电气专业英语翻译
电气专业英语单词翻译
A priori knowledge 先验知识Actuator 执行器Ad hoc 尤其关于Addition 加Ambient 环境的Americana 美国志书Analog-to-digital converter ，模拟数字转换器Antenna 天线Arrangement 方案Automate 使自动化Averaging 求平均值Be subtracted from 减Binary 二进制的Bus network 总线网Carbon-filament lamp 碳丝灯泡Carrier frequency 载频Carrier sense multiple access with collision detection 载波监听，多址访问Cellular telephone 蜂窝式电话系统Circuit components 电路元件Circuit diagram 电路图Circuit parameters 电路参数Close-loop control 闭环控制Common media 公共媒体Common reference 参考点Conductance 电导Conductor 导体Consistently 稳定，协调Constant coefficient system 常系数系统Control installation 控制装置Convention 惯例Conventional 常见的Conversion 转换Correct 校正Corresponding to 相应的Crossbar switch 纵横切换器Differential input 差动输入Differentiation 微分Digital-to-analog converter 数字模拟转换器Dimensional 量纲的Direct-current circuit 直流电路Discrete-time system 离散时间系统Discrimination 分辨力鉴别力Displacement current 位移电流Distinction 区别Disturb 扰动Dummy 假的，假装的Dynamic behavior 动态行为Electric circuit 电路Electric energy 电能Electrical device 电气设备Electrical pressure transducer 压电传感器Electromotive force 电动势Electronic analog 电子模拟Encyclopedia 百科全书Energy converter 电能转换器Energy source 电源Ergonomic 人类工程学的Error 误差Excursion 偏差Existing value 实际值External characteristic 外特性Facsimile 传真Factor 系数，因率数Feedback 反馈Feedback component 反馈元件Frequency counter 频率计数器Frequency-domain 频域Function 功能Generator 发电机Graphic panel 图式仪表盘Heating appliance 电热器High definition television 高清电视Hybrid system 混合系统Ideal amplifier 理想放大器Immunity 不敏感性Income 输入Indicator 指示Inertia 惯性Inertia reference frame 惯性参考坐标系Infinite voltage gain 无穷大电压增益Initial voltage 初始电压Input quantity 输入量Integrated service digital network综合业务数据网Integration 积分Internal combustion engine 内燃机Interruption 阻断Intervention 介入Inverting amplifier 反相放大器Inverting terminal 反相端Linear vector space 线性向量空间Linearization 线性化Load characteristic 负载特性Load resistance 负载特性Logic level 逻辑电平Logistic 后勤的Lower limit on the integration 积分下限Low-order system 低阶系统Low-pass filter 低通滤波器Machine tool 机床Magnetic and electric field 电磁场Manual 手工Manufacturer’s data sheet 铭牌Mathematical operation 数字运算Measuring technique 测试技术Megohm 兆欧Metal-filament lamp 金属丝灯泡Metropolitan area network 城域网Microvolt 微伏Modern control theory 现代控制理论Multiplexer 多路切换器Multiplication 乘Negative-feedback signal 负反馈信号Noise 噪声Noninverting terminal 非反相端Nonlinear 非线性的Off-set 失常点Offset=bias 偏置On-line system 联机系统Ono-linear characteristics 非线性特性Open loop gain 开环增益Open-loop control 开环控制Operational amplifier 运算放大器Optimal control 最优控制Opto-isolator 观点耦合器Order 数量级Outset 开始Parallel digital signal 并行数字信号Pervasive 普遍性的Phase reversal 反相Phase-plane method 像平面方法Potentiometer 电位计Preset 预先装置Primary cell 原生电池Private networks 专业网络Public network 公用网络Radix-weighted 基数加权Rated 额定的Research and design 研发Resolution 分辨力Ring network 环形网Scaling 量程调整Schematic 纲要的Schmitt-trigger 施密特触发器Secondary cell 再生电池Self-(or mutual-) induction 自（互）感Self-acting 自动做Self-moving 自运动Servooperated null-balance potentiometer 伺服驱动零平衡电位差计Shaft encoder 转轴编码的Shunt connection 并联连接Signal conditioning 信号调理Signal conditioning 信号处理Simultaneous equations 联立方程Single-ended output 单端输出Sink 灌入Source 从出来Span 量程Specification 参数Square root extraction 开平方State variable method 状态变量方法Storage battery 蓄电池Strain gage 应变仪Strip chart 长条记录纸Substrate 底层基片Subtraction 减Synchros 感应同步器System buses 系统总线Telecommunication 远程通信Terminal voltage 端电压The dielectric 电介质Time-domain technique 时间域技术Time-invariant 定常的Time-varying parameter 时变参数Timing circuit 计时电路Token 令牌Topology 拓扑Transducer 传感器Transfer function 传递函数Transformer 变压器Triangular symbol 三角符号Uncertainty 不确定性Unidirectional current 单方向性电流Upgrade 升级Virtual 虚的Virtual ground 虚地Voltage drop 电压降Volt-ampere characteristics 伏安特性Wire 导线Zero adjustment 零位调整。
电气工程专业英语翻译
实用资料：电气工程专业课(电力类)翻译参考专业外语：Professional English电路（上） electrical circuit (I)电路（下） electrical circuit (II)金工实习 machinery practice电机（上） electrical machinery (I)电工实验与测试 electrical experiment & test电子综合实践 integrated electronic practice信号与系统 signal & system电子技术基础（模拟） fundamentals of electronic (analog)电磁场electromagnetic field电子技术实验 electronic experiment(I)电子辅助设计EDA Electronic Design Automatic(I)发电厂动力工程基础 Heat power engineering in generating plant企业管理 enterprise management电气主系统electrical system principle电力系统稳态/暂态分析 Steady-State/ Transient-State Analysis of Power System 电力系统继电保护 Power System Relaying Protection电力系统潮流计算机分析：Computer Analysis of Power Flow数字电子技术 Digital Electrical Technique微机原理 microcomputer principle电子技术基础（数字） fundamentals of electronic (digital)自动控制 automatic control theory电力系统分析 electric power system analysis电子技术基础实验electronic experiment(II)电气主系统课程设计 electrical system principle-course design电子辅助设计EDA Electronic Design Automatic(II)通信与计算机网络 communication & computer networks电力系统继电保护 electric power system relaying电力系统继电保护 Power System Protective Relaying电力系统远动技术electric power system remote protocol生产实习productive practice Technology继电保护课程设计 electric power system relaying-course design电力电子技术 power electronics电力电子技术基础：Fundamentals of Electronics Power Technology电力电子课程设计 Power electronics course design电力系统自动控制 electric power system control & automation高电压技术 High voltage engineering Technology变电站自动化 substation automation电力经济 electric power system economics电能质量控制 electric power quality control配电网自动化 distribution system automation电力系统新技术 new techniques on electric power system控制电机 electrical machine control调度自动化与能量管理 energy management & automation灵活交流输电系统 flexible AC transmission system计算机保护 computer protection电力系统电磁兼容 EMC in electric power system毕业实习graduation practice毕业设计graduation dissertation数字信号处理：Digital Signal Processing自动控制理论：Automatic Control Theory电气工程基础：Fundamentals of Electrical Engineering电磁场概论：Introduction to Electro-Magnetic Field计算机继电保护：Microcomputer-Based Relaying Protection电气设备的绝缘检测与故障诊断：Insulation Diagnostics and Troubl-Shooting for Electrical Installations电网规划：Power System Planning可编程控制器原理及应用：Principles of PLC (Programmable logic Controller) And Application电磁场数值计算：Numerical Computation of Electro-Magnetic Field电力系统继电保护：Relay Protection of Power System电力系统自动装置原理 The Principle of Electric Power System Automatic Equipment 电力通信系统及调度自动化：Power System Communication and Dispatching Automatic专业方向电气工程 Electrical Engineering电机与电器 Electric Machines and Electric Apparatus电力系统及其自动化 Power System and its Automation高电压与绝缘技术 High Voltage and Insulation Technology电力电子与电力传动 Power Electronics and Power Drives电工理论与新技术 Theory and New Technology of Electrical Engineering电子科学与技术 Electronics Science and Technology。
电气专业英语课文翻译
An electric circuit (or network) is an interconnection of physical electrical device. The purpose of electric circuits is to distribute and convert energy into some other forms. Accordingly , the basic circuit components are an energy source (or sources), an energy converter (or converters) and conductors connecting them. 电路（或者网络）是物理电气设备的一种互相连接。
电路的目的是为了将能量分配和转换到另外一种形式中。
因此，基本的电路元件包括电源、电能转换器以及连接它们的导体。
式中。
因此，基本的电路元件包括电源、电能转换器以及连接它们的导体。
An energy source (a primary or secondary cell, a generator and the like) converts chemical, mechanical, thermal or some some other other other forms forms forms of of of energy energy energy into into into electric electric electric energy. energy. An energy energy converter, converter, converter, also also also called called called load load load (such (such (such as as as a a a lamp, lamp, lamp, heating heating appliance or electric motor), converts electric energy into light, heat, mechanical work and so on. 电源（原生电池或者再生电池、发电机等类似装备）将化学能量、机械能量，热能或者其他形式的能量转换成电能。
电气信息类专业英语翻译
Lesson 1 electronic network1、短语及词汇：Electronic circuit or network ——电路或电网络Passive network ——无源网络 active network ——有源网络V oltage source ——电压源 current source ——电流源in the case of …——就…来说 Rather than ——是…而不是… of interest ——有价值的；使人感兴趣的；有意义的；2、重点句型（1）in the case of a resistor, the voltage-current relationgship 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上流过的电流乘以电阻值（2）it may be that the inductor voltage rather than the current is the variable of interest in the circuit.或许在电路中，人们感兴趣的是电感电压而不是电感电流3、文章内容翻译（见参考译文并在课堂上讲解）对应译文：电网络电路或电网络是由电阻、电感和电容等器件以某种方式联接在一起所组成的。
如果电网络中不包含任何能源，比如电池和发电机，就叫做无源网络。
相反，如果存在一个或多个能源，则组合的系统(电网络)则称为有源网络。
当研究电网络的特性时，我们感兴趣的是电路中的电压和电流。
既然网络是由无源元件组成的，我们就必须首先来定义它们的电特性。
电气工程专业英语汉语及翻译
电气工程专业英语姓名：吕海龙学号：20080345班级：08电气专业：电气工程及其自动化Electric Devices and SystemsAlthough transformers have no moving parts , they are essential to electromechanical energy conversion . They make it possible to increase or decrease the voltage lever that results in low costs ,and can be distributed and used safely . In addition , they can provide matching of impedances , and regulate the flow of power in a network.When we see a transformer on a utility pole all we is a cylinder with a few w ires sticking out. These wires enter the transformer through bushings that provide isolation between the wires and the tank. Inside the tank these is an iron core linking coils, most probably made with copper, and insulated. The system of insulation is also associated with that of cooling the core/coil assembly. Often the insulation is paper, and the whole assembly may be immersed in insulating oil, used to both increase the dielectric strength of the paper and to transfer beat from the core-coil assembly to the outer walls of the tank to air. Figure shows the cutout of a typical distribution transformer.Few ideal versions of human constructions exist, and the transformer offers no exception. An ideal transformer is based on very simple concepts, and a large number of assumptions. This is the transformer one learns about in high school.Let us take an iron core with infinite permeability and two coils wound around it, one with N1 and the other with N2 turns, as shown in figure. All the magnetic flux is to remain in the iron. We assign sots at one terminal of each coil in the following fashion: if the flux in the core changes, inducing a voltage in the coils, and the dotted terminal of one coil is positive with respect its other terminal, so is the dotted terminal of the other coil. Or, the corollary to this, current into dotted terminals produces flux in the same direction,Assume that somehow a time varying flux is established in the iron. Then the flux linkages in each coil will be. V oltages will be induced in these two coil.On the other hand, currents flowing in the coils are related to the field intensity H. if currents flowing in the direction shown, i1 into the dotted terminal of coil 1, and i2 out of the dotted terminal of coil 2. we recognize that this is practically impossible, but so is the existence of an ideal transformer.Equations describe this ideal transformer, a two port network. The symbol of a network that is defined by these two equations is in the figure. An ideal transformer has an interesting characteristic. A two-port network that contains it and impedances can be replaced by an equivalent other, as discussed below. Consider the circuit in figure. Seen as a two port network. Generally a circuit on a side 1 can be transferred to side 2 by multiplying its component impedances , the voltage sources and the current sources, while keeping the topology the same.To develop the equivalent for a transformer we’ll gradually relax the assumptions that we had first imposed. First we’ll relax the assumption that the permeability of the iron is infinite. In that case equation does not revert to, but rather it becomes where is the reluctance of the path around the core of the transformer and the flux on this path. To preserve the ideal transformer equations as part of our new transformer, we can split i1 to two components: one i1, will satisfy the ideal transformer equation, and the other, i1 will just balance the right hand side. The figure shows this.We can replace the current source, i1 , with something simpler if we remember that the rate of change of flux is related to the induced voltage.Since the current i1 flows through something , where the voltage across it Is proportional to its derivative, we can consider that this something could be an inductance. This idea gives rise tothe equivalent circuit in figure,. Let us now relax the assumption that all the flux has to remain in the iron as shown in figure. Let us call the flux in the iron, magnetizing flux, the flux that leaks out of the core and links only coil 1. since links only coil 1, then it should be related only to the current there, and the same should be true for the second leakage flux.Again for a given frequency, the power losses in the core increase with the voltage. These losses cannot be allowed to exceed limit, beyond which the temperature of the hottest spot in the transformer will rise above the point that will decrease dramatically the life of the insulation. Limits therefore are put to E1 and E2, and these limits are the voltage limits of the transformer.Similarly, winding Joule losses have to be limited, resulting in limits to the currents I1 and I2.Typically a transformer is described by its rated voltages, that give both the limits and turns radio. The ratio of the rated currents is the inverse of the ratio of the voltages if we neglect the magnetizing current. Instead of the transformer rated currents, a transformer is described by its rated apparent power.Under rated conditions, maximum current and voltage, in typical transformers the magnetizing current, does not exceed 1% of the current in the transformer. Its effect therefore in the voltage drop on the leakage inductance and winding resistance is negligible.Under maximum current, total voltage drops on the winding resistances and leakage inductances do not exceed in typical transformer 6% of the rated voltage. The effect therefore of the winding current on the voltages E1 and E2 is small, and their effect on the magnetizing current can be neglected.These considerations allow us to modify the equivalent circuit in figure, to obtain the slightly inaccurate but much more useful equivalent circuits in figures.Adjustable Speed DrivesBy definition, adjustable speed drives of any type provide a means of variably changing speed to better match operating requirements. Such drives are available in mechanical, fluid and electrical typed.The most common mechanical versions use combinations of belts and sheaves, or chains and sprockets, to adjust speed in set, selectable ratios-2:1,4:1,8:1 and so forth. Traction drives, a more sophisticated mechanical control scheme, allow incremental speed adjustments. Here, output speed is varied by changing the contact points between metallic disks, or between balls and cones.Adjustable speed fluid drives provide smooth, stepless adjustable speed control. There are three major types. Hydrostatic drives use electric motors or internal combustion engines as prime movers in combination with hydraulic pumps, which in turn drive hydraulic motors. Hydrokinetic and hydroviscous drives directly couple input and output shafts. Hydrokinetic versions adjust speed by varying the amount of fluid in a vortex that serves as the input-to-output coupler. Hydroviscous drives, also called oil shear drives, adjust speed by controlling oil-film thickness, and therefore slippage, between rotating metallic disk.An eddy current drive, while technically an electrical drive, nevertheless functions much like a hydrokinetic or hydrovidcous fluid drive in that it serves as a coupler between a prime mover and driven load. In an eddy current drive, the coupling consists of a primary magnetic field and secondary fields created by induced eddy currents. They amount of magnetic slippage allowed among the fields controls the driving speed.In most industrial applications, mechanical, fluid or eddy current drives are paired with constant-speed electric motors. On the other hand, solid state electrical drives, create adjustable speed motors, allowing speeds from zero RPM to beyond the motor’s base speed. Controlling the speed of the motor has several benefits, including increased energy efficiency by eliminating energy losses in mechanical speed changing devices. In addition, by reducing, or often eliminating, the need for wear-prone mechanical components, electrical drives foster increased overall system reliability, as well as lower maintenance costs. For these and other reasons, electrical drives are the fastest growing type of adjustable speed drive..There are two basic drive types related to the type of motor controlled-dc and AC. A DC direct current drive controls the speed of a DC motor by varying the armature voltage (and sometimes also the field voltage ). An alternating current drive controls the speed of an AC motor by varying the frequency and voltage supplied to the motor.Direct current drives are easy to apply and technologically straightforward, They work by rectifying AC voltage from the power line to DC voltage, then feeding adjustable voltage to a DC motor. With permanent magnet DC motors, only the armature voltage is controlled. The more voltage supplied, the faster the armature turns. With wound-field motors, voltage must be supplied to both the armature and the field. In industry, the following three types of DC drives are most common, as shown in the figure.Drives: these are named for the silicon controlled rectifiers (also called thyristors ) used to convert AC to controlled voltage DC. Inexpensive and easy to use, these drives come in a variety of enclosures, and in unidirectional or reversing styles.Regenerative SCR Drives: Also called four quadrant drives, these allow the DC motor to provide both motoring and braking torque, Power coming back from the motor during braking is regenerated back to the power line and not lost.Pulse Width Modulated DC Drives: Abbreviated PWM and also called, generically, transistorized DC drives, these provide smoother speed control with higher efficiency and less motor heating, Unlike SCR drives, PWM types have three elements. The first converts AC to DC, the second filters and regulates the fixed DC voltage, and the third controls average voltage by creating a stream of variable width DC pulses. The filtering section and higher level of control modulation account for the PWM drive’s improved performance compared with a common SCR drive.AC drive operation begins in much the same fashion as a DC drive. Alternating line voltage is first rectified to produce DC. But because an AC motor is used, this DC voltage must be changed back, of inverted, to an adjustable-frequency alternating voltage. The drive’s inverter section accomplishes this, In years past, this was accomplished using SCR. However, modern AC drives use a series of transistors to invert DC to adjustable-Frequency AC. An example is shown in figure.This synthesized alternating current is then fed to the AC motor at the frequency and voltage required to produce the desired motor speed. For example, a 60 Hz synthesized frequency, the same as standard line frequency in the United states, produces 100% of rated motor speed. A lower frequency produces a lower speed, and a higher frequency a higher speed. In this way, an AC drive can produce motor speeds from, approximately,15 to200% of a motor’s normally rated RPM-- by delivering frequencies of 9 HZ to 120 Hz, respectively.Today, AC drives are becoming the systems of choice in many industries,. Their use ofsimple and rugged three-phase induction motor means that AC drive systems are the most reliab le and least maintenance prone of all. Plus, microprocessor advancements have enabled the creation of so-called vector drives, which provide greatly enhance response, operation down to zero speed and positioning accuracy. V ector drives, especially when combined with feedback devices such as tachometers, encoders and resolvers in a closed-loop system, are continuing to replace DC drives in demanding applications. An Example is shown in the figure.By far the most popular AC drive today is the pulse width modulated type. Though originally developed for smaller-horsepower applications, PWM is now used in drives of hundreds or even thousands of horsepower—as well as remaining the staple technology in the vast majority of small integral and fractional horsepower ―micro‖ and ―sub-micro‖ AC drives, as shown in the figure.Pulse width modulated refers to the inverter’s ability to vary the output voltage to the motor by altering the width and polarity of voltage pulses, The voltage and frequency are synthesized using this stream of voltage pulses. This is accomplished through microprocessor commands to a series of power semiconductors that serve as on-off switches. Today, these switches are usually IGBTs, of isolated gate bipolar transistor. A big advantage to these devices is their fast switching speed resulting in higher pulse of carrier frequency, which minimizes motor noise.Power semiconductor devicesThe modern age of power electronics began with the introduction of thyristors in the late 1950s. Now there are several types of power devices available for high-power and high-frequency applications. The most notable power devices are gate turn-off thyristor, power darlington transistors, power mosfets, and insulated-gate bipolar transistors. Power semiconductor devices are the most important functional elements in all power conversion applications. The power devices are mainly used as switches to convert power from one form to another. They are used in motor control systems, uninterrupted power supplies, high-voltage dc transmission, power supplies, induction heating, and in many other power conversion applications. A review of the basic characteristics of these power devices is presented in this section.The thyristor, also called a silicon-controlled rectifier, is basically a four-layer three-junction pn device. It has three terminals: anode, cathode, and gate. The device is turned on by applying a short pulse across the gate and cathode. Once the device turns on, the gate loses its control to turn off the device. The turn-off is achieved by applying a reverse voltage across the anode and cathode. The thyristors symbol and its volt-ampere characteristics are shown in the figure. There are basically two classifications of thyristors: converter grade and inverter grade. The difference between a converter-grade and an inverter-grade thyristor is the low turn –off time (on the order of a few microseconds) for the latter. The converter-grade thyristors are slow type and are used in natural commutation (or phase-controlled) applications. Inverter-grade thyristors are used in forced commutation applications such as dc-dc choppers and dc-ac inverters. The inverter-grade thyristors are turned off by forcing the current to zero using an external commutation circuit. This requires additional commutating components, thus resulting in additional losses in the inverter.Thyristors are highly rugged devices in terms of transient currents, di / dt, and dv/dt capability. The forward voltage drop in thyristors is about 1.5 to 2 V, and even at higher currents of the order of 100 A, it seldom exceeds 3 V. While the forward voltage determines the on-state power loss of the device at any given current, the switching power loss becomes a dominating factor affecting the device junction temperature at high operating frequencies. Because of this, themaximum switching frequencies possible using thyristors are limited in comparison with other power devices considered in this section.Thyristors have withstand capability and can be protected by fuses. The nonrepetitive surge current capability for thyristors is about 10 times their rated root mean square current. They must be protected by snubber networks for dv/dt and di/dt effects. If the specified dv/dt is exceeded, thyristors may start conducting without applying a gate pulse. In dc-to-ac conversion applications it is necessary to use an antiparalled diode of similar rating across each main thyristor. Thyristors are available up to 6000 V, 3500 A.Power mosfets are marketed by different manufacturers with differences in internal geometry and with different names such as megamos, hexfet, sipmos, and tmos. They have unique features that make them potentially attractive for switching applications. They are essentially voltage-driven rather than current-driven devices, unlike bipolar transistors.The gate of a mosfet is isolated electrically from the source by a layer of silicon oxide. The gate draws only a minute leakage current of the order of nanoamperes. Hence the gate drive circuit is simple and power loss in the gate control circuit is practically negligible. Although in steady state the gate draws virtually no current, this is not so under transient conditions. The gate-to-source and gate-to-drain capacitances have to be charged and discharged appropriately to obtain the desired switching speed, and the drive circuit must have a sufficiently to output impedance to supply the required charging and discharging currents. The circuit symbol of a power mosfet is shown in the figure.Power mosfets are majority carrier devices, and there is no minority carrier storage time. Hence they have exceptionally fast rise and fall times. They are essentially resistive devices when turned on, while bipolar transistors present a more or less constant over the normal operating range. Power dissipation in mosfets is I, and in bipolar it is Ic, and in bipolar it is Id. At low currents, therefore, a power mosfet may have a lower conduction loss than a comparable bipolar device, but at higher currents, the conduction loss will exceed that of bipolar. Also, the R increases with temperature.An important feature of a power mosfet is the absence of a secondary breakdown effect, which is present in a bipolar transistor, and as a result, it has an extremely rugged switching performance. In mosfets, R increases with temperature, and thus the current is automatically diverted away from the hot spot. The drain body junction appears as an antiparalled diode between source and drain. Thus power mosfet will not support voltage in the reverse direction. Although this in verse diode is relatively fast, it is slow by comparison with the mosfet. Recent devices have the didde recovery time as low as 100 ns. Since mosfet cannot be protected by fuses, an electronic protection technique has to be used.With the advancement in MOS technology, ruggedized MOSF are replacing the conventional MOSEFs. The need to ruggedize power MOSFETs is related to device reliability. If a MOSFET is operating within its specification range at all times, its chances for failing catastrophically are minimal. However, if its absolute maximum rating is exceeded, failure probability increases dramatically. Under actual operating conditions, a MOSFET may be subjected to transients—either externally from the power bus supplying the circuit or from the circuit itself due, for example, to inductive kicks going beyond the absolute maximum ratings. Such conditions are likely in almost every application, and in most cases are beyond a designer’s control. Rugged devices are made to be more tolerant for over-voltage transients. Ruggedness is the ability of aMOSFET to operate in an environment of dynamic electrical stresses, without activating any of the parasitic bipolar junction transistors. The rugged device can withstand higher levels of diode recovery dv/dt and static dv/dt.（单词量：3115）译文：变压器尽管变压器没有旋转的不见，但是它在本质上还是属于几点能量交换设备。
电气英语翻译专业词汇
电气工程词汇voltage电压diode二极管current电流potentiometer电位器resistance电阻step-uptransformer升压变压器reactance电抗powersystem电力系统,电网impedance阻抗transmissionline输电线conductance电导breaker断路器inductance电感relay继电器inductor电感器demodulator解调器capacitance电容radiator散热器capacitive电容性的，电容的ventilation通风，换气，通风装置shuntcapacitor并联电容器alternatingrelay交流继电器shunt并联integratedcircuitamplifier集成电路放大器series串联transistoramplifier晶体管放大器seriescircuit串联电路terminal端子parallelcircuit并联电路amplifier/magnifier放大器conductor导线cablen电缆v架设电缆voltmeter电压表fuse保险丝熔断器ammeter电流表interface接口arc电弧amplitude振幅幅度波幅chargen电荷v充电，带电，起电digitalsignal数字信号dischargev放电coupling耦合bridge电桥intermittent周期的valve电子管dislocation错位deenergize断路malfunction故障dielectric不导电的/绝缘的medium介质generator发电机screen屏蔽motor电动机dampen阻尼audion三极管socket插孔groundplane接地层alternatingcurrent交流电流three-phasen三相inverting反相potentialdifference电位差outofphase异相activeelement有源元件self-inductor自感idealindependentsource理想独立电源mutual-inductor互感watthourmeter感应线圈ampere安培frequencychanger变频器coulomb库仑controlswitch控制开关joule焦耳selectorswitch选择开关resistor电阻器currenttransformer电流互感器charger充电器powertransformer电力变压器semiconductor半导体phasevoltage相电压absolutevalue绝对值constantvoltagesource恒定电压源operatingsupplyvoltage电源工作电压专业词汇Isolator刀闸(隔离开关)定串联电容补偿Susceptance电纳voltagestability电压稳定regulator稳压器anglestability功角稳定admittance导纳installedcapacity装机容量rectifier整流器transformersubstation变电站busbar母线degreeofcompensation补偿度analogsignal模拟信号linedropcompensation（LDC）线路补偿asynchronism异步器synchronization同步circuittheorems电路定理armature电枢superpositiontheorem叠加定理attenuate衰减substitutiontheorem替代定理steam-turbine-drivengenerator气轮发thevenin-NortonTheorem戴维宁定理电机electromagnetism电磁;电磁学turbinegenerator涡轮发电机low-frequencyamplifier低频放大器magneticflux磁通量low-frequencybypass低频旁路oscilloscope示波器voltagedistortion交流电压校准器oscillator震荡器SingleChipMicroprocessor(SCM)单片机multimeter万用表alternatingcurrent(AC)交流/交流电overlay叠加效果adjustablepressureconveyor调压输送ratedpower额定功率机poweramplifier功率放大器allowableloadimpedance允许的负载阻activevoltage有效电压抗voltagetocurrentconverter电压电流closedloopcontrol闭环控制变换器closedloopvoltagegain闭环电压增益transformersubstation变电站closed-loopgain死循环增益regulation调节clutch离合器/联轴器degreeofcompensation补偿度commutator/rectifier整流器highvoltageshuntreactor高抗cutoffvoltage临界电压reactivepowercompensation无功补偿cut-involtage闭合电压three-columntransformer三绕组变压器dielectricadj.不导电的/绝缘的double-columntransformer双绕组变压器dielectricpuncture击穿power-factor功率因数electricaldurability电寿命（万次）voltagegrade电压等级electromagneticresonance电磁感应no-loadcurrent空载电流electromotiveforce电动力/电动势impedance阻抗positivecharge正电荷positivesequenceimpedance正序阻抗negativecharge负电荷negativesequenceimpedance负序阻抗AutomaticGenerationControl(AGC)自动zerosequenceimpedance零序阻抗发电控制susceptance电纳PowerSystemStabilizator(PSS)电力系stator定子统稳定器highvoltage高压polyphase多相(的) fixedseriescapacitorcompensation固iron-loss铁损armaturecircuit电枢电路interface接口dynamicresponse动态响应demodulator解调器timeinvariantadj.时不变的balanceindicator交流平衡指示器self-inductor自感currentcalibrator交流电流校准器mutual-inductor互感resistancebox交流电阻箱polarity极性voltagedistortion交流电压校准器ventilation通风，换气，通风装置standardresistor交流标准电阻器low-frequencybypass低频旁路directcurrent（DC）直流电powerpool联合电力系统；联合电网eddycurrent涡流electromagnetism电磁;电磁学corridor通路core/shellforme铁心式/壳式inducedcurrent感生电流potentialdifference电位差laminatedcore叠片铁芯dualin-linepackages双列直插式组件left-handrule左手定则automaticcontrolsystem自动控制系统volt-amperecharacteristics伏安特性torquemotor力矩电动机simulationanalysis仿真分析amplifierusingdiscrete分离元件放大onemachine-infinitybussystem单机器无穷大系统potentiometer电位器ElectricalMachinery电机学voltage-currentcharacteristic伏安特AutomaticControlTheory自动控制理论性ElectrotechnicsPrincipleofCircuits topology拓扑电工学termocouple热电偶ElectricalDriveandControl电力传动与exitation激发;激励;干扰控制air-gap气隙brownout节约用电polyphasen.多相adj.多相的cathode阴板、负极breakdowntorque失步转矩cationexchanger阳离子交换器locked-rotortorque止转转矩circuitbreaker电路断路器nominalfrequency额定频率circuitdiagram电路图subtransmission二次输电coaxialcable同轴电缆hydro-generation水力发电coolingtower冷却塔feeder馈线;馈电电路intermediaterelay中间继电器thermalunit热力机组jumper跳线、跨接activepowerbalance有功功率平衡lightningarrestor避雷器load-frequencycontrol（LFC）负荷频率installedcapacity装机容量控制instrumentpanel仪表盘sychronouscondenser同步调相机tap-changingtransformer可调分接头变压器tapcoil跳闸线圈magneticaircircuitbreaker磁吹断路器automaticgenerationcontrol（AGC）自动发电控制circuitboard电路板i nstantaneouspower瞬时功率lossofexcitation励磁损失manualreject手动切换overheadline架空线plantloadfactor电厂负荷因数potentialtransformer电压互感器overspeedtrip超速跳闸pyod热电偶safepotential安全电压shield屏蔽层WORD格式singlebladeswitch单刀开关starconnectedsystem星形连接制"Y"staticstorage静态存储器stationcapacity发电厂容量step-downtransformer降压变压器substation变电站、子站subtransmission二次输电thermalpowerplant热力发电厂thumbrule安培右手定则trip跳闸、断开starconnectedsystem星形连接制"Y"A/Cadaptor电源适配器analogtodigital模拟/数字转换acinducedpolarizationinstrument交流激电仪adjustablepressureconveyor调压输送机allowableloadimpedance允许的负载阻抗chargeneutrality电中性区ChargeTerminationVoltage允电端电压/允电端接电压circuitdiagram电路板circuitswitching电路交换closed-loopvoltagegain死循环电压增益connectors插接器constantvoltagemodulation稳压调节currentattenuation电流减衰装置CurrentbyPhase(AMP)每相电流currentlimitativerange电流限制范围cutoffvoltage临界电压cut-involtage闭合电压DischargeTerminationVoltage放电端电压dropoutvoltage跌落电压eddycurrent涡电流electormagneticbrakingsytem电磁制动系统electricdipole电偶极子electricshielding电屏蔽FrequencyHopping跳频input-outputcontrolsystem(IOCS)输入输出控制系统offsetvoltage失调电压。
电气英语翻译专业词汇
电气工程词汇voltage 电压current 电流resistance 电阻reactance 电抗impedance 阻抗conductance 电导inductance 电感inductor 电感器capacitance 电容capacitive 电容性的，电容的shunt capacitor 并联电容器shunt 并联series 串联series circuit 串联电路parallel circuit 并联电路conductor 导线voltmeter 电压表ammeter 电流表arc 电弧charge n 电荷v充电，带电，起电discharge v 放电bridge 电桥valve 电子管deenergize 断路dielectric 不导电的/绝缘的generator 发电机motor 电动机audion 三极管diode 二极管potentiometer 电位器step-up transformer 升压变压器power system 电力系统,电网transmission line 输电线breaker 断路器relay 继电器demodulator 解调器radiator 散热器ventilation 通风，换气，通风装置alternating relay 交流继电器integrated circuit amplifier 集成电路放大器transistor amplifier 晶体管放大器terminal 端子amplifier/magnifier 放大器cable n 电缆v架设电缆fuse 保险丝熔断器interface 接口amplitude 振幅幅度波幅digital signal 数字信号coupling 耦合intermittent 周期的dislocation 错位malfunction 故障medium 介质screen 屏蔽dampen 阻尼socket 插孔ground plane 接地层three-phasen 三相potential difference 电位差active element 有源元件ideal independent source 理想独立电源watt hour meter 感应线圈frequency changer 变频器control switch 控制开关selector switch 选择开关current transformer 电流互感器power transformer 电力变压器phase voltage 相电压constant voltage source 恒定电压源alternating current 交流电流inverting 反相out of phase 异相self-inductor 自感mutual-inductor 互感ampere 安培coulomb 库仑joule 焦耳resistor 电阻器charger 充电器semiconductor 半导体absolute value 绝对值operating supply voltage 电源工作电压专业词汇Isolator 刀闸(隔离开关) Susceptance 电纳regulator 稳压器admittance 导纳rectifier 整流器busbar 母线analog signal 模拟信号asynchronism 异步synchronization 同步armature 电枢attenuate 衰减steam-turbine-driven generator 气轮发电机turbine generator 涡轮发电机magnetic flux 磁通量oscilloscope 示波器oscillator 震荡器multimeter 万用表overlay 叠加效果rated power 额定功率power amplifier 功率放大器active voltage 有效电压voltage to current converter 电压电流变换器transformer substation变电站regulation 调节degree of compensation补偿度high voltage shunt reactor高抗reactive power compensation无功补偿three-column transformer三绕组变压器double-column transformer双绕组变压器power-factor 功率因数voltage grade 电压等级no-load current 空载电流impedance 阻抗positive sequence impedance正序阻抗negative sequence impedance 负序阻抗zero sequence impedance零序阻抗susceptance 电纳stator 定子high voltage 高压fixed series capacitor compensation固定串联电容补偿voltage stability 电压稳定angle stability 功角稳定installed capacity 装机容量transformer substation 变电站degree of compensation 补偿度line drop compensation（LDC）线路补偿器circuit theorems 电路定理superposition theorem 叠加定理substitution theorem 替代定理thevenin-Norton Theorem 戴维宁定理electromagnetism 电磁; 电磁学low-frequency amplifier 低频放大器low-frequency bypass 低频旁路voltage distortion 交流电压校准器Single Chip Microprocessor(SCM)单片机alternating current(AC) 交流/交流电adjustable pressure conveyor 调压输送机allowable load impedance 允许的负载阻抗closed loop control 闭环控制closed loop voltage gain 闭环电压增益closed-loop gain 死循环增益clutch 离合器/联轴器commutator/rectifier 整流器cut off voltage 临界电压cut-in voltage 闭合电压dielectric adj. 不导电的/绝缘的dielectric puncture 击穿electrical durability 电寿命（万次）electromagnetic resonance 电磁感应electromotive force 电动力/电动势positive charge 正电荷negative charge 负电荷Automatic Generation Control(AGC) 自动发电控制Power System Stabilizator(PSS) 电力系统稳定器polyphase 多相(的)iron-loss 铁损armature circuit 电枢电路dynamic response 动态响应time invariant adj.时不变的self-inductor 自感mutual-inductor 互感polarity 极性ventilation 通风，换气，通风装置interface 接口demodulator 解调器balance indicator 交流平衡指示器current calibrator 交流电流校准器resistance box 交流电阻箱voltage distortion 交流电压校准器standard resistor 交流标准电阻器low-frequency bypass 低频旁路power pool 联合电力系统；联合电网electromagnetism 电磁; 电磁学core/shell forme 铁心式/壳式potential difference 电位差dual in-line packages 双列直插式组件automatic control system 自动控制系统torque motor 力矩电动机amplifier using discrete 分离元件放大器potentiometer 电位器voltage-current characteristic 伏安特性topology 拓扑termocouple 热电偶exitation 激发;激励;干扰air-gap 气隙polyphase n.多相adj. 多相的breakdown torque 失步转矩locked-rotor torque 止转转矩nominal frequency 额定频率subtransmission 二次输电hydro-generation 水力发电feeder 馈线;馈电电路thermal unit 热力机组active power balance 有功功率平衡load-frequency control（LFC）负荷频率控制sychronous condenser 同步调相机tap-changing transformer 可调分接头变压器tap coil 跳闸线圈magnetic air circuit breaker 磁吹断路器automatic generation control （AGC）自动发电控制circuit board 电路板direct current（DC）直流电eddy current 涡流corridor 通路induced current 感生电流laminated core 叠片铁芯left-hand rule 左手定则volt-ampere characteristics 伏安特性simulation analysis 仿真分析one machine - infinity bus system 单机无穷大系统Electrical Machinery电机学Automatic Control Theory自动控制理论Electrotechnics Principle of Circuits 电工学Electrical Drive and Control电力传动与控制brownout 节约用电cathode 阴板、负极cation exchanger 阳离子交换器circuit breaker 电路断路器circuit diagram 电路图coaxial cable 同轴电缆cooling tower 冷却塔intermediate relay 中间继电器jumper 跳线、跨接lightning arrestor 避雷器installed capacity 装机容量instrument panel 仪表盘instantaneous power 瞬时功率loss of excitation 励磁损失manual reject 手动切换overhead line 架空线plant load factor 电厂负荷因数potential transformer电压互感器overspeed trip 超速跳闸pyod 热电偶safe potential 安全电压shield 屏蔽层single blade switch单刀开关star connected system星形连接制"Y" static storage 静态存储器station capacity 发电厂容量step-down transformer降压变压器substation 变电站、子站subtransmission 二次输电thermal power plant 热力发电厂thumb rule 安培右手定则trip 跳闸、断开star connected system星形连接制"Y"A/C adaptor 电源适配器analog to digital 模拟/数字转换ac induced polarization instrument 交流激电仪adjustable pressure conveyor 调压输送机allowable load impedance 允许的负载阻抗charge neutrality 电中性区Charge Termination Voltage 允电端电压/允电端接电压circuit diagram 电路板circuit switching 电路交换closed-loop voltage gain 死循环电压增益connectors 插接器constant voltage modulation 稳压调节current attenuation 电流减衰装置Current by Phase (AMP) 每相电流current limitative range 电流限制范围cut off voltage 临界电压cut-in voltage 闭合电压Discharge Termination Voltage 放电端电压dropout voltage 跌落电压eddy current 涡电流electormagnetic braking sytem 电磁制动系统electric dipole 电偶极子electric shielding 电屏蔽Frequency Hopping 跳频input-output control system (IOCS) 输入输出控制系统offset voltage 失调电压。
电气英语翻译专业词汇
电⽓英语翻译专业词汇电⽓⼯程词汇voltage 电压current 电流resistance 电阻reactance 电抗impedance 阻抗conductance 电导inductance 电感inductor 电感器capacitance 电容capacitive 电容性的，电容的shunt capacitor 并联电容器shunt 并联series 串联series circuit 串联电路parallel circuit 并联电路conductor 导线voltmeter 电压表ammeter 电流表arc 电弧charge n 电荷v充电，带电，起电discharge v 放电bridge 电桥valve 电⼦管deenergize 断路dielectric 不导电的/绝缘的generator 发电机motor 电动机audion 三极管diode ⼆极管potentiometer 电位器step-up transformer 升压变压器power system 电⼒系统,电⽹transmission line 输电线breaker 断路器relay 继电器demodulator 解调器radiator 散热器ventilation 通风，换⽓，通风装置alternating relay 交流继电器integrated circuit amplifier 集成电路放⼤器transistor amplifier 晶体管放⼤器terminal 端⼦amplifier/magnifier 放⼤器cable n 电缆v架设电缆fuse 保险丝熔断器interface 接⼝amplitude 振幅幅度波幅digital signal 数字信号coupling 耦合intermittent 周期的dislocation 错位malfunction 故障medium 介质screen 屏蔽dampen 阻尼socket 插孔ground plane 接地层three-phasen 三相potential difference 电位差active element 有源元件ideal independent source 理想独⽴电源watt hour meter 感应线圈frequency changer 变频器control switch 控制开关selector switch 选择开关current transformer 电流互感器power transformer 电⼒变压器phase voltage 相电压constant voltage source 恒定电压源alternating current 交流电流inverting 反相out of phase 异相self-inductor ⾃感mutual-inductor 互感ampere 安培coulomb 库仑joule 焦⽿resistor 电阻器charger 充电器semiconductor 半导体absolute value 绝对值operating supply voltage 电源⼯作电压专业词汇Isolator ⼑闸(隔离开关) Susceptance 电纳regulator 稳压器admittance 导纳rectifier 整流器busbar 母线analog signal 模拟信号asynchronism 异步synchronization 同步armature 电枢attenuate 衰减steam-turbine-driven generator ⽓轮发电机turbine generator 涡轮发电机magnetic flux 磁通量oscilloscope ⽰波器oscillator 震荡器multimeter 万⽤表overlay 叠加效果rated power 额定功率power amplifier 功率放⼤器active voltage 有效电压voltage to current converter 电压电流变换器transformer substation变电站regulation 调节degree of compensation补偿度high voltage shunt reactor⾼抗reactive power compensation⽆功补偿three-column transformer三绕组变压器double-column transformer双绕组变压器power-factor 功率因数voltage grade 电压等级no-load current 空载电流impedance 阻抗positive sequence impedance正序阻抗negative sequence impedance 负序阻抗zero sequence impedance零序阻抗susceptance 电纳stator 定⼦high voltage ⾼压fixed series capacitor compensation固定串联电容补偿voltage stability 电压稳定angle stability 功⾓稳定installed capacity 装机容量transformer substation 变电站degree of compensation 补偿度line drop compensation（LDC）线路补偿器circuit theorems 电路定理superposition theorem 叠加定理substitution theorem 替代定理thevenin-Norton Theorem 戴维宁定理electromagnetism 电磁; 电磁学low-frequency amplifier 低频放⼤器low-frequency bypass 低频旁路voltage distortion 交流电压校准器Single Chip Microprocessor(SCM)单⽚机alternating current(AC) 交流/交流电adjustable pressure conveyor 调压输送机allowable load impedance 允许的负载阻抗closed loop control 闭环控制closed loop voltage gain 闭环电压增益closed-loop gain 死循环增益clutch 离合器/联轴器commutator/rectifier 整流器cut off voltage 临界电压cut-in voltage 闭合电压dielectric adj. 不导电的/绝缘的dielectric puncture 击穿electrical durability 电寿命（万次）electromagnetic resonance 电磁感应electromotive force 电动⼒/电动势positive charge 正电荷negative charge 负电荷Automatic Generation Control(AGC) ⾃动发电控制Power System Stabilizator(PSS) 电⼒系统稳定器polyphase 多相(的)iron-loss 铁损armature circuit 电枢电路dynamic response 动态响应time invariant adj.时不变的self-inductor ⾃感mutual-inductor 互感polarity 极性ventilation 通风，换⽓，通风装置interface 接⼝demodulator 解调器balance indicator 交流平衡指⽰器current calibrator 交流电流校准器resistance box 交流电阻箱voltage distortion 交流电压校准器standard resistor 交流标准电阻器low-frequency bypass 低频旁路power pool 联合电⼒系统；联合电⽹electromagnetism 电磁; 电磁学core/shell forme 铁⼼式/壳式potential difference 电位差dual in-line packages 双列直插式组件automatic control system ⾃动控制系统torque motor ⼒矩电动机amplifier using discrete 分离元件放⼤器potentiometer 电位器voltage-current characteristic 伏安特性topology 拓扑termocouple 热电偶exitation 激发;激励;⼲扰air-gap ⽓隙polyphase n.多相adj. 多相的breakdown torque 失步转矩locked-rotor torque ⽌转转矩nominal frequency 额定频率subtransmission ⼆次输电hydro-generation ⽔⼒发电feeder 馈线;馈电电路thermal unit 热⼒机组active power balance 有功功率平衡load-frequency control（LFC）负荷频率控制sychronous condenser 同步调相机tap-changing transformer 可调分接头变压器tap coil 跳闸线圈magnetic air circuit breaker 磁吹断路器automatic generation control （AGC）⾃动发电控制circuit board 电路板direct current（DC）直流电eddy current 涡流corridor 通路induced current 感⽣电流laminated core 叠⽚铁芯left-hand rule 左⼿定则volt-ampere characteristics 伏安特性simulation analysis 仿真分析one machine - infinity bus system 单机⽆穷⼤系统Electrical Machinery电机学Automatic Control Theory⾃动控制理论Electrotechnics Principle of Circuits 电⼯学Electrical Drive and Control电⼒传动与控制brownout 节约⽤电cathode 阴板、负极cation exchanger 阳离⼦交换器circuit breaker 电路断路器circuit diagram 电路图coaxial cable 同轴电缆cooling tower 冷却塔intermediate relay 中间继电器jumper 跳线、跨接lightning arrestor 避雷器installed capacity 装机容量instrument panel 仪表盘instantaneous power 瞬时功率loss of excitation 励磁损失manual reject ⼿动切换overhead line 架空线plant load factor 电⼚负荷因数potential transformer电压互感器overspeed trip 超速跳闸pyod 热电偶safe potential 安全电压shield 屏蔽层single blade switch单⼑开关star connected system星形连接制"Y" static storage 静态存储器station capacity 发电⼚容量step-down transformer降压变压器substation 变电站、⼦站subtransmission ⼆次输电thermal power plant 热⼒发电⼚thumb rule 安培右⼿定则trip 跳闸、断开star connected system星形连接制"Y"A/C adaptor 电源适配器analog to digital 模拟/数字转换ac induced polarization instrument 交流激电仪adjustable pressure conveyor 调压输送机allowable load impedance 允许的负载阻抗charge neutrality 电中性区Charge Termination Voltage 允电端电压/允电端接电压circuit diagram 电路板circuit switching 电路交换closed-loop voltage gain 死循环电压增益connectors 插接器constant voltage modulation 稳压调节current attenuation 电流减衰装置Current by Phase (AMP) 每相电流current limitative range 电流限制范围cut off voltage 临界电压cut-in voltage 闭合电压Discharge Termination Voltage 放电端电压dropout voltage 跌落电压eddy current 涡电流electormagnetic braking sytem 电磁制动系统electric dipole 电偶极⼦electric shielding 电屏蔽Frequency Hopping 跳频input-output control system (IOCS) 输⼊输出控制系统offset voltage 失调电压。
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式中p是以瓦特为单位的功率，w是以焦耳为 单位的能量，t是以秒为单位的时间，从方程（ 1－1）、（1－3）和（1－5）可以推出
p ui
由于u和i通常是时间的函数，方程（1－6）中的 功率p是个时间变量于是被称为瞬时功率，某一元件 吸收或提供的功率等于元件两端电压和通过它的电流 的乘积。如果这个功率的符号是正的，那么功率向元 件释放或被元件吸收。另一方面，如果功率的符号是 负的，那么功率是由元件提供的。但我们如何得知何 时功率为正或为负？
独立源
一个理想的独立源是产生完全独立于其它电 路变量的特定电压或电流的有源元件。一个独 立电压源是一个二端口元件，如一个电池或一 台发电机，它们在其端部维持某个特定的电压 。该电压完全独立于流过元件的电流，在其端 部具有u伏电压的电压源的符号如图1－4（a） 所示，极性如图所示，它表明a端比b端高u伏 。如果u>0，那么a端的电位高于b端，当然， 如果u<0，反之亦然。
一个独立电流源是二端元件在两端之 间特定的电流流过，该电流完全独立于元 件两端的电压，一个独立电流源的符合如 图1－5所示。图中i是特定电流，该电流的 方向由箭头标明。
独立源通常指的是向外电路释放功率而非吸 收功率，因此如果u是电源两端的电压而电流i直 接从其正端流出，那么该电源正在向对电路释放 功率，由式p＝ui算出。否则它就在吸收功率。例 如图1－6（a）中电池正在向外电路释放功率 24w，在图1－6（b）中，电池就在充电情况， 吸收功率24w。
在图1－4（a）中，电压u可以是随时间而变 化，或者可以是恒定的，在这种情况下我们可能 把它标为U，对于恒定电压源我们通常使用另一种 符号，例如在两端只有U伏电压的电池图1－4（a）或图1－4（b）。
我们可能已经注意到这一点，即图1－4 （b）中的极性标号，是多余的因为我们可以 根据长天线的位置符，确定电池极性。
呈现电中性。
让我们来考虑一下电荷的流动。电荷或电的特性
是其运动的特性，也就是，它可以从一个地方被移送到 另一个地方，在此它可以被转换成另外一种形式的能量 。
当我们把一根导线连接到某一电池上时(一种电动 势源)，电荷被外力驱使移动；正电荷朝一个方向移动 而负电荷朝相反的方向移动。这种电荷的移动产生了电 流。我们可以很方便地把电流看作是正电荷的移动，也 即，与负电荷的流动方向相反，如图1－1所示。这一 惯例是由美国科学家和发明家本杰明－富兰克林引入的 。虽然我们现在知道金属导体中的电流是由负电荷引起 的，但我们将遵循通用的惯例，即把电流看作是正电荷 的单纯的流动。于是电流就是电荷的时率，它是以安培 为单位来度量的。从数学上来说，电流i、电荷q以及时 间t之间的关系是：
在我们确定功率符号时，电流的方向和电压的极性起 着主要的作用，这就是我们在分析图1－3（a）所显示 的电流i和电压u的关系时特别谨慎的重要原因。为了使 功率的符号为正，电压的极性和电流的方向必须与图1－ 3（a）所示的一致。
这种情况被称为无源符号惯例，对于无源符号惯 例来说，电流流进电压的正极。在这种情况下，p＝ui 或ui>0，表明元件是在吸收功率。而如果p＝－ui或 ui<0，如图1－3（b）所示时，表明元件是在释放或 提供功率。
图1－2显示了某个元件（用一个矩形框来表示） 两端a、b之间的电压。正号（＋）和负号（－）被用 来指明参考方向或电压的极性，Uab可以通过以下两种 方法来解释。1）在Uab伏特的电位中a点电位高于b点 ，2）a点电位相对于b点而言是Uab，通常在逻辑上遵 循
uab -uba
虽然电流和电压是电路的两个基本变量，但仅有 它们两个是不够的。从实际应用来说，我们需要知道功 率和能量。为了把功率和能量同电压、电流联系起来， 我们重温物理学中关于功率是消耗或吸收的能量的时率 ，它是以瓦特为单位来度量的。我们把这个关系式写成 ：
i dq dt
从时间t0到时间t所移送的电荷可由方程（1－1）两 边积分求得。我们算得：
t
q idt t0
我们通过方程（1－1）定义电流的方式表明电流 不必是一个恒值函数，电荷可以不同的方式随时间 而变化，这些不同的方式可用各种数学函数表达出 来。
电压，能量和功率 在导体中朝一个特定的方向移动电荷需要一些功
第一节 电流和电压
u(t)和i(t)这两个变量是电路中最基本的两个变量 ，它们刻划了电路的各种关系。
电荷和电流 电荷的概念是用来解释所有电气现象的基本概念 。也即，电路中最基本的量是电荷。电荷是构成物质 的原子微粒的电气属性，它是以库仑为单位来度量的 。 我们从基础物理得知一切物质是由被称为原子的 基本构造部分组成的，并且每个原子是由电子，质子 和中子组成的。我们还知道电子的电量是负的并且在 数值上等于1.602100×10-12C，而质子所带的正电量 在数值上与电子相等。质子和电子数量相同使得原子
或者能量的传递，这个功是由外部的电动势来完成的 。图1－1所示的电池就是一个典型的例子。这种电动 势也被称为电压或电位差。电路中a、b两点间的电压 等于从a到b移动单位电荷所需的能量（或所需做的功 ）。数学表达式为：
uab
dw dq
式中w是单位为焦耳的能量而q是单位为库仑的电荷。 电压Uab是以伏特为单位来度量的，它是为了纪念意大 利物理学家Alessandro Antonio Volta而命名的，这位意 大利物理学家发明了首个伏达电池。于是电压（或电压 差）等于将单位电荷在元件中移动所需的能量，它是以 伏特为单位来度量的。
事实上，在任何电路中必须遵循能量守恒定律。 由于这个原因，任一电路中在任何瞬间功率的代数和 必须等于零
p 0
这再一次证明了提供给电路的功率必须与吸收 的功率相平衡这一事实。从方程（1－7）可知，从 时间t0到时间t被元件吸收或由元件提供的功率等于
t
w pdt t0
第二节 电路元件
电路仅仅是元件之间的相互结合。我 们发现电路中存在有两种元件：无源元件 和有源元件。有源元件能够产生能量而无 源元件却不能，无源元件有电阻、电容和 电感器等。最重要的有源元件是通常向与 它们相连的电路释放能量的电压和电流源。