自动化专业英语考试整理版

精品文档 1欢迎下载 翻译 P 1 The voltage across a pure inductor is defined by Faraday law which states that the voltage across the inductor is proportional to the rate of change with time of the current through the inductor thus we have U Ldi dt 纯电感电压由法拉第定律定义 法拉第定律指出 电感两端的电压 正比于流过电感的电流随时间的变化率 因此可得到 U Ldi dt 式 中 di dt 电流变化率 安培 秒 L 感应系数 享利 P 3 A three phase electric circuit is energized by three alternating emfs of the same frequency and differing in time phase by 120 electrical degrees 三相电压的产生三相电路可由三个频率相同在时间相位上相差 120 电角度的电动势供电 P 9 One problem with electronic devices corresponding to the generalized amplifiers is that the gains AU or AI depend upon internal properties of two port system This makes design difficult since these parameters usually vary from device to device as well as temperature 运算放大器像广义放大器这样的电子器件存在的一个问题就是它们 精品文档 2欢迎下载 的增益 AU 或 AI 取决于双端口系统 m b RI Ro 等 的内部特性 器件之间参数的分散性和温度漂移给设计工作增加了难度 P 31 However the disadvantage is that they generate harmonics in the utility system creating a power quality problem for other consumers Besides thyristor converters constitute a low lagging power factor load on tha utility system 但是 它们的缺点是在电力系统中产生谐波 对其他用户产生供电 质量问题 此外 晶闸管变换器给电力系统提供了一个滞后的低功 率因数负载 P 32 Inverter is a device which receives DC voltage at one side and converts it to AC voltage on the other side 逆变器是从一侧接受直流电压 在另一侧将其转换成交流电压的装 置 Inverter can be classified voltage fed inverter and current fed inverter 逆变器可分成电压源型和电流源型两种 P 36 The permanent magnet motor has several advantages over convertional types of DC motors One advantage is reduced operational cost The speed characteristics of the 精品文档 3欢迎下载 permanent magnet motor are similar to those of the shunt wound DC motor The direction fo rotation of a permanent magnet moror can be reversed by reversing the twopower lines 永磁电机相对于常规直流电机有几个优点 优点之一是减少了运行 损耗 永磁电机的转速特性类似于并励式直流电机的转速特性 永 磁电机的旋转方向可通过将电源线反接来实现 P40 A signal proportional to the motor speed is obtained from the speed sensor The speed sensor output is filtered to remove the AC ripple and compared with the speed reference The speed error is processed through a speed controller The output of the speed controller UC adjusts the rectifier firing angle A to make the actual speed close to the reference speed 正比于电机速度的信号可从速度传感器获得 速度传感器的输出滤 除交流波 并与速度参考值比较 速度误差被速度控制器处理 速 度控制器的输出 uc 调整整流器的触发角 以使实际的速度接近 于参考速度 P 45 In a wound rotor machine the rotor wingding si similar to that of the stator but in a cage machine the rotor has a 精品文档 4欢迎下载 squirrel cage like structure with shorted end rings 对绕线式转子电机而言 转子绕组与定子绕组类似 但鼠笼式电机 的转子具有鼠笼状结构 并且有两个短路环 With the system transfer funcion known the Routh Hurwitz criterion will Tell us whether or not a system is stable If it is stable the steady state accuracy can be determined for various types of inputs 如果已知系统的传递函数 劳斯 胡尔维茨判据会告诉我们系统是否 稳定 如果系统稳定 可以确定各种类型输入时系统的稳态精度 P 87 There are as many as locus branches as there open loop poles A branch srtarts for K 0 at each open loop pole As K is increased the closed loop pole positions trace out loci which end for K at the open loop zeros 根轨迹的分支数等于开环极点数 当 K 0 时 分支起始于每一个开 环极点 随着 K 值的增加 闭环极点位置绘出根轨迹 当 K 时 根轨迹终止于开环零点 P 107 The transition from simple approximate modles which are easy to work with to more realistic models produces two effects First a larger number of variables must be 精品文档 5欢迎下载 included in the model Second a more realistic model is more likely to contain nonlinearities and time varying parameters 从易于处理的简单近似模型到实际一些的模型的转换产生了两种作 用 存在着两个方面的问题 第一 大量的变量必须包含在模型中 第二 更实际的模型更容易包含非线性和时变参数 P 133 The memory of a computer consists of a set of sequentially numbered locations Each location is a register in which binary information can be stored The number of a location is called its address The lowest address is 0 计算机的内存由一组连续编号的单元构成 每一个单元都是一个存 储二进制信息的寄存器 单元的编号称为其地址 最低的地址为 0 P 135 The CPU s job is to fetch instructions from memory and execute these instructions The structure of the CPU is shown in Fig 3 1A 3 It has four main components an arithmetic and logical unit ALU a set of registers an internal processor bus and controller 精品文档 6欢迎下载 CPU 的工作是从存储器中取回指令并执行 它有四个主要部件 算 术 逻辑单元 一系列存储器 一个内部处理器总线和控制器 P 163 These two types of architecture are found in single chip microcomputers Some employ the split program data memory of the Harvard architecture shown in Fig 3 4A 1 others follow the philosophy widely adopted for general purpose computers and microprocessors of making nological distinction between program and data memory as in the Princeton architecture shown in Fig 3 4A 2 单片机有这样两种结构类型 一些使用了哈佛结构的分离的程序 数 据存储器 如图 3 4A 1 所示 另一些被通用计算机和微处理器广泛 采用的是普林斯顿结构 遵循在程序存储器与数据存储器之间没有 逻辑区别的原理 如图 3 4A 2 所示 In general terms a single chip microcomputer is characterized by the incorporation of all the uints of a computer into a single device as shown in Fig 3 4A 3 概括地讲 单片机的特征是将计算机的所有部件都合并到一个单一 的装置上 如图 3 4A 3 所示 精品文档 7欢迎下载 P 164 RAM is for the storage of working variables and data used during program execution RAM 是用于程序执行过程中对工作变量和数据的存储 P 166 digtital Signal Processor is a super fast chip computer which has been optimized for the detection processing and generation of real world signals such as voice video music etc inreal time 数字信号处理器是一种超高速单片计算机 它已被优化以用于一些 现实信号如语音 视频 音乐等等的实时检测 处理和产生 Distinguishing between DSP and micro by application is perhaps not the best way forward after all In fect the main difference lies deep inside the divices themselves in the internal chip architecture with DSP devices particularly optimized for high speed high accuracy multiplication 要按应用来分辨 DSP 与微处理器可能不是最好的方法 实际上 它 们两者主要的不同存在于它们的内部芯片结构 DSP 器件对高速 高精度的乘法进行了特殊的优化 精品文档 8欢迎下载 P180 Automatic process control is concerned with maintaining process variables temperatures pressures flows compositions and the like at some desired operating valur As we shall see in the ensuing pages processes are dynamic in nature Changes are always occurring and if actions are not taken the important process variables those related to safety product quality and production rates will not achieve design conditions 自动过程控制与持续过程变量 温度 压力 流量 成分和期望操 作值一类的量有关 正如我们在后续的章节中所看到的 过程本身 是动态的 变化不断发生 并且如果激励未加入 重要的过程变量 与安全有关的变量 产品质量和生产率 将不能获得期望值 P186 There are some other common industrial sensors pressure flow temperature and level Sometimes it is important for system analysis to obtain the parameters that describe the sensor transmitter behavior 其他工业传感器有 压力 流量 温度和水平面 有时候 获得描 述传感器 热敏电阻动态性能的参数对于系统分析是很重要的 精品文档 9欢迎下载 汉译英 1 这种仪表用来测定电池充电的程度 This instrument is used to determine how fully the batteries are charged 2 电流的大小与电压成正比 与电阻成反比 An current varies di