电气工程专业英语课件lecture9-2012
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电气工程专业英语课件lecture3-2012
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Lecture 3
Other considerations for an overhead line include: the number, size, and spacing of conductors per-phase bundle; the phase to phase spacing; the number, location, and conductor type for overhead neutrals concerning with lightning shielding; the level of insulation; ect. The design of a power line depends upon the following criteria: i) The amount of active power it has to transmit. ii) The distance over which the power must be carried. iii) The cost of the power line. iv) Esthetic considerations, urban congestion, ease of installation, and expected load growth.
Lecture 3
1. As the system expands and higher voltage levels become necessary for transmission, the older transmission lines are often relegated to subtransmission function. 随着系统的扩大和更高的电压等级为输电所必需， 随着系统的扩大和更高的电压等级为输电所必需，旧 的输电线路往往被移交给中压输电功能。 的输电线路往往被移交给中压输电功能。 New Words and Expressions backbone 中枢 integrated 综合的，完整的 综合的， voltage level 电压等级 step up 升压 step down 降压 subtransmission 中压输电，次输电 中压输电， subsystem 子系统 bulk 大量的 demarcation 划分 relegate to 委托给，移交给 委托给， overhead line 架空线 cable 电缆
Lecture 3
Other considerations for an overhead line include: the number, size, and spacing of conductors per-phase bundle; the phase to phase spacing; the number, location, and conductor type for overhead neutrals concerning with lightning shielding; the level of insulation; ect. The design of a power line depends upon the following criteria: i) The amount of active power it has to transmit. ii) The distance over which the power must be carried. iii) The cost of the power line. iv) Esthetic considerations, urban congestion, ease of installation, and expected load growth.
Lecture 3
1. As the system expands and higher voltage levels become necessary for transmission, the older transmission lines are often relegated to subtransmission function. 随着系统的扩大和更高的电压等级为输电所必需， 随着系统的扩大和更高的电压等级为输电所必需，旧 的输电线路往往被移交给中压输电功能。 的输电线路往往被移交给中压输电功能。 New Words and Expressions backbone 中枢 integrated 综合的，完整的 综合的， voltage level 电压等级 step up 升压 step down 降压 subtransmission 中压输电，次输电 中压输电， subsystem 子系统 bulk 大量的 demarcation 划分 relegate to 委托给，移交给 委托给， overhead line 架空线 cable 电缆
电气专业英语基础 ppt课件
ppt课件
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常用的前缀和后缀却多达百个，可见派生法的构词 能力是非常强的。作为一个专业技术人员，至少应掌 握50个常用前缀和后缀。
前缀（prefix）：词义变化，词类不变 后缀（suffix）：词义可能变化可能不变，词 类一定会变
ppt课件
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名词前缀
前缀 auto-
含义 自动，自己，自身
counterhydr(o)
专业或技术词汇 某个专业所特有的词汇，其专业性强，词义狭窄和单一。
diode ，
(二极管)
capacitor ，
（电容器）
substation ,
(变电站，变电所)
autotransformer，（自耦变压器）
superconductivity (超导特性)。
ppt课件
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次技术词汇
很多专业和学科所共有的词汇,不同专业和学 科往往具有不同词义 power : 幂，乘方 动力，功率，效率
名词+形容词(n+adj.) →adj.： ice-cold, network-wide 名词+副词(n+adv.)→n.，adj.: feedback
形容词＋名词（adj+n）→n.，adj.：
low-pass, high-speed, short-circuit, newtype
形容词+名词+ed (adj.+n.+ed)→adj.:
隶属于科技英语 是科技英语的一部分，以表达科技概念、理论与事实为主要 目的。遵守科技英语的语法体系和翻译方法;特别注重客观事实和真理，表达准 确、精练和正式。
是结合各自专业的科技英语 有很强的专业性，涉及的面更加狭窄，与专业内 容配合更为密切。
电气工程专业英语课件lecture10-2012
Lecture 10
New Words and Expressions optimization 最优化 profit 利润 capital invested 资金投入 regulatory body 制定规章的机构 conservation 保留，节约 kilowatthour 千瓦时 unit 发电机组 delivered power 输出功率 call upon 启用
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Lecture 10
Part 2 Economic Scheduling of Plant Outputs For achieving economical operation, we shall study first the most economic distribution of the output of a plant between the generator, or units, within the plant. Since system generation is often expanded by adding units to existing plants, the various units within a plant usually have different characteristics. The method that will be developed is also applicable to economic scheduling of plant outputs for a given loading of the system without considering of transmission losses. We shall proceed to develop a method of expressing transmission loss as a function of the outputs of the various plants. Then we shall determine how the outputs of each of the plants of a system is scheduled to achieve minimum cost of power delivered to the load.
电气工程专业英语课件lecture11-2012
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Lecture 11
No network of DC lines is possible at this time because no circuit breaker is available for direct current comparable to the highly developed AC breakers. The AC breaker can extinguish the arc which is formed when the breaker opens because zero current occurs twice in each cycle. The direction and amount of power in the DC line is controlled by the converters in which grid-controlled mercury-arc devices are being displaced by the semiconductor devices. 1. Unlike overhead lines, underground cable is invisible, free from atmospheric pollution, and solves the problem of securing rights of way. 和架空线不同，地下电缆是看不见的，免受大气污染，并解 决了安全的公用通道问题。
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Hale Waihona Puke Lecture 112. DC transmission remains very limited in usage except for long lines because there is no DC device which can provide the excellent switching operations and protection of the AC circuit devices. 直流输电除用于长线（输电）以外在应用上仍然十分有限， 这是因为没有直流设备能够提供交流装置所具有的卓越的开 关操作和保护功能。 3. The direction and amount of power in the DC line is controlled by the converters in which grid-controlled mercury-arc devices are being displaced by the semiconductor devices. 直流线路上功率的流向和数量用换流器控制，其中栅控汞弧设 备正在被半导体装置取代。
Lecture 11
No network of DC lines is possible at this time because no circuit breaker is available for direct current comparable to the highly developed AC breakers. The AC breaker can extinguish the arc which is formed when the breaker opens because zero current occurs twice in each cycle. The direction and amount of power in the DC line is controlled by the converters in which grid-controlled mercury-arc devices are being displaced by the semiconductor devices. 1. Unlike overhead lines, underground cable is invisible, free from atmospheric pollution, and solves the problem of securing rights of way. 和架空线不同，地下电缆是看不见的，免受大气污染，并解 决了安全的公用通道问题。
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Hale Waihona Puke Lecture 112. DC transmission remains very limited in usage except for long lines because there is no DC device which can provide the excellent switching operations and protection of the AC circuit devices. 直流输电除用于长线（输电）以外在应用上仍然十分有限， 这是因为没有直流设备能够提供交流装置所具有的卓越的开 关操作和保护功能。 3. The direction and amount of power in the DC line is controlled by the converters in which grid-controlled mercury-arc devices are being displaced by the semiconductor devices. 直流线路上功率的流向和数量用换流器控制，其中栅控汞弧设 备正在被半导体装置取代。
电气工程专业英语课件lecture5-2012
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Lecture 5
iii) Ratio relays. iV) Differential relays. V) Pilot relays. 1. Relays are the logic elements of a protection system which sense the fault and cause the circuit-breaker trip circuits to be energized and the breakers to open their contacts. 继电器是保护系统的逻辑元件，它感知故障， 继电器是保护系统的逻辑元件，它感知故障，并使断路器 跳闸电路带电，断路器触点打开。 跳闸电路带电，断路器触点打开。
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Lecture 5
Solid-state relays are capable of providing characteristics similar to those of electromechanical relays, and in fact a number of newer characteristic shapes are available with solid-state relays. Although earlier models of these relays were prone to frequent component failure under the harsh operating environment of a substation, newer models do perform very well and are providing excellent service on HV and EHV power systems. Quite recently, relays based on microcomputers have been proposed, and are under active investigation at this time. The five relay classes often to be considered are: i) Magnitude relays. ii) Directional relays.
Lecture 5
iii) Ratio relays. iV) Differential relays. V) Pilot relays. 1. Relays are the logic elements of a protection system which sense the fault and cause the circuit-breaker trip circuits to be energized and the breakers to open their contacts. 继电器是保护系统的逻辑元件，它感知故障， 继电器是保护系统的逻辑元件，它感知故障，并使断路器 跳闸电路带电，断路器触点打开。 跳闸电路带电，断路器触点打开。
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Lecture 5
Solid-state relays are capable of providing characteristics similar to those of electromechanical relays, and in fact a number of newer characteristic shapes are available with solid-state relays. Although earlier models of these relays were prone to frequent component failure under the harsh operating environment of a substation, newer models do perform very well and are providing excellent service on HV and EHV power systems. Quite recently, relays based on microcomputers have been proposed, and are under active investigation at this time. The five relay classes often to be considered are: i) Magnitude relays. ii) Directional relays.
电气工程及其自动化专业英语ppt课件
seen, increase of current from zero to
I≈I1 causes the terminal voltage of the source to decrease linearly
V12=V=E－VS=E－RSI
Fig.1.3
In other words, the voltage drop VS across the source resistance rises in proportion to the current. This goes on until
电气工程及其自动化专业英语
Specialized English for Electrical Engineering ＆ Its Automation 戴文进 主 编 杨植新 副主编
1
Contents
• Part 1 Electrics and Electronics • Part 2 Electric Machinery • Part 3 Electrical Engineering • Part 4 Modern Computer Control
• When a load is connected to the source terminals (the circuit is then said to be loaded) and the circuit is closed, a current begins to flow round it. Now the voltage between source terminals 1 and 2 (called the terminal voltage) is not equal to its e.m.f. because of the voltage drop VS inside the source, that is, across the source resistance RS VS=RSI
电气工程专业英语课件lecture4-2012
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Lecture 4
3. This kind of loads, especially those consume energy calculated by standard coals more over 10 thousands of tons per year, has a name of high energy consuming loads. 这种负荷，尤其是那些年耗能万吨标准煤以上的负荷， 这种负荷，尤其是那些年耗能万吨标准煤以上的负荷， 被称为高耗能负荷。 被称为高耗能负荷。 New Words and Expressions high energy consuming 高耗能的 metallurgical 冶金的 settlement center 结算中心 intact 完整无缺的 agricultural irrigation 农业灌溉 compressor 压缩机 refrigerator 电冰箱 oven 烤箱，烤炉 烤箱， deep fryer 煎锅 incandescent light 白炽灯 fluorescent light 荧光灯 converter 转炉；变流器 9 转炉；
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Lecture 4
The load status is very important for a power system. The power system is called in a large mode of operation under heavy load conditions, and similarly, the term small mode for light loads. Tab. 6.1 lists some familiar loads.
Lecture 4
Lecture 4
3. This kind of loads, especially those consume energy calculated by standard coals more over 10 thousands of tons per year, has a name of high energy consuming loads. 这种负荷，尤其是那些年耗能万吨标准煤以上的负荷， 这种负荷，尤其是那些年耗能万吨标准煤以上的负荷， 被称为高耗能负荷。 被称为高耗能负荷。 New Words and Expressions high energy consuming 高耗能的 metallurgical 冶金的 settlement center 结算中心 intact 完整无缺的 agricultural irrigation 农业灌溉 compressor 压缩机 refrigerator 电冰箱 oven 烤箱，烤炉 烤箱， deep fryer 煎锅 incandescent light 白炽灯 fluorescent light 荧光灯 converter 转炉；变流器 9 转炉；
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Lecture 4
The load status is very important for a power system. The power system is called in a large mode of operation under heavy load conditions, and similarly, the term small mode for light loads. Tab. 6.1 lists some familiar loads.
Lecture 4
大学电气专业-专业英语课件-9
CNC abbr. Computerized Numerical Control 计算机数值 控制 stand for v.代表, 代替, 象征 introduce [,intrə'dju:s]vt. 传入, 引进, 提出 walk of life n. 行业，职业；地位 touch [tʌʧ] n. 触, 触觉, 接触vt. 接触, 触摸, 触及, 达到 vi. 触摸, 接近, 涉及, 提到 manufacturing [,mænjə'fækʧəriŋ]n. 制造业 adj. 制造业的 drill press n. 钻床 chuck [ʧʌk] n.扔, 抛弃vt. 用卡盘夹住 spindle ['spindl]n. 主轴，心轴，轴, 杆 pulley [‘puli] n. 滑车, 滑轮 Axes n. 轴 Accessory n. 附件, 零件, 附加物 adj. 附属的,补充的,副的 feedrate ['fi:d reit] n. 馈送率, 进料速率 Overly adv.过度地，太，非常 interpreting [in'tə:pri:tiŋ]adj. 作为说明的, 解释的
As you can easily see, there is a lot of manual intervention required to use a drill press to drill holes. A person is required to do something almost every step along the way! While this manual intervention may be acceptable for manufacturing companies if a small number of holes or workpieces must be machined, as quantities grow, so does the likelihood for fatigue due to the tediousness of the operation. And do note that we’ve used one of the simplest machining operations (drilling) for our example. There are more complicated machining operations that would require a much higher skill level (and increase the potential for mistakes resulting in scrap workpieces) of the person running the conventional machine tool. (We commonly refer to the style of machine that CNC is replacing as the conventional machine.)可以容易地看出，用钻床钻孔过程中需要许多的人工干涉。 在整个加工过程中几乎每一步都需要人工参与！虽然加工少量的孔或工件，制造 公司可以接受人工干涉，但随着数量增加，沉闷的操作可能导致厌烦。并且注意， 我们已经用一个最简单机械操作（钻孔）作为一个例子。有许多复杂的机械操作， 使用传统的机械工具，需要操作人员具有很高的技巧（并且增加了出错而带来废 品的可能）。（我们一般是指已经由CNC取代了传统机械）。
As you can easily see, there is a lot of manual intervention required to use a drill press to drill holes. A person is required to do something almost every step along the way! While this manual intervention may be acceptable for manufacturing companies if a small number of holes or workpieces must be machined, as quantities grow, so does the likelihood for fatigue due to the tediousness of the operation. And do note that we’ve used one of the simplest machining operations (drilling) for our example. There are more complicated machining operations that would require a much higher skill level (and increase the potential for mistakes resulting in scrap workpieces) of the person running the conventional machine tool. (We commonly refer to the style of machine that CNC is replacing as the conventional machine.)可以容易地看出，用钻床钻孔过程中需要许多的人工干涉。 在整个加工过程中几乎每一步都需要人工参与！虽然加工少量的孔或工件，制造 公司可以接受人工干涉，但随着数量增加，沉闷的操作可能导致厌烦。并且注意， 我们已经用一个最简单机械操作（钻孔）作为一个例子。有许多复杂的机械操作， 使用传统的机械工具，需要操作人员具有很高的技巧（并且增加了出错而带来废 品的可能）。（我们一般是指已经由CNC取代了传统机械）。
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Lecture 9
Overhead lines, depending on the load current, either absorb or supply reactive power. At loads below the natural (surge impedance) load, the lines produce net reactive power; at loads above the natural load, the lines absorb reactive power. Underground cables, owing to their high capacitance, have high natural loads. They are always loaded below their natural loads, and hence generate reactive power under all operating conditions. Transformers always absorb reactive power regardless of their loading; at no load, the shunt magnetizing reactance effects predominate; and at full load, the series leakage inductance effects predominate. Loads normally absorb reactive power. A typical load bus
Lecture 9
New Words and Expressions compensation 补偿 excitation 励磁 end-region 端部 surge impedance 波阻抗 leakage 漏电 incentive 动机
absorption 吸收 field current 励磁电流 armature 电枢 natural load 自然负荷 lt2 Objectives and Methods of Voltage Regulation For efficient and reliable operation of power systems, the control of voltage and reactive power should satisfy the following objectives: i) Voltages at the terminals of all equipment in the system are within acceptable limits. Both utility equipment and customers equipment are designed to operate at a certain voltage rating. Prolonged operation of the equipment at voltage outside the allowable range could adversely affect their performance and possibly cause them damage. ii) System stability is enhanced to maximize utilization of the transmission system. As described in some academic papers, voltage and reactive power control have a significant impact on 6 system stability.
Specialized English for Electrical Engineering
各位老师：
上午好！
Lecture 9
1
Lecture 9
Reading and Translation
Voltage Regulation and Reactive Power Compensation
Part 1 Production and Absorption of Reactive Power Bus voltage will change according to load flow variation, whereas they are mainly affected by production and absorption of reactive power at those buses. Synchronous generators can generate or absorb reactive power depending on the excitation. When overexcited they supply reactive power, and when underexcited they absorb reactive power. The capability to continuously supply or absorb reactive power is, however, limited by the filed current, 2 armature current, and end-region heating limits.
Lecture 9
compensators (SVCs). ii) Line reactance compensators, such as series capacitors. iii) Regulating transformers, such as tap-changing transformers and boosters. Shunt capacitors and reactors, and series capacitors provide passive compensation. They are either permanently connected to the transmission and distribution system, or switched. They contribute to voltage control by modifying the network characteristics. Synchronous condensers and SVCs provide active compensation; the reactive power absorbed/supplied by them is automatically adjusted so as to maintain voltages of the buses to which they are connected. Together with the generating units, they establish voltages at specific points in the system. 9
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Lecture 9
overall system active power balance. The proper selection and coordination of equipment for controlling reactive power and voltage are among the major challenges of power system engineering. The control of voltage levels is accomplished by controlling the production, absorption, and flow of reactive power at all levels in the system. The generating units provide the basic means of voltage control; the automatic voltage regulators (AVRs) control field excitation to maintain a scheduled voltage level at the terminals of the generators. Additional means are usually required to control voltage throughout the system. The devices used for this purpose may be classified as follows: i) Sources or sinks reactive power, such as shunt capacitors, shunt reactors, synchronous condensers, and static var 8
Lecture 9
iii) The reactive power flow is minimized so as to reduce RI 2 and XI 2 losses to a practical minimum. This ensures that the transmission system operates efficiently, i. e. , mainly for active power transfer. The problem of maintaining voltages within the required limits is complicated by the fact that the power system supplies power to a vast number of loads and is fed from many generating units. As loads vary, the reactive power requirements of the transmission system vary. This is abundantly clear from the performance characteristics of transmission lines. Since reactive power cannot be transmitted over long distances, voltage control has to be effected by using special devices dispersed throughout the system. This is in contrast to the control of frequency which depends on the