自动化专业英语教程王宏文第2版英译汉.docx

1、自动化专业英语教程王宏文第2版英译汉PART 1电路和电子工程基础 A 电路1In the case of a resistor, the voltage- current relationship is given by Ohm s law, which states that the voltage across the resistor is equal to the current through the resistor multiplied by the value of the resistance. 就电阻来说，电压电流的关系由欧姆定律决定。欧姆定律指出：电阻两端的电压等于电阻

2、上流过的电流乘以电阻值。2It may be that the inductor voltage rather than the current is the variable of interest in the circuit. 或许在电路中，人们感兴趣的变量是电感电压而不是电感电流。B 三相电路1Viewed in this light, it will be found that the analysis of three-phase circuits is little more difficult than that of single-phase circuits. 这样看来，三

3、相电路的分析比单相电路的分析难不了多少。2At unity power factor ，the power in a single-phase circuit is zero twice each cycle 在功率因数为 1 时，单相电路里的功率值每个周波有两次为零。3It should be noted that if the polarity of point A with respect to N ( ) is assumed for thepositive half-cycle, out of phase with, . 量图中时就应该画得同then when used in the

4、 same phasor diagram should be drawn opposite to, or 180应该注意，如果把 A点相对于 N的极性（ ）定为正半周，那么 在用于同一相相反，即相位差为 180 。A 运算放大器1One problem with electronic devices corresponding to the generalized amplifiers is that the gains,AU or AI, depend upon internal properties of the two-port system. 对应于像广义放大器这样的电子装置，一个问题

5、就是增益 AU 或者 AI ，它们取决于两输入端系统的内部特性。2This is one of the key features of Op-Amp design the action of the circuit on signals depends only upon the external elements which can be easily varied by the designer and which do not depend upon the detailed character of the Op-Amp itself. 这是运算放大器设计的重要特征之一在信号作用下，电

6、路的动作 仅取决于能够容易被设计者改变的外部元件，而不取决于运算放大器本身的细节特性。B 晶体管1Put very simply a semiconductor material is one which can be “doped” to produce a predominanceof electrons or mobile negative charges (N- type); or “holes ” or positive charges (P -type). 简单地说，半导体是这样一种物质，它能够通过“掺杂”来产生多余的电子，又称自由电子( N型)；或者产生“空穴” ，又称 正电子(

7、 P型)。2TO1 is the original transistor shape a cylindrical “can” with the three leads emerging in triangularpattern from the bottom. Looking at the base, the upper lead in the “triangle ” is the base, the oneto the right (marked by a color spot) the collector and the one to the left the emitter.TO1 是最

8、早的一种晶体管形状即一个带有三个引脚的圆柱体“外罩” ，这三个引脚在底部形成三角状。首先要注意的是， “三 角形”上面的引脚是基极，其右面的引脚(由一个彩色点标出)为集电极，其左面的引脚为发射极。A 逻辑变量与触发器1We shall now briefly discuss the relevance of such terminology, and in so doing we shall bring out the special aptness of the designations “true ” and “false ” to identify the possible values

9、 of avariable. 现在我们将简要地讨论一下这些术语之间的关联，并在此过程中阐明用标示“真”和“假”来识别一个 变量的可能值的特殊用途。2Just as other algebras deal with variables which have a numerical significance, Boolean algebra deals with propositions and is an effective tool for analyzing the relationships between propositions which allow only two mutuall

10、y exclusive alternatives. 和其他处理有数字意义的变量的代数一样，布尔代数处理的是命题，而且布尔代数对于分析仅有两个互反变量命题之间的关系是一种有效的工具。3There is a generally prevailing attitude in digital systems to view logic 0 as a basic, undisturbed, unperturbed, quiescent state and to view the logic 1 state as the excited, active, effective state, i.e., th

11、e state arrived at “after something has happened. ”在数字系统中，普遍的观点是把逻辑 0 看成一个基本的、无干扰的、稳定的、静止的状态，把逻辑 1 看成一个激励的、活跃的、有效的状态，也就是说，这种状态是发 生在“某种操作动作之后” 。B 二进制数字系统1Such devices operate well in a two-state or binary system, using conduction and cutoff as the operating states, and as a result the binary number s

12、ystem is generally employed in internal operations in digital computers. 将导通和关断作为工作状态，这样的装置可以在两态即二进制系统中运行，因此数字计算机中的内部操 作一般采用二进制系统。2Given the basic idea of a chain of positive and negative, or positive and zero, or zero and negative pulses as representing binary 1s and 0s, there are many possible cod

13、es in which the pulses might be transmitted. 给出一串正脉冲和负脉冲，或正脉冲和零，或者零和负脉冲来表示二进制的 1 及 0 时，就会有许多这 些脉冲可以传递的码。A 功率半导体器件1Power diodes provide uncontrolled rectification of power and are used in applications such aselectroplating, anodizing, battery charging, welding, power supplies (DCand AC), and variable

14、-frequency drives. 电力二极管提供不可控的整流电源，这些电源有很广的应用，如：电镀、电极氧化、电池充电、焊接、交 直流电源和变频驱动。2A gate turn-off thyristor (GTO), as the name indicates, is basically a thyristor-type device thatcan be turned on by a small positive gate current pulse, but in addition ， has the capability of beingturned off by a negative

15、 gate current pulse 门极可关断晶闸管，顾名思义，是一种晶闸管类型的器件。同 其他晶闸管一样，它可以由一个小的正门极电流脉冲触发，但除此之外，它还能被负门极电流脉冲关断。3Such a gate current pulse of very short duration and very large di/dt has small energy content andcan be supplied by multiple MOSFETs in parallel with ultra-low leakage inductance in the drive circuit.这样一个

16、持续时间非常短、 di/dt 非常大、 能量又较小的门极电流脉冲可以由多个并联的 MOSFET来提供， 并且驱动电路中的漏感要特别低。B 电力电子变换器1The efficiency of the rectifiers is very high, typically in the vicinity of 98%, because device由于器件开通时损耗低，且其开关损source by connection a large inductance 通过串联大电感，可变电conduction loss is low and switching loss is practically negl

17、igible. 耗几乎可忽略不计，故该类整流器的效率很高，典型值约为 98。2A variable voltage source can be converted to a variable current in series and controlling the voltage within a feedback current control loop. 压源可以在电流反馈控制回路的控制下转换为可变电流源。A 直流电机分类1due to its basic circuit arrangement and physicalEach of these motors has different

18、 characteristics properties. 每种类型的电动机由于其基本电路的不同而具有不同的特征和物理特性。2The only difference, in most cases, is that the generator acts as a voltage source while the motor functions as a mechanical power conversion device. 很多情况下，二者的唯一区别在于发电机常作为电压源， 而电动机常作为机械能转换装置。3A decrease in field current reduces the streng

19、th of the electromagnetic field. When the field fluxis decreased, the armature will rotate faster, due to reduced magnetic-field interaction. 励磁电流的减小会使磁场减弱。当磁通减少时，转子会由于与减弱的磁场相互作用而加速旋转。B 直流传动的闭环控制1Any positive speed error, caused by either an increase in the speed command or an increase in the load t

20、orque, produces a higher current reference Ia*. 由速度给定或负载转矩的增加所引起的任何正的速度 偏差，都会产生更大的参考电流值 Ia* 。2The speed error is corrected at the maximump ermissible armature current until the speed error becomes small and the current limiter comes out of saturation. 在最大允许电枢 I 下纠正速度偏差，直到速度偏差减 小且限流装置退出饱和状态。A 交流机1Neg

21、lecting the effect of slots and space harmonics due to non-ideal winding distribution, it canbe shown that a sinusoidal three-phase balanced power supply in the three-phase stator winding createsa synchronously rotating magnetic field. 如果忽略槽和由于非理想分布的绕组产生的空间谐波的影响，可以证 明，在三相定子绕组中能以三相对称电源建立一个同步旋转的旋转磁场。2

22、The rotor winding will be subjected to a sweeping magnetic field, and have inducing current in the short-circuited rotor. 转子绕组切割磁场，就会在短路的转子中产生感应电流。3This is in contrast to a machine with a cylindrical rotor structure having a uniform air gap （suchas an induction motor）, defined as a nonsalient pole m

23、achine. 与其 （ 凸极式同步机 ） 对应的另一种电机是有均匀气隙的圆柱体形转子结构的电机 （ 与异步机相似 ） ，定义为隐极式同步电机。4For example, the stator-pole pair A-A is energized when the rotor pole-pair a-a approaches it to produce the torque by magnetic pull, but is de-energized when pole alignment occurs. 例如，当转子极对a-a 接近定子极对 A-A 时，定子极对 A-A 被通电，通过磁拉力产生

24、转矩，当两个极对重合时，定子极对 A-A 断电。 B 感应电机传动装置1However, as the frequency is increased, the machine airgap flux falls causing low developed torque capability. 然而随着频率增加，电机的气隙磁通下降，导致产生的转矩降低。2In a well-designed PWMd rive, the commutation frequency should be increased as permitted by the devices so as to obtain a g

25、ood balance between the increase of inverter loss and decrease of machine loss. 在设计完善的 PWM传动系统中，应在器件允许的条件下增加换相频率，以便在逆变器损耗的增加和电机损耗的降低之 间找到一个合适的平衡点。A 电力系统1In cities and other areas where open lines create a safety hazard or are considered unattractive, insulated underground cables are used for distrib

26、ution. 在城市和其它地区，明线存在安全隐患或者被认为影响美观，所以使用绝缘地下电缆进行配电。2Each utility that agrees to share gains an increased reserve capacity, use of larger, more efficient generators, and the ability to respond to local power failures by obtaining energy from a linking grid. 同意共享的每个电力企业可以获得不断增加的储备功率，使用更大、效率更高的发电机，从电网中获取

27、电能以应对 局部电力故障。3Inductance and capacitance react with a tendency to nullify one another. 电感和电容的作用能相互抵消。B 电力系统自动化1Metering values such as demand and peak are saved within the meter to create historical information about the activity of the power system. 测量值，如需求量和峰值，可以保存在仪表中，用于创建电力系统运行的历史信息。2Substation

28、integration refers to combining data from the IED s local to a substation so that thereis a single point of contact in the substation for all of the I&C data. 变电站集成指的是将局部和整个变电站的 IED 数据进行组合，于是对于变电站内所有 I&C 数据，只有一个单联系点。3The communications industry uses the term client/server for a device that acts as a

29、 master, or client, retrieving data from some devices and then acts as a slave, or server, sending this data to other devices. 通信行业对设备使用术语客户 / 服务器， 该设备作为主设备或客户从其它设备得到数据，然后作为从设备或服务器 向其它设备发送数据。PART 2 控制理论 A 控制的世界1The reaction time of a human pilot is too slow to enable him or her to fly an aircraft wi

30、th a lightly damped Dutch roll mode without a yaw damper system. 飞行员的反应速度太慢，如果不附加阻尼偏航系统，飞行员就无法通过轻微阻尼的侧倾转向方式来驾驶飞机。2Since the output is fed back in a functional form determined by the nature of the feedback elements and then subtracted from the input 因为输出会以由反馈部件特性决定的函数形式反馈回来，然后从输入中减去B 传递函数和拉普拉斯变换1The

31、designer quickly becomes adept in relating changes in the Laplace domain to behavior in the time domain without actually having to solve the system equations. 设计人员很快就会熟练地把拉普拉斯域的变化与时域状态联系起来，而不需真地解系统方程（时域） 。A 稳定性和时域响应1The table is continued horizontally and vertically until only zeros are obtained. 这张

32、表向水平（向右）垂直（向下）方向延伸，直到得到的都是零为止。B 稳态1the principle of superposition holds, 叠加原理成立，2 , thus eliminating the velocity error, and by being introduced ahead of the point of entry of thedisturbance into the system, eliminates the steady-state error resulting from a step in the dist urbance. ，这样通过在系统扰动进入点之前引入（积分环节） ，可消除由扰动输入中的阶跃（成分）导致 的稳态误差。A 根轨迹1 as any single parameter, such