电力专业英语第七讲

1、山东交通学院电气系张建军 词汇intercept ntsept n. 截流 截击; 拦截，拦住; 截球; 拦阻;intercept valve 截流阀，再热调节汽门divert dav:t v. 转换 ;娱乐; 转移注意力steam chamber 蒸汽养护室crossover krsv(r)n. 转换器;天桥; 生 （杂色体的） 杂交，交换; 铁路 岔道，转线路; （交搭胸前的）女围巾;megawatt n. 兆瓦MWsynchronous skrnsa. 同步的，同时的;同时存在发生的implement mplmentv. 完成，补充;实施，执行; 使生效，实现; 落实; （政策） 把填满

2、;supplement splmntv. 补充，添加;增补; 补充物; 增刊，副刊;supplementary a. 补充的armature :mt(r) n. 电枢;衔铁; 转子; 支架;torque t:k n. 转矩; 扭转力; damp v. 阻尼，减振bond n. 联接deceleration n. 减速rectify rektfa v. 整流改正，校正; 化 精馏; thyristor arst n. 晶闸管，硅可控整流器 课文内容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基本设备the turbine and governor with a speed feedback 带有速度反馈的汽轮机和发电机 exciter励磁器; 激励器; 励磁机 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蒸汽中能量与机械能的转换thermodynamic process热动过程Shaft转轴turbine blades汽轮机叶片 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 控制阀; 调节阀; intercept valves 截流阀，再热调节汽门divert转换divert the steam from the high-pressure tu

7、rbine directly to the steam condenser引导蒸汽由高压汽轮机直接进入凝汽器 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一个延时Reheater再热器crossover n. 转换器 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调节器;调速器 usually the synchronous speed of the turbine-generator set 通常是配套汽轮机与发电机的同步转速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 区域或地区电力系统主电站的调速器in a large interconnected electric power system在一个大的电网系统the scheduled electric power inter

12、change计划的电能交换local load variations当地负荷的变化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实现调速器的辅助控制improve the stability of an electric power system改善电力系统的稳定性 the mechanical-hydraulic governor 机械液压调速器 the electric-hydraulic governor电动液压调速器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同步发电机同步发电机The mechanical-electric energy conversion机械能和电能的转换in the form of a force or a torque以力或力矩的形式 with respect to关于；相对于； 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有一点必须要指出的是an electric torque一个电磁转矩opposite to the mechanical torque of the prime mover 与原动机的机械转矩相反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 大规模发电one dc-excited field on the rotor转子中的直流励磁场with a field winding 带有励磁线圈的the other ac-excited（field ) on the stator定子中的交流励磁磁场with the three-phase armature winding带有三相电枢绕组的 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, 与其它相相差120度电角度and each phase current with a 120 time phase difference并且每相电流与其它相有120度的时间相位差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三相绕组的旋转磁场with three-phase excitation带有三相励磁的For the moment目前；眼下；现在the difference between the two fields should be noted.需要强调这两个磁场的差别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三相交流磁场的转速dictate dktet 口述; 命令，指示; 使听写; 控制，支配; and the field appears in and around the air gap of the machine instantly并且这个磁场会立即出现在气隙内部和外

22、周nature of the electromagnetic field电磁场的特性On 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被旋转系统的惯性和阻尼影响Only in the steady state只有在稳态there be neither acceleration nor deceleration of the rotating system旋转系统既没有加速也没有减速 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在这种情况下will be moving together s

25、ynchronously将在一起同步旋转with the N poles of the ac field facing the S poles of the dc field交流磁场的N极面对着直流磁场的S极across the air gap of the machine隔着发电机的空气隙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当电力系统出现干扰the input-output energy balance is upset输入与输出间的能量平衡就被打破了will be shaken（状态）被动摇；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励磁机励磁机the commutator-type rotating exciter换向器类型的旋转励磁机换向器类型的旋转励磁机static exciters静态励磁机励磁机thyristors晶闸管，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