電力專業(yè)英語第七講

1、山東交通學(xué)院電氣系張建軍 詞匯intercept ntsept n. 截流 截?fù)? 攔截，攔住; 截球; 攔阻;intercept valve 截流閥，再熱調(diào)節(jié)汽門divert dav:t v. 轉(zhuǎn)換 ;娛樂; 轉(zhuǎn)移注意力steam chamber 蒸汽養(yǎng)護(hù)室crossover krsv(r)n. 轉(zhuǎn)換器;天橋; 生 （雜色體的） 雜交，交換; 鐵路 岔道，轉(zhuǎn)線路; （交搭胸前的）女圍巾;megawatt n. 兆瓦M(jìn)Wsynchronous skrnsa. 同步的，同時(shí)的;同時(shí)存在發(fā)生的implement mplmentv. 完成，補(bǔ)充;實(shí)施，執(zhí)行; 使生效，實(shí)現(xiàn); 落實(shí); （政策） 把填滿

2、;supplement splmntv. 補(bǔ)充，添加;增補(bǔ); 補(bǔ)充物; 增刊，副刊;supplementary a. 補(bǔ)充的armature :mt(r) n. 電樞;銜鐵; 轉(zhuǎn)子; 支架;torque t:k n. 轉(zhuǎn)矩; 扭轉(zhuǎn)力; damp v. 阻尼，減振bond n. 聯(lián)接deceleration n. 減速rectify rektfa v. 整流改正，校正; 化 精餾; thyristor arst n. 晶閘管，硅可控整流器 課文內(nèi)容Basic Components of an Electric Power PlantThe basic components of an elect

3、ric power plant may be schematically shown as in Fig.4-1. In the figure, the turbine and governor with a speed feedback are shown on the left, the generator SG, exciter EX, and voltage regulator VR with a voltage feedback Vt are shown in the middle, and the transformer and transmission line are show

4、n on the right.The basic components基本設(shè)備the turbine and governor with a speed feedback 帶有速度反饋的汽輪機(jī)和發(fā)電機(jī) exciter勵(lì)磁器; 激勵(lì)器; 勵(lì)磁機(jī) The Steam TurbineThe steam-mechanical energy conversion is a thermodynamic process by which the steam is expanded through the high-, medium-, and low-pressure turbines, normally

5、all on one shaft. High-pressure and high-temperature steam energy from a boiler is converted into mechanical energy through the turbine blades, and transmitted to the shaft.The steam-mechanical energy conversion蒸汽中能量與機(jī)械能的轉(zhuǎn)換thermodynamic process熱動(dòng)過程Shaft轉(zhuǎn)軸turbine blades汽輪機(jī)葉片 There are other important

6、 parts of the turbine: the control valves, which control the steam input; the intercept valves, which can be used to divert the steam from the high-pressure turbine directly to the steam condenser; control valves 控制閥; 調(diào)節(jié)閥; intercept valves 截流閥，再熱調(diào)節(jié)汽門divert轉(zhuǎn)換divert the steam from the high-pressure tu

7、rbine directly to the steam condenser引導(dǎo)蒸汽由高壓汽輪機(jī)直接進(jìn)入凝汽器 the steam chamber in front of the high-pressure turbine, which causes a time delay of the steam flow; the reheater between the high-and medium-pressure turbines, which causes another time delay; and the crossover connection between the medium-an

8、d low-pressure turbines, which causes still another time delay of the steam flow. Many other types of steam turbines are in use.the steam chamber蒸汽室a time delay一個(gè)延時(shí)Reheater再熱器crossover n. 轉(zhuǎn)換器 The GovernorThe function of a governor of an electric power plant is to maintain a constant speed, usually t

9、he synchronous speed of the turbine-generator set. A speed drop of the set due to an increase of electric power output will send the speed signal to the governor to increase the mechanical power input to the turbine(s), and a speed rise to decrease the mechanical input, maintaining a constant speed.

10、Governor調(diào)節(jié)器;調(diào)速器 usually the synchronous speed of the turbine-generator set 通常是配套汽輪機(jī)與發(fā)電機(jī)的同步轉(zhuǎn)速The governor of the major plant of a power area or subsystem is also given the function of power and frequency control of the area in a large interconnected electric power system. The governor responds not on

11、ly to the scheduled electric power interchange among areas, but also to the change in system frequency due to local load variations. The governor of the major plant of a power area or subsystem 區(qū)域或地區(qū)電力系統(tǒng)主電站的調(diào)速器in a large interconnected electric power system在一個(gè)大的電網(wǎng)系統(tǒng)the scheduled electric power inter

12、change計(jì)劃的電能交換local load variations當(dāng)?shù)刎?fù)荷的變化Another use of the governor is to implement a supplementary governor control to improve the stability of an electric power system.There are two types of governors for both steam power and hydropower plants: the mechanical-hydraulic governor and the electric-h

13、ydraulic governor. implement a supplementary governor control實(shí)現(xiàn)調(diào)速器的輔助控制improve the stability of an electric power system改善電力系統(tǒng)的穩(wěn)定性 the mechanical-hydraulic governor 機(jī)械液壓調(diào)速器 the electric-hydraulic governor電動(dòng)液壓調(diào)速器The Synchronous GeneratorThe mechanical-electric energy conversion takes place in an elec

14、tric generator, usually of the three-phase synchronous type, and is based on Faradays induction law. The essential components are (1) an armature winding, (2) a magnetic field, and (3) a mechanical energy input, in the form of a force or a torque, which causes a relative motion of the armature windi

15、ng with respect to the field. The Synchronous Generator同步發(fā)電機(jī)同步發(fā)電機(jī)The mechanical-electric energy conversion機(jī)械能和電能的轉(zhuǎn)換in the form of a force or a torque以力或力矩的形式 with respect to關(guān)于；相對(duì)于； One must note that whenever there is a voltage induced in the generator armature winding due to its relative motion wit

16、h respect to the magnetic field, there is also an electric torque opposite to the mechanical torque of the prime mover when the generator has a load. One must note有一點(diǎn)必須要指出的是an electric torque一個(gè)電磁轉(zhuǎn)矩opposite to the mechanical torque of the prime mover 與原動(dòng)機(jī)的機(jī)械轉(zhuǎn)矩相反The three-phase synchronous generator u

17、sed for large-scale electric energy generation has two synchronously rotating fields: one dc-excited field on the rotor with a field winding mechanically rotated normally at the synchronous speed and the other ac-excited on the stator with the three-phase armature winding,large-scale electric energy

18、 generation 大規(guī)模發(fā)電one dc-excited field on the rotor轉(zhuǎn)子中的直流勵(lì)磁場(chǎng)with a field winding 帶有勵(lì)磁線圈的the other ac-excited（field ) on the stator定子中的交流勵(lì)磁磁場(chǎng)with the three-phase armature winding帶有三相電樞繞組的 each phase winding 120 apart from the others electrically, and each phase current with a 120 time phase difference

19、 with respect to the others. 120 apart from the others electrically, 與其它相相差120度電角度and each phase current with a 120 time phase difference并且每相電流與其它相有120度的時(shí)間相位差The rotating field of the three-phase winding with three-phase excitation will be analyzed later. For the moment, the difference between the t

20、wo fields should be noted. The rotating field of the three-phase winding三相繞組的旋轉(zhuǎn)磁場(chǎng)with three-phase excitation帶有三相勵(lì)磁的For the moment目前；眼下；現(xiàn)在the difference between the two fields should be noted.需要強(qiáng)調(diào)這兩個(gè)磁場(chǎng)的差別The speed of the three-phase ac field on the stator is completely dictated by the system frequenc

21、y, and the field appears in and around the air gap of the machine instantly because of the nature of the electromagnetic field.The speed of the three-phase ac field三相交流磁場(chǎng)的轉(zhuǎn)速dictate dktet 口述; 命令，指示; 使聽寫; 控制，支配; and the field appears in and around the air gap of the machine instantly并且這個(gè)磁場(chǎng)會(huì)立即出現(xiàn)在氣隙內(nèi)部和外

22、周nature of the electromagnetic field電磁場(chǎng)的特性O(shè)n the other hand, the speed and hence the dc field of the rotor are affected by the inertia and damping of the rotating system. Only in the steady state, when the mechanical energy input and the electric energy output plus the system losses are in complete

23、balance, will there be neither acceleration nor deceleration of the rotating system.and hence因此; are affected by the inertia and damping of the rotating system被旋轉(zhuǎn)系統(tǒng)的慣性和阻尼影響Only in the steady state只有在穩(wěn)態(tài)there be neither acceleration nor deceleration of the rotating system旋轉(zhuǎn)系統(tǒng)既沒有加速也沒有減速 In such a case,

24、 the two rotating fields, one dc and one ac, will be moving together synchronously, with the N poles of the ac field facing the S poles of the dc field, and the S poles of the ac field facing the N poles of the dc field across the air gap of the machine. In such a case在這種情況下will be moving together s

25、ynchronously將在一起同步旋轉(zhuǎn)with the N poles of the ac field facing the S poles of the dc field交流磁場(chǎng)的N極面對(duì)著直流磁場(chǎng)的S極across the air gap of the machine隔著發(fā)電機(jī)的空氣隙However, when a disturbance occurs to the system and the input-output energy balance is upset, the N-to-S and S-to-N bonds will be shaken, causing a possi

26、ble stability problem.when a disturbance occurs to the system當(dāng)電力系統(tǒng)出現(xiàn)干擾the input-output energy balance is upset輸入與輸出間的能量平衡就被打破了will be shaken（狀態(tài)）被動(dòng)搖；The Exciter and Voltage RegulatorFor years the dc excitation of a synchronous machine field winding has been provided by the commutator-type rotating ex

27、citer. However, static exciters using thyristors and other devices are now available, which respond much more rapidly than the commutator type.The Exciter勵(lì)磁機(jī)勵(lì)磁機(jī)the commutator-type rotating exciter換向器類型的旋轉(zhuǎn)勵(lì)磁機(jī)換向器類型的旋轉(zhuǎn)勵(lì)磁機(jī)static exciters靜態(tài)勵(lì)磁機(jī)勵(lì)磁機(jī)thyristors晶閘管，硅可控整流器A rotating exciter and voltage regulator system is shown in Fig. 4.2.The ac terminal voltage of the synchronous generator SG is sensed by a potential transformer PT, rectified and filtered, and then compared with a voltage reference VREF to obtain the vol