磁铁 n6.hingeq铰链;折合叶;活页;转轴q枢纽;门枢;节点,活动关节,关键;转折点nA door turns on its hinge.门依靠门枢而转动。qvi.靠铰链转动附着(on,upon);以看.而定;以.为转移(on,upon),取决于,关键在于nEverything hinges on how hard we work
9、.n一切取决于我们工作努力的程度。qvt.装上合叶;用铰链接合;使以.为转移依据nhinge onq取决于,随.而定,以.为转移noff the hingesq(门窗等)脱开铰链的q口脱节;损坏;混乱q口身体欠佳;精神失常;惊慌失措n8.inductionn9.diskn10.torquen11.rotorn13.instantaneousn12.inherentqadj.固有的,内在的,与生俱来的ninherent contradictions 内在矛盾ninherent laws 内在规律nbe inherent inq为.所固有,是.的固有性质;生来的nPolarity is inher
10、ent in a magnet.n极性是磁铁的固有性质。n14.impairqvt.损害,伤害;减少(量、价值、力等)nimpair ones health 损害某人健康n15.dragqv.拖,拖曳,缓慢而费力地行动qn.拖拉nmagnetic drag 磁阻npull为通用词。常伴有状语表示拖的方向qA small fishing-boat was carried miles out to sea by a powerful fish as it pulled on the line.q一条小渔般被一条力气强大的鱼拖着鱼线带数英里以外的海上去了。ndrag的含义是“慢慢地而沉重的拽”，而且
11、包含着被拖者进行着积极的或消极的阻抗或阻力qWhen he had killed the guard,the prisoner of war quickly dragged him into the bushes.q战俘杀死卫兵后，很快把他拖进矮树丛中。qBy this time,however,three men had come into the ring and they quickly dragged the drunk to safety.q不过，到这时候三个人已经走进了拳击场，把醉汗拖到了安全的地方。n16.inertiaq【物】惯性;惯量【医】惰性;无力q不活动;迟钝,缺乏活动性
12、nmoment of inertia转动惯量;惯性矩n17.ingeniousqadj.机灵的,有独创性的,精制的,具有创造才能nan ingenious author有创造力的作家nan ingenious device精巧的装置n18.incorporateqadj.合并的,结社的,一体化的qvt.合并,使组成公司,具体表现qvi.合并,混合,组成公司qvt.律结社,使成为法人组织nYour idea will be incorporated in the plan.n将把你的意见编入计划。nWhen his business became large,he incorporated it
13、.n在他的商店业务扩充之后,他把它组成公司。n19.sustainedqadj.持续的;不变的;不间断的;被支持的nmake sustained efforts 再接再励nsustained flight 稳定持久飞行;(火箭)巡航飞行nsustainqvt.支撑,撑住,维持,持续n20.crippleqn.跛子qv.削弱;使失去战斗力,损坏nbe a cripple for life 成终生残疾nThe ship was crippled in the storm.那船在暴风雨中受到严重损坏。nHe that lives with cripples learns to limp.近朱者赤,近
14、墨者黑。n21.staticq静态的：无动作的；静止的；静态的q【电学】静电的：静电的、与静电有关的或产生静电的nstatic induction 静电感应nDynamicqadj.动力的,动力学的,动态的 n22.insulationn23.surgeqn.巨涌,汹涌,澎湃qvi.汹涌,澎湃,振荡,滑脱,放松qvt.使汹涌奔腾,急放q【电】电涌,振荡na surge of joy.喜从天降nAnger surged(up)within him.n他胸中怒气汹涌。nlightning surge 雷电冲击波,雷涌,雷电冲击nsurgelessqadj.平稳的,平静的,无波涛的n24.loopq
15、n.环,线(绳)圈,弯曲部分,回路,回线,(铁路)让车道,(飞机)翻圈飞行qvt.使成环,以圈结,以环连结qvi.打环,翻筋斗qn.循环q【电学】闭合电路nknock for a loop/throw for a loopq使震惊,造成混乱;使激动q猛击;打昏;把.醉倒q给.极好的印象q使陷入突然的灾难或不幸non the loopq在匆匆旅行中Phrases and Expressionsn1.respond to 回报n2.the same is true for 同样符合于n3.assign to 指定，委派n4.drop out 派出n5.time delay 延时n6.instant
16、aneous operation 瞬时动作n7.sensing device 互感器n8.differential relay 差动保护Protective RelaysnA protective relay is a device that may be energized by a voltage signal,a current signal,or both.nWhen energized,it operates to indicate or isolate an abnormal operating condition（运行状态）.nBasically the protective r
17、elay consists of an operating element and a set of contacts.nThe operating element takes the signal from sensing devices（传感器）in the system,such as current or potential transformers(or both),performs a measuring operation,and responds to the results by causing the contacts to open or close.n When the
18、 relay operates,it may either actuate a signal or complete a circuit to trip a circuit breaker,which in turn isolates the section of the system that is in trouble.nOperating elements of protective relays are generally constructed in four basic types.These aren1.Plunger or solenoid typen2.Hinged arma
19、turen3.Induction diskn4.Induction cupnThe plunger and the hinged armature type work by magnetic attraction.In these the moving part,called the armature,is attracted into a coil or to the pole face of an electromagnet.This type of relay-operating element may be applied on either alternating-or direct
20、-current circuits.nThe induction-type relays are magnetic-induction types wherein torque is developed in a moving rotor in the same way that it is produced in an electric motor.These relays can only be used on alternating-current circuits.nThe plunger and hinged armature relays have no inherent time
21、 delay and so are used in applications where instantaneous operation is required.nThe air gap on the hinged armature type changes as the relay operates,which means that the force required to close it changes and the force to allow the armature to drop out（退出）again is reduced.nFor this reason,its mea
22、suring quality is impaired.The same is true for the plunger type but to a lesser degree.nThe induction disk type is used when time delay in relay operation is required.The time delay is caused by the addition of the permanent magnet.The disk rotates,causing an induction drag.nThe induction cup rotat
23、ing parts are of low inertia so this relay is capable of high-speed operation.It is used for functions requiring instantaneous response.nElements of the types described above and other ingenious operators are incorporated into the many types of protective relays available.All protective relays have
24、a separate device number assigned to them in the standard adopted for automatic switchgear by the American National Standards Institute(ANSI).uThe main power transformer must be protected from possible faults because loss of this piece of equipment,through damage from a sustained short circuit,would
25、 be as crippling to the system capability as loss of the generator.Transformers are static devices and have only alternating-current windings so the protection problem is less serious than for rotating equipment.There are two principle causes for insulation failures in transformers.They are(1)over-v
26、oltage resulting from lightning,switching surges,etc.,and(2)repeated overheating due to overloading or failure of the cooling system.nDifferential relaying is often used to protect large power transformers.In this particular case,the primary feeder to the primary winding（一次绕组）of the unit station ser
27、vice transformer is included in the zone of protection.The current transformers are all connected in a loop arrangement and normal currents will simply circulate.A fault anywhere within the zone of protection will cause a difference current to flow,energizing the relay.The lockout relay will be wire
28、d to operate when energized by the differential relay and to shut down the same circuit elements as those shut down for the generator.ExercisesnI.Translate the following expressions into Chinese or English.转动设备rotating equipment静态设备static device直流电流direct current circuit交流电流alternating current circu
29、it瞬时动作instantaneous operation测量动作measuring operation电流信号current signal电压信号voltage signal感应型继电器induction-type relay继电保护器the protective relay正常运行normal operation非正常运行abnormal operation铁路系统a railway system冷却系统a cooling system常设委员会a permanent committee永久磁铁a permanent magnet北极星the pole star极面the pole fac
30、e各种血型types of various blood磁感应型magnetic-induction typesnII.Fill in the following blanks with the words given.There are extra items.q1.Transmission lines are classified into two types:overhead line and underground _.(cable)q2.Natural science includes the broad fields of astronomy,biology,earth scienc
31、e,_ and physics.(chemistry)q3.Since the industrial revolution,mans demand for and consumption of energy has _ steadily.(increased)q4.To reduce the consumption of energy we must _ the wasteful burning of fossil fuels.(prevent)q5.The radioactive should be kept safe to _ the surrounding areas from bein
32、g polluted by radiation.(protect)chemistry prevent carry customers cable increasedprotect power electricity feeder rely on drop outq6.A laser beam traveling through an enclosed cube can _ as much information as 80 million TV channels.(carry)q7.Some scientists believe solar energy is one of the main
33、sources which can meet the worlds enormous need for _.(power)q8.The company provides services to over a million _ via 750 plus distribution feeder.(customers)q9.A substation is an assemblage of equipment for the purpose of switching or changing or regulating the voltage of _.(electricity)q10.If a co
34、mputer thinks,learns and creates,it will _ a program that endows it with these capacities.(rely on)chemistry prevent carry customers cable increasedprotect power electricity feeder rely on drop outnIII.Put the following sentences into English.q1.牛顿的运动定律适用于适用于地球上的一切东西。(apply to)qNewtons Laws of Motio
35、n apply to all things on the earth.q2.电磁波的传播速度和光速相同相同。(the same as)qElectromagnetic waves travel at the same speed as light.q3.激光只有一种颜色，而不像太阳光那样有多种颜色。(consists of)qLaser consists of only one color,and not of many colors like sunlight.q4.目前运行的最大发电机组容量容量为60万千瓦。(in capacity)qAt present the largest oper
36、ating generating unit is 600 MW in capacity.q5.前领导已派往派往一座新的热电厂主持工作。(assigned to)qThe former leader has been assigned to a new thermal power plant for work.Skill of translation:从句的译法n从句是相对于主句而言的，即它是从属于某一个主句，而不能单从句是相对于主句而言的，即它是从属于某一个主句，而不能单独作一个句子。在英语中，主要有三大从句，即独作一个句子。在英语中，主要有三大从句，即名词性从句名词性从句（包（包括主语从句，
37、宾语从句，表语从句，同位语从句）、括主语从句，宾语从句，表语从句，同位语从句）、形容词性从形容词性从句句（即定语从句）、（即定语从句）、副词性从句副词性从句（即状语从句（即状语从句,包括时间、条件、包括时间、条件、结果、目的、原因、让步、地点、方式等）。结果、目的、原因、让步、地点、方式等）。n定语从句的译法定语从句的译法一、合译法（一、合译法（.的）的）合译法一般适用于限定性定语从句和限定意义较强，且句子较短的非限定性定语从句。A car which is in motion has kinetic energy.正在开动的车子具有动能。He wrote a book,which is ab
38、out economics.他写了一本经济学方面的书。The negative smoke particles are then attracted to inside surface of the surrounding tube which is positive.带负电的烟粒子被吸向带负电的烟粒子被吸向带正电的带正电的周围管子的内侧面。周围管子的内侧面。q二、分译法q分译法一般适用于非限定性定语从句和某些句子较长的限定性定于从句。qIn power station,coal or oil is burned and changed into electricity,which is th
39、en sent over to homes and factories.q在发电站里，煤和油燃烧变成电，然后电沿导线输送到用户和工厂。qThe process by which energy is changed from one form into another is called the transformation of energy.q能量从一种形式变成另一种形式，这一过程称为能量转换。qThere are 107 known elements,most of which are metals.q已知元素有107种，其中大多数是金属。q三、译成状语从句qMan cant live o
40、n the moon,where there is no air and water.q人不能在月球上生存，因为那里没有空气和水。qElectronic computers,which have many advantages,cant carry out creative work and completely replace people.q尽管电子计算机有许多优点，但是它们不能进行创造性的工作，也不能代替人。qThe manufacture of this equipment is a very complex one,which took us a lot of time.q这种设备的
41、制造很复杂，以致花了我们很多时间。q四、特种定语从句的译法q特种定语从句主要指由which或as引导的非限制性定语从句，which 或as指代整个主句。由which引导的定语从句常译成“这”，有时也可以译成“从而”、“因而”。由as引导的定语从句常译成“这”、“如”、“像”等词。qLight travels in straight lines,which explains why shadows are formed when it goes past an object.q光以直线传播，这说明光经过物体时形成阴影的原因。qTo find the pressure we divide the
42、force by the area on which it presses,which gives us the force per unit area.q要求压强，则把力除以它所作用的面积，从而得出单位面积上的力。qMetals have many good properties,as has been stated before.q金属具有许多良好的性能，这在前面已经讲了。状语从句的译法n将状语从句译成汉语时，应按照汉语的语序习惯来译。n一、前置译法nWater contracts when it is cooled.n水冷却时要收缩。（时间状语）nA body accelerates w
43、hen it is falling.n物体下落时有加速度。（时间状语）qWherever there is matter,there is motion.q哪里有物质，哪里就有运动。（地点状语）qAn object at rest will not move unless a force is exerted on it.q如果不受外力的作用，静止的物体就不会移动。（条件状语）qWe must study and work hard so that we can speed up the four modernizations of our country.q为了加快我国的四个现代化建设，我们
44、一定要努力学习和工作。（目的状语）q二、后置译法qThe steel is heated until it becomes red.q将钢加热到发红。（时间状语）qMost parts of that machine will be made of plastic instead of metal so that its weight may be greatly decreased.q那台机器的大部分零件将不用金属而用塑料制成，为的是大大减轻其重量。（目的状语）qTransistors are small in size and light in weight,so they find wi
45、de application in the radio industry.q晶体管尺寸小、重量轻，所以在无线电工业中得到广泛应用。（结果状语）qElectricity flows through a wire just as water flows throw a pipe.q电流通过导体，正像水流过管子一样。（方式状语）n三、译成分句nThe transistor radio is so small that you can carry it in your pocket.n这台晶体管收音机很小，你可以把它放在衣袋里。nThey set him free when his ransom ha
46、d not yet been paid.n他还没有交赎金，他们就把他释放了。nHe shouted as he ran.n他一边跑，一边喊。nBecause he was convinced of the accuracy of this fact,he stuck to his opinion.n他深信这件事正确可靠，因此坚持己见。n 课堂练习1：n The main constituents of an ac power system are:generators,transmission(subtransmission),and distribution lines,and loads,
47、with their related auxiliary support and protection equipment.The generators are rotation synchronous machines.The transmission,subtransmission,and distribution lines are essentially distributed parameter(分布参数）,dominantly（主要地）（主要地）reactive（感性）networks designed to operate at high,medium,and low,alter
48、nating voltages,respectively.The loads may be synchronous,non-synchronous,and passive（无源的）,consuming in general both real and reactive power（无功功率）.课堂练习2：n翻译：n1.Magnetic fields are produced by electric currents,which is passed through suitable coils,setting up a strong magnetic field across the space between the switches contacts as they are opened.n2.The force arm is defined as the perpendicular distance from the axis of rotation to the line of action of the force.n1.knife switch n2.air-break switch n3.oil switch n4.SF6 breaker switchn5.vacuum switchn6.rated current 结束结束