毕业设计三相异步电动机外文翻译
三相异步交流电机毕业设计书[管理资料]
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学生毕业设计（毕业论文）系别：机电工程专业：数控技术班级：学生姓名：学生学号：设计（论文）题目：三相异步交流电机指导教师：设计地点：起迄日期：毕业设计（论文）任务书专业班级姓名一、课题名称：三相异步电机的设计二、主要技术指标：1.内部由定子和转子构成。
2. 外壳有机座、端盖、轴承盖、接线盒、吊环等组成。
3. 技术要求：采用电压AC380，可以实现正反转。
三、工作内容和要求：1．设计磁路部分：定子铁心和转子铁心。
2 设计电路部分：定子绕组和转子绕组以及电路图。
3 设计机械部分：机座、端子、轴和轴承等。
4．设计电路的正反转和安全控制部分。
5．按照“毕业设计规格”设计毕业报告。
四、主要参考文献：1.[1]王世琨.《图解电工入门》[M]..2.[2]满永奎.《电工学》[M]..3.[3]乔长君.《电机绕组接线图册》[M]..学生（签名）年月日指导教师（签名）年月日教研室主任（签名）年月日系主任（签名）年月日毕业设计（论文）开题报告摘要在费拉里斯和特斯拉发明多相交流系统后，19世纪80年代中期，多沃罗沃尔斯基发明了三相异步电机，异步电机无需电刷和换向器三相异步电机(Triple-phase asynchronous motor)是靠同时接入380V三相交流电源（相位差120度）供电的一类电动机，由于三相异步电机的转子与定子旋转磁场以相同的方向、不同的转速成旋转，存在转差率，所以叫三相异步电机。
作电动机运行的三相异步电机。
三相异步电动机转子的转速低于旋转磁场的转速，转子绕组因与磁场间存在着相对运动而感生电动势和电流，并与磁场相互作用产生电磁转矩，实现能量变换。
与单相异步电动机相比，三相异步电动机运行性能好，并可节省各种材料。
按转子结构的不同，三相异步电动机可分为笼式和绕线式两种。
笼式转子的异步电动机结构简单、运行可靠、重量轻、价格便宜，得到了广泛的应用。
Reese and Tesla invented in AC system. At the mid of 1880s, 多沃罗沃尔Chomsky invented the three-phase asynchronous motors, asynchronous motors without brushes and commutate. Three-phase asynchronous motors (Triple-phase asynchronous motor) is by simultaneously accessing 380V three-phase AC power supply of a class of motors, three-phase asynchronous motor as the rotor and the stator rotating in the same direction, to rotate at different speeds, there turn slip, so called three-phase asynchronous motors.For three-phase asynchronous motors motor is running. Three-phase asynchronous motor rotor speed is lower than the speed of the rotating magnetic field, the magnetic field due to the rotor windings relative motion exists between the induced electromotive force and current, and the magnetic field generated by the interaction with the electromagnetic torque and achieve energy conversion. Compared with single-phase induction motor, Three- phase asynchronous motor running properties, and save a variety of materials. According to the different structure of the rotor, three-phase cage induction motor and the winding can be divided into two kinds. Cage rotor induction motor, simple structure, reliable operation, light weight, cheap, has been widely used目录摘要 (5)第一章电机的分类 (20)按电源分类 (21)按结构及工作原理 (25)按启动与运行方式 (30)按用途分类 (33)按转子的结构 (35)按转速分类 (30)第二章三相异步电机的概述简单介绍 (30)工作原理 (30)电机的参数 (30)启动与运行 (30)第三章三相异步电机的结构磁路部分的结构 (30)电路部分的结构 (30)机械部分的结构 (30)第四章电机的控制电路电机的正反转控制 (30)电机的调速控制 (30)斯沃软件的功能概括 (30)利用仿真软件模拟点动控制 (30)利用仿真软件模拟自锁正反转控制 (30)第五章三相异步电机的特点 (30)第六章致谢参考文献第一章电机的分类按电源分类按工作电源根据电动机工作电源的不同，可分为直流电动机和交流电动机。
(完整版)PLC毕业设计的外文文献(及翻译)
PLC technique discussion and future developmentT.J.byersElectronic Test Equipment-principles and ApplicationsPrinceton University .AmericaAlong with the development of the ages, the technique that is nowadays is also gradually perfect, the competition plays more strong; the operation that list depends the artificial has already can't satisfied with the current manufacturing industry foreground, also can't guarantee the request of the higher quantity and high new the image of the technique business enterprise.The people see in produce practice, automate brought the tremendous convenience and the product quantities for people up of assurance, also eased the personnel's labor strength, reduce the establishment on the personnel. The target control of the hard realization in many complicated production lines, whole and excellent turn, the best decision etc, well-trained operation work, technical personnel or expert, governor but can judge and operate easily, can acquire the satisfied result. The research target of the artificial intelligence makes use of the calculator exactly to carry out, imitate these intelligences behavior, moderating the work through person's brain and calculators, with the mode that person's machine combine, for resolve the very complicated problem to look for the best path.We come in sight of the control that links after the electric appliances in various situation, that is already the that time generation past, now of after use in the mold a perhaps simple equipments of grass-roots control that the electric appliances can do for the low level only; And the PLC emergence also became the epoch-making topic, adding the vivid software control through a very and stable hardware, making the automation head for the new high tide.The PLC biggest characteristics lie in: The electrical engineering teacher already no longer electric hardware up too many calculations of cost, as long as order the importation that the button switch or the importation of the sensors order to link the PLC up can solve problem, pass to output to order the conjunction contact machine or control the start equipments of the big power after the electric appliances, but the exportation equipmentsdirect conjunction of the small power can.PLC internal containment have the CPU of the CPU, and take to have an I/ O for expand of exterior to connect a people's address and saving machine three big pieces to constitute, CPU core is from an or many is tired to add the machine to constitute, mathematics that they have the logic operation ability, and can read the procedure save the contents of the machine to drive the homologous saving machine and I/ Os to connect after pass the calculation; The I/ O add inner part is tired the input and output system of the machine and exterior link, and deposit the related data into the procedure saving machine or data saving machine; The saving machine can deposit the data that the I/ O input in the saving machine, and in work adjusting to become tired to add the machine and I/ Os to connect, saving machine separately saving machine RAM of the procedure saving machine ROM and dates, the ROM can do deposit of the data permanence in the saving machine, but RAM only for the CPU computes the temporary calculation usage of hour of buffer space.The PLC anti- interference is very and excellent, our root need not concern its service life and the work situation bad, these all problems have already no longer become the topic that we fail, but stay to our is a concern to come to internal resources of make use of the PLC to strengthen the control ability of the equipments for us, make our equipments more gentle.PLC language is not we imagine of edit collected materials the language or language of Cs to carry on weaving the distance, but the trapezoid diagram that the adoption is original after the electric appliances to control, make the electrical engineering teacher while weaving to write the procedure very easy comprehended the PLC language, and a lot of non- electricity professional also very quickly know and go deep into to the PLC.Is PLC one of the advantage above and only, this is also one part that the people comprehend more and easily, in a lot of equipments, the people have already no longer hoped to see too many control buttons, they damage not only and easily and produce the artificial error easiest, small is not a main error perhaps you can still accept; But lead even is a fatal error greatly is what we can't is tolerant of. New technique always for bringing more safe and convenient operation for us, make we a lot of problems for face on sweep but light, do you understand the HMI? Says the HMI here you basically not clear what it is, also have no interest understanding, change one inside text explains it into the touch to hold orman-machine interface you knew, it combines with the PLC to our larger space.HMI the control not only is reduced the control press button, increase the vivid of the control, more main of it is can sequence of, and at can the change data input to output the feedback with data, control in the temperature curve of imitate but also can keep the manifestation of view to come out. And can write the function help procedure through a plait to provide the help of various what lies in one's power, the one who make operate reduces the otiose error. Currently the HMI factory is also more and more, the function is also more and more strong, the price is also more and more low, and the noodles of the usage are wide more and more. The HMI foreground can say that think to be good.At a lot of situations, the list is a smooth movement that can't guarantee the equipments by the control of the single machine, but pass the information exchanges of the equipments and equipments to attain the result that we want. For example fore pack and the examination of the empress work preface, we will arrive wrapping information feedback to examine the place, and examine the information of the place to also want the feedback to packing. Pass the information share thus to make both the chain connect, becoming a total body, the match of your that thus make is more close, at each other attain to reflect the result that mutually flick.The PLC correspondence has already come more body now its value, at the PLC and correspondence between Places, can pass the communication of the information and the share of the data’s to guarantee that of the equipments moderates mutually, the result that arrive already to repair with each other. Data conversion the adoption RS232 between PLC connect to come to the transmission data, but the RS232 pick up a people and can guarantee 10 meters only of deliver the distance, if in the distance of 1000 meters we can pass the RS485 to carry on the correspondence, the longer distance can pass the MODEL only to carry on deliver.The PLC data transmission is just to be called a form to it in a piece of and continuous address that the data of the inner part delivers the other party, we, the PLC of the other party passes to read data in the watch to carry on the operation. If the data that data in the watch is a to establish generally, that is just the general data transmission, for example today of oil price rise, I want to deliver the price of the oil price to lose the oil ally on board, that is the share of the data; But take data in the watch for an instruction procedure that controls the PLC, that had the difficulty very much, for example you have to control one pedestal robot to pressthe action work that you imagine, you will draw up for it the form that a procedure combine with the data sends out to pass by.The form that information transport contain single work, the half a work and the difference of a workers .The meaning of the single work also is to say both, a can send out only, but a can receive only, for example a spy he can receive the designation of the superior only, but can't give the superior reply; A work of half is also 2 and can send out similar to accept the data, but can't send out and accept at the same time, for example when you make a phone call is to can't answer the phone, the other party also; But whole pair works is both can send out and accept the data, and can send out and accept at the same time. Be like the Internet is a typical example.The process that information transport also has synchronous and different step cent: The data line and the clock lines are synchronous when synchronous meaning lie in sending out the data, is also the data signal and the clock signals to be carry on by the CPU to send out at the same time, this needs to all want the specialized clock signal each other to carry on the transmission and connect to send, and is constrained, the characteristics of this kind of method lies in its speed very quick, but correspond work time of take up the CPU and also want to be long oppositely, at the same time the technique difficulty also very big. Its request lies in canting have an error margins in a dates deliver, otherwise the whole piece according to compare the occurrence mistake, this on the hardware is a bigger difficulty. Applied more and more extensive in some appropriative equipments, be like the appropriative medical treatment equipments, the numerical signal equipments...etc., in compare the one data deliver, its result is very good.And the different step is an application the most extensive, this receive benefit in it of technique difficulty is opposite and want to be small, at the same time not need to prepare the specialized clock signal, its characteristics to lie in, its data is partition, the long-lost send out and accept, be the CPU is too busy of time can grind to a stop sex to work, also reduced the difficulty on the hardware, the data throw to lose at the same time opposite want to be little, we can pass the examination of the data to observe whether the data that we send out has the mistake or not, be like strange accidentally the method, tired addition and eight efficacies method etc, can use to helps whether the data that we examine to send out have or not themistake occurrence, pass the feedback to carry on the discriminator.A line of transmission of the information contains a string of and combines the cent of: The usual PLC is 8 machines, certainly also having 16 machines. We can be at the time of sending out the data a send out to the other party, also can be 88 send out the data to the other party, and 8 differentiations are also the as that we say to send out the data and combine sends out the data. A speed is more and slowly, but as long as 2 or three lines can solve problem, and can use the telephone line to carry on the long range control. But combine the ocular transmission speed is very quick of, it is a string of ocular of 25600%, occupy the advantage in the short distance, the in view of the fact TTL electricity is even, being limited by the scope of one meter generally, it combine unwell used for the data transmission of the long pull, thus the cost is too expensive.Under a lot of circumstances we are total to like to adopt the string to combine the conversion chip to carry on deliver, under this kind of circumstance not need us to carry on to deposited the machine to establish too and complicatedly, but carry on the data exchanges through the data transmission instruction directly, but is not a very viable way in the correspondence, because the PLC of the other party must has been wait for your data exportation at the time of sending out the data, it can't do other works.When you are reading the book, you hear someone knock on door, you stop to start up of affair, open the door and combine to continue with the one who knock on door a dialogue, the telephone of this time rang, you signal hint to connect a telephone, after connecting the telephone through, return overdo come together knock on door to have a conversation, after dialogue complete, you continue again to see your book, this kind of circumstance we are called the interruption to it, it has the authority, also having sex of have the initiative, the PLC had such function .Its characteristics lie in us and may meet the urgently abrupt affairs in the operation process of the equipments, we want to stop to start immediately up of work, the whereabouts manages the more important affair, this kind of circumstance is we usually meet of, PLC while carry out urgent mission, total will keep the current appearance first, for example the address of the procedure, CPU of tired add the machine data etc., be like to stick down which the book that we see is when we open the door the page or simply make a mark, because we treat and would still need to continue immediately after book of see the behind.The CPU always does the affair that should do according to our will, but your mistake of give it an affair, it also would be same to do, this we must notice.The interruption is not only a, sometimes existing jointly with the hour several inside break, break off to have the preferred Class, they will carry out the interruption of the higher Class according to person's request. This kind of breaks off the medium interruption to also became to break off the set. The Class that certainly breaks off is relevant according to various resources of CPU with internal PLC; also following a heap of capacity size of also relevant fasten.The contents that break off has a lot of kinds, for example the exterior break off, correspondence in of send out and accept the interruption and settle and the clock that count break off, still have the WDT to reset the interruption etc., they enriched the CPU to respond to the category while handle various business. Speak thus perhaps you can't comprehend the internal structure and operation orders of the interruption completely also, we do a very small example to explain.Each equipment always will not forget a button, it also is at we meet the urgent circumstance use of that is nasty to stop the button. When we meet the Human body trouble and surprised circumstances we as long as press it, the machine stops all operations immediately, and wait for processing the over surprised empress recover the operation again. Nasty stop the internal I/ O of the internal CPU of the button conjunction PLC to connect up, be to press button an exterior to trigger signal for CPU, the CPU carries on to the I/ O to examine again, being to confirm to have the exterior to trigger the signal, CPU protection the spot breaks off procedure counts the machine turn the homologous exterior I/ O automatically in the procedure to go to also, be exterior interruption procedure processing complete, the procedure counts the machine to return the main procedure to continue to work. Have 1:00 can what to explain is we generally would nasty stop the button of exterior break off to rise to the tallest Class, thus guarantee the safety.When we are work a work piece, giving the PLC a signal, counting PLC inner part the machine add 1 to compute us for a day of workload, a count the machine and can solve problem in brief, certainly they also can keep the data under the condition of dropping the electricity, urging the data not to throw to lose, this is also what we hope earnestly.The PLC still has the function that the high class counts the machine, being us while accept some dates of high speed, the high speed that here say is the data of the in all aspects tiny second class, for example the bar code scanner is scanning the data continuously, calculating high-speed signal of the data processor DSP etc., we will adopt the high class to count the machine to help we carry on count. It at the PLC carries out the procedure once discover that the high class counts the machine to should of interruption, will let go of the work on the hand immediately. The trapezoid diagram procedure that passes by to weave the distance again explains the high class for us to carry out procedure to count machine would automatic performance to should of work, thus rise the Class that the high class counts the machine to high one Class.You heard too many this phrases perhaps:" crash", the meaning that is mostly is a workload of CPU to lead greatly, the internal resources shortage etc. the circumstance can't result in procedure circulate. The PLC also has the similar circumstance, there is a watchdog WDT in the inner part of PLC, we can establish time that a procedure of WDT circulate, being to appear the procedure to jump to turn the mistake in the procedure movement process or the procedure is busy, movement time of the procedure exceeds WDT constitution time, the CPU turn but the WDT reset the appearance. The procedure restarts the movement, but will not carry on the breakage to the interruption.The PLC development has already entered for network ages of correspondence from the mode of the one, and together other works control the net plank and I/ O card planks to carry on the share easily. A state software can pass all se hardwires link, more animation picture of keep the view to carries on the control, and cans pass the Internet to carry on the control in the foreign land, the blast-off that is like the absolute being boat No.5 is to adopt this kind of way to make airship go up the sky.The development of the higher layer needs our continuous effort to obtain. The PLC emergence has already affected a few persons fully, we also obtained more knowledge and precepts from the top one experience of the generation, coming to the continuous development PLC technique, push it toward higher wave tide.可编程控制器技术讨论与未来发展T.J.拜尔斯（电子测试设备原理及应用普林斯顿大学）随着时代的发展，当今的技术也日趋完善、竞争愈演愈烈；单靠人工的操作已不能满足于目前的制造业前景，也无法保证更高质量的要求和高新技术企业的形象。
三相异步变频电机 英语
三相异步变频电机英语Three-phase Asynchronous Variable Frequency Motor.Introduction.In the realm of electrical engineering, motors play a pivotal role in converting electrical energy into mechanical energy. Among various types of motors, three-phase asynchronous variable frequency motors have emerged as a popular choice due to their efficiency, reliability, and adaptability. These motors are widely used in industrial applications, including pumps, fans, conveyors, and other mechanical systems.Working Principle.A three-phase asynchronous motor operates on the principle of electromagnetic induction. It consists of a stator and a rotor. The stator, which is stationary, has windings that are supplied with three-phase alternatingcurrent (AC). The rotor, on the other hand, rotates inside the stator.When the three-phase AC supply is given to the stator windings, it creates a rotating magnetic field. Thisrotating magnetic field induces currents in the rotor conductors, which in turn produce their own magnetic fields. The interaction between the stator's rotating magneticfield and the rotor's magnetic fields causes the rotor to rotate.The rotor's speed, however, is slightly less than the synchronous speed of the rotating magnetic field. Thisspeed difference is due to the slip between the rotor and the stator, hence the term "asynchronous".Variable Frequency Control.The frequency of the AC supply to the motor can be varied, allowing for precise control over the motor's speed and torque. Variable frequency control is achieved through the use of a variable frequency drive (VFD) or an inverter.A VFD converts the fixed-frequency AC supply to a variable-frequency output, which can be adjusted as per the motor's requirements. By varying the frequency, the speed of the motor can be controlled. Additionally, the VFD can also control the voltage supplied to the motor, allowingfor further fine-tuning of the motor's performance.Variable frequency control offers several advantages.It enables precise speed control, improves energy efficiency, and reduces mechanical stress on the motor. It also allows for smoother acceleration and deceleration, enhancing the overall performance and reliability of the motor.Applications.Three-phase asynchronous variable frequency motors are widely used in various industrial applications. Some of the common applications include:1. Pumping Systems: These motors are commonly used inpumping systems to control the flow rate and pressure of fluids. By varying the motor's speed, the pump can be adjusted to meet the demand for water or other fluids.2. Fan Applications: In ventilation and cooling systems, variable frequency motors are used to control airflow. By adjusting the motor's speed, the fan can be optimized to maintain a comfortable indoor environment while minimizing energy consumption.3. Conveyor Systems: In material handling applications, conveyor systems often employ variable frequency motors. These motors allow for precise control over the conveyor's speed, ensuring efficient and smooth transportation of materials.4. Machine Tools: Machine tools such as lathes, milling machines, and grinding machines often utilize variable frequency motors for precise speed control and improved machining accuracy.Conclusion.Three-phase asynchronous variable frequency motors play a crucial role in modern industrial applications. Their ability to operate efficiently at variable speeds, combined with the precision control offered by variable frequency drives, makes them an ideal choice for a wide range of mechanical systems. With the increasing demand for energy-efficient and sustainable solutions, these motors are expected to find even more applications in the future.。
异步电动机外文文献翻译中英文
外文文献翻译(含：英文原文及中文译文)文献出处：Larabee J, Pellegrino B, Flick B. Induction motor starting methods and issues[C]// Petroleum and Chemical Industry Conference, 2005. Industry Applications Society. IEEE, 2005:217-222.译文：4600多字英文原文Induction motor starting methods and issuesJ Larabee ，B Pellegrino ，B FlickAbstract -Many methods can be used to start large AC induction motors. Choices such as full voltage, reduced voltage either by autotransformer or Wyes - Delta, a soft starter, or usage of an adjustable speed drive can all have potential advantages and trade offs. Reduced voltage starting can lower the starting torque and help prevent damage to the load. Additionally, power factor correction capacitors can be used to reduce the current, but care must be taken to size them properly. Usage of the wrong capacitors can lead to significant damage. Choosing the proper starting method for a motor will include an analysis of the power system as well as the starting load to ensure that the motor is designed to deliver the needed performance while minimizing its cost. This paper will examine the most common starting methods and their recommended applications.I. INTRODUCTIONThere are several general methods of starting induction motors: full voltage, reduced voltage, wyes-delta, and part winding types. The reduced voltage type can include solid state starters, adjustable frequency drives, and autotransformers. These, along with the full voltage, or across the line starting, give the purchaser a large variety of automotives when it comes to specifying the motor to be used in a given application. Each method has its own benefits, as well as performance trade offs. Proper selection will involve a thorough investigation of any power system constraints, the load to be accelerated and the overall cost of the equipment.In order for the load to be accelerated, the motor must generate greater torque than the load requirement. In general there are three points of interest on the motor's speed-torque curve. The first is locked-rotor torque (LRT) which is the minimum torque which the motor will develop at rest for all angular positions of the rotor. The second is pull-up torque (PUT) which is defined as the minimum torque developed by the motor during the period of acceleration from rest to the speed at which breakdown torque occurs. The last is the breakdown torque (BDT) which is defined as the maximum torque which the motor will develop. If any of these points are below the required load curve, then the motor will not start.The time it takes for the motor to accelerate the load is dependent onthe inertia of the load and the margin between the torque of the motor and the load curve, sometimes called accelerating torque. In general, the longer the time it takes for the motor to accelerate the load, the more heat that will be generated in the rotor bars, shorting ring and the stator winding. This heat leads to additional stresses in these parts and can have an impaction motor life.II. FULL VOL TAGEThe full voltage starting method, also known as across the line starting, is the easiest method to employ, has the lowest equipment costs, and is the most reliable. This method utilizes a control to close a contactor and apply full line voltage to the motor terminals. This method will allow the motor to generate its highest starting torque and provide the shortest acceleration times.This method also puts the highest strain on the power system due to the high starting currents that can be typically six to seven times the normal full load current of the motor. If the motor is on a weak power system, the sudden high power draw can cause a temporary voltage drop, not only at the motor terminals, but the entire power bus feeding the starting motor. This voltage drop will cause a drop in the starting torque of the motor, and a drop in the torque of any other motor running on the power bus. The torque developed by an induction motor varies roughly as the square of the applied voltage. Therefore, depending on the amount ofvoltage drop, motors running on this weak power bus could stall. In addition, many control systems monitor under voltage conditions, a second potential problem that could take a running motor offline during a full voltage start. Besides electrical variation of the power bus, a potential physical disadvantage of an across the line starting is the sudden loading seen by the driven equipment. This shock loading due to transient torques which can exceed 600% of the locked rotor torque can increase the wear on the equipment, or even cause a catastrophic failure if the load can not handle the torques generated by themotor during staring.A. Capacitors and StartingInduction motors typically have very low power factor during starting and as a result have very large reactive power draw. See Fig. 2. This effect on the system can be reduced by adding capacitors to the motor during starting.The large reactive currents required by the motor lag the applied voltage by 90 electrical degrees. This reactive power doesn't create any measurable output, but is rather the energy required for the motor to function. The product of the applied system voltage and this reactive power component can be measured in V ARS (volt-ampere reactive). The capacitors act to supply a current that leads the applied voltage by 90 electrical degrees. The leading currents supplied by the capacitors cancel the lagging current demanded by the motor, reducing the amount ofreactive power required to be drawn from the power system.To avoid over voltage and motor damage, great care should be used to make sure that the capacitors are removed as the motor reaches rated speed, or in the event of a loss of power so that the motor will not go into a generator mode with the magnetizing currents provided from the capacitors. This will be expanded on in the next section and in the appendix.B. Power Factor CorrectionCapacitors can also be left permanently connected to raise the full load power factor. When used in this manner they are called power factor correction capacitors. The capacitors should never be sized larger than the magnetizing current of the motor unless they can be disconnected from the motor in the event of a power loss.The addition of capacitors will change the effective open circuit time constant of the motor. The time constant indicates the time required for remaining voltage in the motor to decay to 36.8% of rated voltage after the loss of power. This is typically one to three seconds without capacitors.With capacitors connected to the leads of the motor, the capacitors can continue to supply magnetizing current after the power to the motor has been disconnected. This is indicated by a longer time constant for the system. If the motor is driving a high inertia load, the motor can changeover to generator action with the magnetizing Current from the capacitors and the shaft driven by the load. This can result in the voltage at the motor terminals actually rising to nearly 50% of rated voltage in some cases. If the power is reconnected before this voltage decays severe transients can be created which can cause significant switching currents and torques that can severely damage the motor and the driven equipment. An example of this phenomenon is outlined in the appendix.Current from the capacitors and the shaft driven by the load. This can result in the voltage at the motor terminals actually rising to nearly 50% of rated voltage in some cases. If the power is reconnected before this voltage decays severe transients can be created which can cause significant switching currents and torques that can severely damage the motor and the driven equipment. An example of this phenomenon is outlined in the appendix.Ⅲ. REDUCED VOL TAGEEach of the reduced voltage methods are intended to reduce the impact of motor starting current on the power system by controlling the voltage that the motor sees at the terminals. It is very important to know the characteristics of the load to be started when considering any form of reduced voltage starting. The motor manufacturer will need to have the speed torque curve and the inertia of the driven equipment when they validate their design. The curve can be built from an initial, or break awaytorque, as few as four other data points through the speed range, and the full speed torque for the starting condition. A centrifugal or square curve can be assumed in many cases, but there are some applications where this would be problematic. An example would be screw compressors which have a much higher torque requirement at lower speeds than the more common centrifugal or fan load. See Fig. 3. By understanding the details of the load to be started the manufacturer can make sure that the motor will be able to generate sufficient torque to start the load, with the starting method that is chosen.A. AutotransformerThe motor leads are connected to the lower voltage side of the transformer. The most common taps that are used are 80%, 65%, and 50%. At 50% voltage the current on the primary is 25% of the full voltage locked rotor amps. The motor is started with this reduced voltage, and then after a pre-set condition is reached the connection is switched to line voltage. This condition could be a preset time, current level, bus volts, or motor speed. The change over can be done in either a closed circuit transition, or an open circuit transition method. In the open circuit method the connection to the voltage is severed as it is changed from the reduced voltage to the line level. Care should be used to make sure that there will not be problems from transients due to the switching. This potential problem can be eliminated by using the closed circuit transition. With theclosed circuit method there is a continuous V oltage applied to the motor. Another benefit with the autotransformer starting is in possible lower vibration and noise levels during starting.Since the torque generated by the motor will vary as the square of the applied voltage, great care should be taken to make sure that there will be sufficient accelerating torque available from the motor. A speed torque curve for the driven equipment along with the inertia should be used to verify the design of the motor. A good rule of thumb is to have a minimum of 10% of the rated full load torque of the motor as a margin at all points of the curve.Additionally, the acceleration time should be evaluated to make sure that the motor has sufficient thermal capacity to handle the heat generated due to the longer acceleration time.B. Solid State or Soft StartingThese devices utilize silicon controlled rectifiers or Scars. By controlling the firing angle of the SCR the voltage that the device produces can be controlled during the starting of the motor by limiting the flow of power for only part of the duration of the sine wave.The most widely used type of soft starter is the current limiting type.A current limit of 175% to 500% of full load current is programmed in to the device. It then will ramp up the voltage applied to the motor until it reaches the limit value, and will then hold that current as the motoraccelerates.Tachometers can be used with solid state starters to control acceleration time. V oltage output is adjusted as required by the starter controller to provide a constant rate of acceleration.The same precautions in regards to starting torque should be followed for the soft starters as with the other reduced voltage starting methods. Another problem due to the firing angle of the SCR is that the motor could experience harmonic oscillating torques. Depending on the driven equipment, this could lead to exciting the natural frequency of the system.C. Adjustable Frequency DrivesThis type of device gives the greatest overall control and flexibility in starting induction motors giving the most torque for an amount of current. It is also the most costly.The drive varies not only the voltage level, but also the frequency, to allow the motor to operate on a constant volt per hertz level. This allows the motor to generate full load torque throughout a large speed range, up to 10:1. During starting, 150% of rated current is typical.This allows a significant reduction in the power required to start a load and reduces the heat generated in the motor, all of which add up to greater efficiency. Usage of the AFD also can allow a smaller motor to be applied due to the significant increase of torque available lower in thespeed range. The motor should still be sized larger than the required horsepower of the load to be driven. The AFD allows a great degree of control in the acceleration of the load that is not as readily available with the other types of reduced voltage starting methods.The greatest drawback of the AFD is in the cost relative to the other methods. Drives are the most costly to employ and may also require specific motor designs to be used. Based on the output signal of the drive, filtered or unfiltered, the motor could require additional construction features. These construction features include insulated bearings, shaft grounding brushes, and insulated couplings due to potential shaft current from common mode voltage. Without these features, shaft currents, which circulate through the shaft to the bearing, through the motor frame and back, create arcing in the bearings that lead to premature bearing failure, this potential for arcing needs to be considered when applying a motor/drive package in a hazardous environment, Division2/Zone2.An additional construction feature of a motor used on an AFD may require is an upgraded insulation system on the motor windings. An unfiltered output signal from a drive can create harmonic voltage spikes in the motor, stressing the insulation of the motor windings.It is important to note that the features described pertain to motors which will be started and run on an AFD. If the drive is only used for starting the motor, these features may not be necessary. Consult with themotor manufacturer for application specific requirements.D. Primary Resistor or Reactor StartingThis method uses either a series resistor or reactor bank to be placed in the circuit with the motor. Resistor starting is more frequently used for smaller motors.When the motor is started, the resistor bank limits the flow of inrush current and provides for a voltage drop at the motor terminals. The resistors can be selected to provide voltage reductions up to 50%. As the motor comes up to speed, it develops a counter EMF (electro-magnetic field) that opposes the voltage applied to the motor. This further limits the inrush currents. As the inrush current diminishes, so does t>e voltage drop across the resistor bank allowing the torque generated by the motor to increase. At a predetermined time a device will short across the resistors and open the starting contactor effectively removing the resistor bank from the circuit. This provides for a closed transition and eliminates the concerns due to switching transients.Reactors will tend to oppose any sudden changes in current and therefore act to limit the current during starting. They will remain shorted after starting and provide a closed transition to line voltage.E .Star delta StartingThis approach started with the induction motor, the structure of each phase of the terminal are placed in the motor terminal box. This allowsthe motor star connection in the initial startup, and then re-connected into a triangle run. The initial start time when the voltage is reduced to the original star connection, the starting current and starting torque by 2 / 3. Depending on the application, the motor switch to the triangle in the rotational speed of between 50% and the maximum speed. Must be noted that the same problems, including the previously mentioned switch method, if the open circuit method, the transition may be a transient problem. This method is often used in less than 600V motor, the rated voltage 2.3kV and higher are not suitable for star delta motor start method.Ⅴ. INCREMENT TYPEThe first starting types that we have discussed have deal with the way the energy is applied to the motor. The next type deals with different ways the motor can be physically changed to deal with starting issues.Part WindingWith this method the stator of the motor is designed in such a way that it is made up of two separate windings. The most common method is known as the half winding method. As the name suggests, the stator is made up of two identical balanced windings. A special starter is configured so that full voltage can be applied to one half of the winding, and then after a short delay, to the second half. This method can reducethe starting current by 50 to 60%, but also the starting torque. One drawback to this method is that the motor heating on the first step of the operation is greater than that normally encountered on across-the-line start. Therefore the elapsed time on the first step of the part winding start should be minimized. This method also increases the magnetic noise of the motor during the first step.IV .ConclusionThere are many ways asynchronous motor starting, according to the constraints of power systems, equipment costs, load the boot device to select the best method. From the device point of view, was the first full-pressure launch the cheapest way, but it may increase the cost efficiency in the use of, or the power supply system in the region can not meet their needs. Effective way to alleviate the buck starts the power supply system, but at the expense of the cost of starting torque.These methods may also lead to increased motor sizes have led to produce the required load torque. Inverter can be eliminated by the above two shortcomings, but requires an additional increase in equipment costs. Understand the limitations of the application, and drives the starting torque and speed, allowing you for your application to determine the best overall configuration.中文译文异步电动机起动的方法作者：J Larabee ， B Pellegrino ， B Flick摘要:大容量的交流异步电动机有多种启动方法。
电动机无级调速毕业设计--外文翻译资料
Ⅰ.system analysis and synthesis1．Analysis（1）In the speed and current dual closed-loop speed control system, in order to change the motor speed, what parameters should be regulating? Change speed regulator Kn magnification work? Power electronic converter to change the magnification factor Ks work? Change the speed of the feedback coefficient of work? To change the motor's stall current system should adjust the parameters of what?A: To change the motor speed, change speed regulator Kn magnification and power electronic converters will not work magnification factor Ks, stable when n = Un = Un *, so the only change in the value of a given coefficient of Un * and feedback before. To change the motor's stall current, only need to change the same value given Uim * and feedback coefficient, because the stability, Uim * = Idm, can be drawn from the type(2) Speed, the current double closed-loop speed control system when the steady-state operation, the two regulator input voltage and output voltage deviation is the number?A: The speed and current dual closed-loop speed control system when the steady-state operation, the two regulators are the input bias voltage is zero, by the formula n = Un = Un *, n = n; Uim * = Idm, Idm = Idl.(3) In the speed and current dual closed-loop speed control system, the two regulators are PI regulator. When the system is running with rated load, the speed feedback line suddenly disconnected, the system re-enter the steady-state, the current regulator is the input bias voltage to zero? Why?A: When the system is running with rated load, the speed feedback line suddenly disconnected, then Un = 0, = Un *- Un = Un *, so that Ui to reach Uim, 0, rate of increase in n, when the system after re-entering the steady-state , that is, Id = Idl, then, = Uim *- Idl 0, are no longer changes, changes in rotational speed n is no longer, but at this time than the rotational speed n at the time of the feedback line speed to break big.(4) Why is the speed with integral control system is not static poor?A: Speed regulator integral system, to achieve non-static error is due to the characteristics of integral control regulator, that is, the accumulation of points and the role of memory.(5) Double-loop speed control system (PI), load changes, Idl> Idm, asked bicyclol speed control system ASR and ACR how-conditioning, the result?A: When the load changes, Idl> Idm, speed decreased rapidly, the current Id soon to Idm, and of limited amplitude, rapid rate of ASR saturation, ACR has been limiting conditions, to form a blocking phenomenon, long-running will damage the system.2. SystemSpeed regulator and current regulator in the Double Loop DC Motor Control System can be summarized as follows:(1). The role of speed regulatorSpeed regulator is a speed control system of the dominant regulator, which allows speed n will soon change with a given voltage Un * changes in steady-state speed error can be reduced, if the PI regulator can achieve the non-static error.1) The effect of load changes in the role of anti-disturbance.2) The output amplitude of the decision limit the maximum allowable motor current.(2) The role of current regulator1) As a regulator of the inner ring, outer ring at the speed of the adjustment process, it makes the current closely followed the given voltage Ui * (that is, the outer ring modulator output) changes.2) Fluctuations in voltage from the role of disturbance rejection in time.3) The speed of the dynamic process of ensuring that the maximum allowable motor current, thereby speeding up the dynamic process.4) When the motor overload or stall when the armature current limit of the maximum, automatic protection from the role of acceleration. Once the faultdisappears, the system automatically return to normal. Yesterday, the role of the reliable operation is very important.Ⅱdouble-loop speed control system common faults analysis1.Introduction of a system(1). Double-loop speed control system components in Figure 1. Current loop: from the current regulator LT, trigger CF (input transformation for the CSR), silicon-controlled rectifier bridge, motor armature and current loop transform LB component. the speed of outer ring: the speed regulator from ST, current loop, such as link inertia, motor and load moment of inertia and the speed of transformation components SB. in the double-loop speed control system, the speed of the decision loop of the running characteristics of the whole system and stability, and play a leading role, and to change the current ring plays the role of the internal structure of the system is dependent, but since it is as a whole to participate in the closed-loop speed to the speed of a direct impact on the work of the closed-loop, it must first good debugging current loop, and then testing the speed of outer ring, so that the whole system has good dynamic performance.(2). Double-loop speed control system of the typical working condition1) Start (or the speed):ST in the start-up process has been saturated, so that the speed of this loop in the equivalent open-loop state. System only in the constant current loop under the regulation to ensure the motor at a constant current of the maximum allowable under the start-up.Figure 1 double-loop speed control system structure2) slow down (or stop):ST at this time to reach the output amplitude of the reverse limit. Main circuit current by the bridge is reduced to zero after the inverter. LT and CSR output will soon reach the maximum reverse. CF pulse output to reach βmin, current loop for open-loop. motor torque under deceleration until the motor speed close to the given new value, current loop and speed loop one after another into the closed-loop work, motor in the new value of a given run .3) Grid voltage fluctuation: This motor because of the larger moment of inertia, which caused the first change in armature current, ST output also did not change the effect of current loop, LT rapidly changing the output so that angle α be adjusted quickly, so the impact on the speed .4）Small changes in load: in the operation, load changes, will cause the motor speed deviation from the given value. speed up the recovery process and the aforementioned speed (or deceleration) is similar to the process.2. Common Fault Analysis and Processing(1) The normal supply voltage, thyristor rectifier output waveform arrhythmia caused by this phenomenon is due to trigger sawtooth slope caused inconsistency. Sawtooth slope adjust potentiometer, the output waveform uniformity could be achieved. in the adjustment process to strike a balance between Qi, this point should be paid attention to the actual debugging.(2) DC Motor Analysis of mechanical properties of soft thyristor DC motor system, when the current intermittent mechanical properties when the first no-load speed is characterized by high ideals, and the second is characterized by mechanical properties of soft . The so-called mechanical features soft, that is, small changes in load will cause great changes in speed. oscilloscope to observe when using the bridge rectifier output waveform, one may find that missing relative. at this time need to check whether the trigger has pulse output, fast whether the fuse melting, whether the breakdown or thyristor circuit,synchronous transformer is damaged, whether the lack of power. to identify the problems, can be resolved.(3) The speed of the speed of instability caused by many factors of instability:1) Electric guns are not firmly fixed or with the host of different axis .2) The parameters of the speed regulator inappropriate. Respond to the dynamic parameters to adjust (change the ratio of integral parameters ) .3) Of a speed control system there are(or bad)4) May be caused as a result of interference. should be found to interfere with the reasons for taking anti-jamming measures.(4) A little to the set rated motor speed is higher than that should first check whether it is normal for the external control system, such as outside the normal control system, it may be given points, speed regulator, current regulator, such as caused by link failure. Should be cut off the main circuit power supply, only the control system to the electricity, not a given in the case, testing each of the key points (such as the current regulator, voltage regulator, etc. of the potential. and then given together with the former to one by one after each of the key points to check the potential changes, you can find out the fault lies.(5) Bridge rectifier output voltage is not high stressed 1) the speed regulator and current regulator limiter too small, should be liberalized in accordance with appropriate amplitude threshold .2) than the speed feedback signal, in that they can reduce the rate of appropriate feedback signals.(6) To the timing system still in the absence of low-speed operation (that is, the phenomenon of emergence of reptiles) This is because the system of "zero drift" caused by. When the input signal is zero, the output voltage by the input amplification stage of the offset potentiometer decisions can be offset by adjusting the potential allows α = 90 °, at this time to zero output voltage rectification system, the electrical will not crawl.(7) With a given system can not runShould first check whether it is normal for the external control system, such as outside the normal control system, it may be given points, speed regulator, currentregulator, such as caused by link failure. Shall be cut off main circuit power supply, only the control system to the electricity, not Add the given circumstances, the key points of each test (such as the current regulator, voltage regulator, etc.) of the potential. and then combined with a given, after the previous one by one to each of the key points to check the potential changes, that is, where to find fault. (8) Lack of control accuracy in the distributor for a given run-time external control often requires precision sufficient parking in order to work properly. If poor precision parking, you can adjust the speed of the appropriate regulator of the PI link, generally by reducing the the ratio of the integral part of efforts to get satisfactory results.(9) Reversible system oscillation 1) open-loop system in the state (the main circuit disconnect) the oscillation can be changed at this time given the previous inspection to the key points of the potential changes. If a given unchanged, but the potential is still a point of change, here is the crux of .2) system in the state when the closed-loop oscillation, in which case in order to ensure the safety of the electrical load should be replaced by the general resistance of the load, if there is no suitable resistance box which can be used in place of the two electric sub-series. inspection methods and similar open-loop, focusing on the link to check is: given points, level detection, operation control, such as the speed regulator. oscillations are often caused as a result of operational amplifiers, such as damage to electronic components , system parameters caused by improper, according to the specific circumstances, properly addressed.一、系统分析与综合1.系统分析（1）在转速、电流双闭环调速系统中，若要改变电动机的转速，应调节什么参数？改变转速调节器的放大倍数Kn行不行？改变电力电子变换器的放大系数Ks行不行？改变转速反馈系数∂行不行？若要改变电动机的堵转电流，应调节系统中的什么参数？答：若要改变电动机的转速，改变转速调节器的放大倍数Kn和电力电子变换器的放大系数Ks都不行，稳定时∂n=Un=Un*,所以只有改变给定值Un*和反馈系数∂才行。
毕业设计(论文)外文资料翻译(学生用)
毕业设计外文资料翻译学院：信息科学与工程学院专业：软件工程姓名： XXXXX学号： XXXXXXXXX外文出处： Think In Java (用外文写)附件： 1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文网络编程历史上的网络编程都倾向于困难、复杂，而且极易出错。
程序员必须掌握与网络有关的大量细节，有时甚至要对硬件有深刻的认识。
一般地，我们需要理解连网协议中不同的“层”（Layer）。
而且对于每个连网库，一般都包含了数量众多的函数，分别涉及信息块的连接、打包和拆包；这些块的来回运输；以及握手等等。
这是一项令人痛苦的工作。
但是，连网本身的概念并不是很难。
我们想获得位于其他地方某台机器上的信息，并把它们移到这儿；或者相反。
这与读写文件非常相似，只是文件存在于远程机器上，而且远程机器有权决定如何处理我们请求或者发送的数据。
Java最出色的一个地方就是它的“无痛苦连网”概念。
有关连网的基层细节已被尽可能地提取出去，并隐藏在JVM以及Java的本机安装系统里进行控制。
我们使用的编程模型是一个文件的模型；事实上，网络连接（一个“套接字”）已被封装到系统对象里，所以可象对其他数据流那样采用同样的方法调用。
除此以外，在我们处理另一个连网问题——同时控制多个网络连接——的时候，Java内建的多线程机制也是十分方便的。
本章将用一系列易懂的例子解释Java的连网支持。
15.1 机器的标识当然，为了分辨来自别处的一台机器，以及为了保证自己连接的是希望的那台机器，必须有一种机制能独一无二地标识出网络内的每台机器。
早期网络只解决了如何在本地网络环境中为机器提供唯一的名字。
但Java面向的是整个因特网，这要求用一种机制对来自世界各地的机器进行标识。
为达到这个目的，我们采用了IP（互联网地址）的概念。
IP以两种形式存在着：(1) 大家最熟悉的DNS（域名服务）形式。
我自己的域名是。
所以假定我在自己的域内有一台名为Opus的计算机，它的域名就可以是。
【精品毕设】机电专业论文英文文献及其中文译文
毕业论文外文文献翻译译文题目:INTEGRATION OF MACHINERY外文资料翻译资料来源：文章名：INTEGRATION OF MACHINERY 《Digital Image Processing》书刊名：作者：Y. Torres J. J. Pavón I. Nieto and J. A.Rodríguez章节：2.4 INTEGRATION OF MACHINERYINTEGRATION OF MACHINERY （From ELECTRICAL AND MACHINERY INDUSTRY）ABSTRACT Machinery was the modern science and technology development inevitable resultthis article has summarized the integration of machinery technology basic outlineand the development background .Summarized the domestic and foreign integration ofmachinery technology present situation has analyzed the integration of machinerytechnology trend of development. Key word：integration of machinery ，technology，present situation ，productt，echnique of manufacture ，trend of development 0. Introduction modern science and technology unceasing development impelleddifferent discipline intersecting enormously with the seepage has caused the projectdomain technological revolution and the transformation .In mechanical engineeringdomain because the microelectronic technology and the computer technology rapiddevelopment and forms to the mechanical industry seepage the integration of machinerycaused the mechanical industry the technical structure the product organizationthe function and the constitution the production method and the management systemhas had the huge change caused the industrial production to enter into quottheintegration of machineryquot by quotthe machinery electrificationquot for the characteristicdevelopment phase. 1. Integration of machinery outline integration of machinery is refers in theorganization new owner function the power function in the information processingfunction and the control function introduces the electronic technology unifies thesystem the mechanism and the computerization design and the software whichconstitutes always to call. The integration of machinery development also has becomeone to have until now own system new discipline not only develops along with thescience and technology but also entrusts with the new content .But its basiccharacteristic may summarize is: The integration of machinery is embarks from thesystem viewpoint synthesis community technologies and so on utilization mechanicaltechnology microelectronic technology automatic control technology computertechnology information technology sensing observation and control technologyelectric power electronic technology connection technology information conversiontechnology as well as software programming technology according to the systemfunction goal and the optimized organization goal reasonable disposition and thelayout various functions unit in multi-purpose high grade redundant reliable inthe low energy consumption significance realize the specific function value andcauses the overall system optimization the systems engineering technology .From thisproduces functional system then becomes an integration of machinery systematic orthe integration of machinery product. Therefore quotintegration of machineryquot coveringquottechnologyquot and quotproductquot two aspects .Only is the integration of machinerytechnology is based on the above community technology organic fusion one kind ofcomprehensivetechnology but is not mechanical technical the microelectronictechnology as well as other new technical simple combination pieces together .Thisis the integration of machinery and the machinery adds the machinery electrificationwhich the electricity forms in the concept basic difference .The mechanicalengineering technology has the merely technical to develop the machineryelectrification still was the traditional machinery its main function still wasreplaces with the enlargement physical strength .But after develops the integrationof machinery micro electron installment besides may substitute for certainmechanical parts the original function but also can entrust with many new functionslike the automatic detection the automatic reduction information demonstrate therecord the automatic control and the control automatic diagnosis and the protectionautomatically and so on .Not only namely the integration of machinery product ishumans hand and body extending humans sense organ and the brains look has theintellectualized characteristic is the integration of machinery and the machineryelectrification distinguishes in the function essence. 2. Integration of machinery development condition integration of machinerydevelopment may divide into 3 stages roughly.20th century 60s before for the firststage this stage is called the initial stage .In this time the people determinationnot on own initiative uses the electronic technology the preliminary achievement toconsummate the mechanical product the performance .Specially in Second World Warperiod the war has stimulated the mechanical product and the electronic technologyunion these mechanical and electrical union military technology postwar transferscivilly to postwar economical restoration positive function .Developed and thedevelopment at that time generally speaking also is at the spontaneouscondition .Because at that time the electronic technology development not yetachieved certain level mechanical technical and electronic technology union alsonot impossible widespread and thorough development already developed the productwas also unable to promote massively. The 20th century 7080 ages for the second stagemay be called the vigorous development stage .This time the computer technologythe control technology the communication development has laid the technology basefor the integration of machinery development . Large-scale ultra large scaleintegrated circuit and microcomputer swift and violent development has provided thefull material base for the integration of machinery development .This timecharacteristic is :①A mechatronics word first generally is accepted in Japanprobably obtains the quite widespread acknowledgment to 1980s last stages in theworldwide scale ②The integration of machinery technology and the product obtainedthe enormous development ③The various countries start to the integration ofmachinery technology and the product give the very big attention and the support.1990s later periods started the integration of machinery technology the new stagewhich makes great strides forward to the intellectualized direction the integrationof machinery enters the thorough development time .At the same time optics thecommunication and so on entered the integration of machinery processes thetechnology also zhan to appear tiny in the integration of machinery the footappeared the light integration of machinery and the micro integration of machineryand so on the new branch On the other hand to the integration ofmachinery systemmodeling design the analysis and the integrated method the integration ofmachinery discipline system and the trend of development has all conducted thethorough research .At the same time because the hugeprogress which domains and so on artificial intelligence technology neural networktechnology and optical fiber technology obtain opened the development vast worldfor the integration of machinery technology .These research will urge theintegration of machinery further to establish the integrity the foundation and formsthe integrity gradually the scientific system. Our country is only then starts fromthe beginning of 1980s in this aspect to study with the application .The State Councilhad been established the integration of machinery leading group and lists as quot863plansquot this technology .When formulated quot95quot the plan and in 2010 developed thesummary had considered fully on international the influence which and possiblybrought from this about the integration of machinery technology developmenttrend .Many universities colleges and institutes the development facility and somelarge and middle scale enterprises have done the massive work to this technicaldevelopment and the application does not yield certain result but and so on theadvanced countries compared with Japan still has the suitable disparity. 3. Integration of machinery trend of development integrations of machinery arethe collection machinery the electron optics the control the computer theinformation and so on the multi-disciplinary overlapping syntheses its developmentand the progress rely on and promote the correlation technology development and theprogress .Therefore the integration of machinery main development direction is asfollows: 3.1 Intellectualized intellectualizations are 21st century integration ofmachinery technological development important development directions .Theartificial intelligence obtains day by day in the integration of machineryconstructors research takes the robot and the numerical control engine bedintellectualization is the important application .Here said quottheintellectualizationquot is to the machine behavior description is in the control theoryfoundation the absorption artificial intelligence the operations research thecomputer science the fuzzy mathematics the psychology the physiology and the chaosdynamics and so on the new thought the new method simulate the human intelligenceenable it to have abilities and so on judgment inference logical thinkingindependent decision-making obtains the higher control goal in order to .Indeedenable the integration of machinery product to have with the human identicalintelligence is not impossible also is nonessential .But the high performancethe high speed microprocessor enable the integration of machinery product to havepreliminary intelligent or humans partial intelligences then is completelypossible and essential. In the modern manufacture process the information has become the controlmanufacture industry the determining factor moreover is the most active actuationfactor .Enhances the manufacture system information-handling capacity to become themodern manufacture science development a key point .As a result of the manufacturesystem information organization and structure multi-level makes the information thegain the integration and the fusion presents draws up the character informationmeasuremulti-dimensional as well as information organizations multi-level .In themanufacture information structural model manufacture information uniform restraintdissemination processing and magnanimous data aspects and so on manufacture knowledgelibrary management all also wait for further break through. Each kind of artificial intelligence tool and the computation intelligence methodpromoted the manufacture intelligence development in the manufacture widespreadapplication .A kind based on the biological evolution algorithm computationintelligent agent in includes thescheduling problem in the combination optimization solution area of technologyreceives the more and more universal attention hopefully completes the combinationoptimization question when the manufacture the solution speed and the solutionprecision aspect breaks through the question scale in pairs the restriction .Themanufacture intelligence also displays in: The intelligent dispatch the intelligentdesign the intelligent processing the robot study the intelligent control theintelligent craft plan the intelligent diagnosis and so on are various These question key breakthrough may form the product innovation the basicresearch system. Between 2 modern mechanical engineering front science differentscience overlapping fusion will have the new science accumulation the economicaldevelopment and societys progress has had the new request and the expectation tothe science and technology thus will form the front science .The front science alsohas solved and between the solution scientific question border area .The front sciencehas the obvious time domain the domain and the dynamic characteristic .The projectfront science distinguished in the general basic science important characteristicis it has covered the key science and technology question which the project actualappeared. Manufacture system is a complex large-scale system for satisfies the manufacturesystem agility the fast response and fast reorganization ability must profit fromthe information science the life sciences and the social sciences and so on themulti-disciplinary research results the exploration manufacture system newarchitecture the manufacture pattern and the manufacture system effectiveoperational mechanism .Makes the system optimization the organizational structureand the good movement condition is makes the system modeling the simulation andthe optimized essential target .Not only the manufacture system new architecture tomakes the enterprise the agility and may reorganize ability to the demand responseability to have the vital significance moreover to made the enterprise first floorproduction equipment the flexibility and may dynamic reorganization ability set ahigher request .The biological manufacture view more and more many is introduced themanufacture system satisfies the manufacture system new request. The study organizes and circulates method and technique of complicated systemfrom the biological phenomenon is a valid exit which will solve many hard nut tocracks that manufacturing industry face from now on currently .Imitating to livingwhat manufacturing point is mimicry living creature organ of from the organizationfrom match more from growth with from evolution etc. function structure and circulatemode of a kind of manufacturing system and manufacturing process. The manufacturing drives in the mechanism under continuously by ones ownperfect raise on organizing structure and circulating modeand thus to adapt theprocess ofwith ability for the environment .For from descend but the last productproceed together a design and make a craft rules the auto of the distance born producesystem of dynamic state reorganization and product and manufacturing the system tendautomatically excellent provided theories foundation and carry out acondition .Imitate to living a manufacturing to belong to manufacturing science andlife science ofquotthe far good luck is miscellaneous to hand overquot it will produceto the manufacturing industry for 21 centuries huge of influence .机电一体化摘要机电一体化是现代科学技术发展的必然结果本文简述了机电一体化技术的基本概要和发展背景。
电子电气类专业毕业设计外文翻译
附录一：外文原文Super capacitors - An OverviewKey words: Electrostatic capacitor; Electrolytic capacitor; Ceramic capacitor;Electrical double layer capacitor; Super Capacitor1.INTRODUCTIONThis paper offers a concise review on the renaissance of a conventional capacitor toelectrochemical double layer capacitor or super capacitor. Capacitors are fundamental electrical circuitelements that store electrical energy in the order of microfarads and assist in filtering. Capacitors havetwo main applications; one of which is a function to charge or discharge electricity. This function isapplied to smoothing circuits of power supplies, backup circuits of microcomputers, and timer circuitsthat make use of the periods to charge or discharge electricity. The other is a function to block the flowof DC. This function is applied to filters that extract or eliminate particular frequencies. This isindispensable to circuits where excellent frequency characteristics are required. Electrolytic capacitorsare next generation capacitors which are commercialized in full scale. They are similar to batteries in cell construction but the anode and cathode materials remain the same. They are aluminum, tantalum and ceramic capacitors where they use solid/liquid electrolytes with a separator between two symmetrical electro des.An electrochemical capacitor (EC), often called a Super capacitor or Ultra capacitor, stores electrical charge in the electric double layer at a surface-electrolyte interface, primarily in high-surface-area carbon. Because of the high surface area and the thinness of the double layer, these devices can have very a high specific and volumetric capacitance. This enables them to combine a previously unattainable capacitance density with an essentially unlimited charge/discharge cycle life. The operational voltage per cell ,limited only by the breakdown potential of the electrolyte, is usually<1 or <3 volts per cell for aqueous or organic electrolytes respectively.The concept of storing electrical energy in the electric double layer that isformed at the interface between an electrolyte and a solid has been known since the late 1800s. The first electrical device using double-layer charge storage was reported in 1957 by H.I. Becker of General Electric (U.S. Patent 2,800,616).Unfortunately, Becker’s device was imp ractical in that, similarly to a flooded battery, both electrodes needed to be immersed in a container of electrolyte, and the device was never comercialised.Becker did, however, appreciate the large capacitance values subsequently achieved by Robert A. Rightmire, a chemist at the Standard Oil Company of Ohio (SOHIO), to whom can be attributed the invention of the device in the format now commonly used. His patent (U.S. 3,288,641), filed in 1962 and awarded in late November 1966, and a follow-on patent (U.S. Patent 3,536,963) by fellow SOHIO researcher Donald L. Boos in 1970, form the basis for the many hundreds of subsequent patents and journal articles covering all aspects of EC technology.This technology has grown into an industrywith sales worth severalhundred million dollars per year. It is an in dustry that is poised today for rapid growth in the near term with the expansion of power quality needs and emerging transportation applications.Following the commercial introduction of NEC’s Super Capacitor in 1978, under licence from SOHIO, EC have evolved through several generations of designs. Initially they were used as back-up power devices for v is for cells ranging in size from small millifarad size devices with exceptional pulse power performance up to devices rated at hundreds of thousands of farads, with systems in some applications operating at up to 1,500 volts. The technology is seeing increasingly broad use, replacing batteriesolatile clock chips and complementary metal-oxide-semiconductor (CMOS) computer memories. But many other applications have emerged over the past 30 years, including portable wireless communication, enhanced power quality for distributed power generation systems, industrial actuator power sources, and high-efficiency energy storage for electric vehicles(EVs) and hybrid electric vehicles (HEVs).Overall, the unique attributes of ECs often complement the weaknesses of other power sources like batteries and fuel cells.Early ECs were generally rated at a few volts and had capacitance values measured from fractions of farads up to several farads. The trend today in some cases and in others complementing their performance.The third generation evolution is the electric double layer capacitor, where the electrical charge stored at a metal/electrolyte interface is exploited to construct astorage device. The interface can store electrical charge in the order of 610Farad. The main component in the electrode construction is activated carbon. Though this concept was initialized and industrialized some 40 years ago, there was a stagnancy in research until recent times; the need for this revival of interest arises due to the increasing demands for electrical energy storage in certain current applications like digital electronic devices, implantable medical devices and stop/start operation in vehicle traction which need very short high power pulses that could be fulfilled by electric double layer capacitors. They are complementary to batteries as they deliver high power density and low energy density. They also have longer cycle life than batteries and possess higher energy density as compared to conventional capacitors. This has led to new concepts of the so-called hybrid charge storage devices in which electrochemical capacitor is interfaced with a fuel cell or a battery. These capacitors using carbon as the main electrode material for both anode and cathode with organic and aqueous electrolytes are commercialized and used in day to-day applications. Fig.1 presents the three types of capacitors depicting the basic differences in their design and construction.Figure 1.Schematic presentation of electrostatic capacitor, electrolytic capacitor and electrical double layer capacitor.EDLCs, however suffer from low energy density. To rectify these problems, recently researchers try to incorporate transition metal oxides along with carbon in the electrode materials. When the electrode materials consist of transition metal oxides, then the electrosorption or redox processes enhance the value of specific capacitance ca. 10 -100 times depending on the nature of oxides. In such a situation, the EDLC is called as super capacitor or pseudo capacitor . This is the fourth generation capacitor. Performance of a super capacitor combines simultaneously two kinds of energy storage, i.e. non-faradic charge as in EDLC capacitors and faradaic charge similar toprocesses proceeding in batteries. The market for EC devices used for memory protection in electronic circuitry is about $150-200 million annually. New potential applications for ECs include the portable electronic device market, the power quality market, due particularly to distributed generation and low-emission hybrid cars, buses and trucks. There are some published reviews on capacitors and super capacitors . In the present overview, the evolution of electrochemical double layer capacitors starting from simple electrostatic capacitors is summarized.2. EXPERIMENTAL PARTThe invention of Leiden jar in 1745 started the capacitor technology; since then, there has been tremendous progress in this field. In the beginning, capacitors are used primarily in electrical and electronic products, but today they are used in fields ranging from industrial application to automobiles, aircraft and space, medicine, computers, games and power supply circuits. Capacitors are made from two metallic electrodes (mainly Si) placed in mutual opposition with an insulating material (dielectric) between the electrodes for accumulating an electrical charge. The basic equation relating to the capacitors is:C = εS/d (1)where C(μF) is the electrostatic capacity, the dielectric constant of the dielectric, S (cm2) the surface area of the electrode and d (cm) the thickness of the dielectric. The charge accumulating principle can be described as follows: when a battery is connected to the capacitor, flow of current induces the flow of electrons so that electrons are attracted to the positive terminal of the battery and so they flow towards the power source. As a result, an electron deficiency develops at the positive side, which becomes positively charged and an electron surplus develops at the negative side, which becomes negatively charged. This electron flow continues until the potential difference between the two electrodes becomes equal to the battery voltage. Thus the capacitor gets charged. Once the battery is removed, the electrons flow from the negative side to the side with an electron deficiency; this process leads to discharging. The conventional capacitors yield capacitance in the range of 0.1 to 1 μF with a voltage range of 50 to 400 V. Various materials such as paper (ε, 1.2-2.6), paraffin (ε 1.9-2.4), polyethylene (2.2-2.4), polystyrene (ε, 2.5-2.7), ebonite (ε, 2-3.5), polyethylene tetraphtharate (ε,3.1-3.2), water (ε, 80) sulfur（ε, 2-4.2), steatite porcelain (ε, 6-7), Al porcelain (ε, 8-10), mica（ε, 5-7)and insulated mineral oil (ε, 2.2-2.4) are used as dielectrics in capacitors.The capacitance output of these silicon based capacitors is limited and has to cope with low surface-to volume ratios of these electrodes. To increase the capacitance, as per eq., one has to increase to ∂or S and decrease; however the ∂value is largely determined by the working voltage and cannot be tampered. When aiming at high capacitance densities, it is necessary to combine the mutual benefits achieved with a high permittivity insulator material and an increased effective surface area. With Si as the substrate material, electrochemical etching produces effective surface area. The surface area of this material gets enlarged by two orders of magnitude compared to unetched surface. Electrochemically formed macroporous Si has been used for the preparation of high aspect ratio capacitors with layered SiO2/Si3N4/SiO2 insulators. Research work on the modification of conventional capacitors to increase the specific capacitance is also in progress. Approximately 30 times higher capacitance densities are reported recently for Si/Al2O3/ZnO: Al capacitor where Si is electrochemically etched porous one. Another way identified to increase the surface area of the electrodes is to form anodically formed oxides (Al, Ta); however, ceramic capacitors are based on the high dielectric constant rather than the electrode area.3. ELECTROLYTIC CAPACITORSThe next generation capacitors are the electrolytic capacitors; they are of Ta, Al and ceramic electrolytic capacitors. Electrolytic capacitors use an electrolyte as conductor between the dielectrics and an electrode. A typical aluminum electrolytic capacitor includes an anode foil and a cathode foil processed by surface enlargement and or formation treatments. Usually, the dielectric film is fabricated by anodizing high purity Al foil for high voltage applications in boric acid solutions. The thickness of the dielectric film is related to the working voltage of the aluminum electrolytic capacitor. After cutting to a specific size according to the design specification, a laminate made up of an anode foil, a cathode foil which is opposed to the dielectric film of the anode foil and a separator interposed between the anode and cathode foils, is wound to provide an element. The wound element does not have any electricalcharacteristics of electrolytic capacitor yet until completely dipped in an electrolyte for driving and housed in a metallic sheathed package in cylindrical form with a closed-end equipping a releaser. Furthermore, a sealing material made of elastic rubber is inserted into an open-end section of the sheathed package and the open-end section of the sheathed package by drawing, whereby an aluminum electrolytic capacitor is constituted. Electrolytic aluminum capacitors are mainly used as power supplies for automobiles, aircraft, space vehicles, computers, monitors, motherboards of personal computers and other electronics.There are two types of tantalum capacitors commercially available in the market; wet electrolytic capacitors which use sulfuric acid as the electrolyte and solid electrolytic capacitors which use MnO2 as the solid electrolyte. Though the capacitances derived from both Ta and Al capacitors are the same, Ta capacitors are superior to Al capacitors in temperature and frequency characteristics. For analog signal systems, Al capacitors produce a current-spike noise which does not happen in Ta capacitors. In other words, Ta capacitors are preferred for circuits which need high stability characteristics. The total world wide production of Al electrolytic capacitors amounts to US$ 3.8 billion, 99% of which are of the wet type. Unlike Ta solid electrolytic capacitors, the solid electrolyte materials used are of organic origin; polypyrrole, a functional polymer and TCNQ (7,7, 8, 8- tetracyanoquniodimethane) an organic semiconductor. Next, MnO2 solid electrolyte material is formed on the surface of that dielectric layer and on top of that a layer of polypyrrole organic solid electrolyte material is formed by electrolytic synthesis. Following this, the positive and negative electrodes are mounted to complete the electronic component. However, the capacitances of these electrolytic capacitors are in the range 0.1 to 10F with a voltage profile of 25 to 50 V.The history of development of electrolytic capacitors which were mass produced in the past as well as today is presented by S. Niwa and Y. Taketani . Many researchers try to improve the performance of these electrolytic capacitors by modifying the electrode or electrolyte. Generally, the increases in effective surface area (S) are achieved by electrolytic etching of aluminum substrate before anodization, but now it faces with the limit. It is also very difficult to decrease d because the d value is largely decided when the working voltages are decided. Increase in may be a possible routine to form composite dielectric layers by incorporating relatively large value compounds. Replacement of MnO2 by polypyrrole solid electrolyte was reported to reduce electrostatic resistance due to its higher conductivity; aromaticsulfonate ions were used as charge compensating dopant ions .A tantalum capacitor with Ta metal as anode, polypyrrole as cathode and Ta2O5 dielectric layer was also reported. In the Al solid electrolytic capacitors, polyaniline doped with inorganic and organic acids was also studied as counter electrode. In yet another work, Al solid electrolytic capacitor with etched Al foil as anode, polyaniline / polypyrrrole as cathode and Al2O3 as dielectric was developed. Ethylene carbonate based organic electrolytes and -butyrolactone based electrolytes have been tried as operating electrolytes in Al electrolytic capacitors. Masuda et al. have obtained high capacitance by electrochemically anodizing rapidly quenching Al-Ti alloy foil. Many researchers have tried the other combination of alloys such as Al-Zr, Al-Si, Al-Ti, Al-Nb and Al-Ta composite oxide films. Composite oxide films of Al2O3-(Ba0.5Sr0.5TiO3) and Al2O3- Bi4Ti3O12 on low-voltage etched aluminum foil were also studied. Nb-Ta-Al for Ta electrolytic capacitors was also tried as anode material .A ceramic capacitor is a capacitor constructed of alternating layers of metal and ceramic, with the ceramic material acting as the dielectric. Multilayer ceramic capacitors (MLCs) typically consist of ~100 alternate layers of electrode and dielectric ceramics sandwiched between two ceramic cover layers. They are fabricated by screen-printing of electrode layers on dielectric layers and co-sintering of the laminate. Conventionally, Ag-Pd is used as the electrode material and BaTiO3 is used as the dielectric ceramic. From 2000 onwards, the MLCs market has been growing in pace with the exponential development of communications. They are produced in the capacitance range of 10 F (normally the range of Ta and Al electrolytic capacitors); they are highly useful in high frequency applications. Historically, a ceramic capacitor is a two-terminal non-polar device. The classical ceramic capacitor is the disc capacitor. This device predates the transistor and was used extensively in vacuum-tube equipment (e.g radio receivers) from c. a. 1930 through the 1950s and in discrete transistor equipment from the 1950s through the 1980s. As of 2007, ceramic disc capacitors are in widespread use in electronic equipment, providing high capacity and small size at low price compared to the other types.The other ceramic materials that have been identified and used are CaZrO3, MgTiO3, SrTiO3 etc. A typical 10 F MLC is a chip of size (3.2 x 1.6 x 1.5 mm). Mn, Ca, Pd , Ag etc are some of the other internal electrodes used. Linear dielectrics and antiferroelectrics based o strontium titante have been developed for high voltage disk capacitors. These are applicable for MLCs with thinner layers because of their high coercive fields. One of the most critical material processing parameters is the degreeof homogeneous mixing of additive in the slurry. The binder distribution in the green ceramic sheet, the degree of surface roughness, fine size nickel powder, formation of green sheet, electrode deposition ad sheet stacking etc play a crucial role in the process technology. Any one of these facts if mishandled would result in the failure of the device. For instance, providing a roughess of 5 m thick green sheet to 0.5 m is mandatory so that a smooth contact surface with the inner nickel electrode can be established. This is a very important factor in avoiding the concentration of electric filed at asperities, where the charge emission from the electrode is accelerated, resulting in short failure. Conventional sheet/printing method has a technical limit of producing a thickness around 1 m dielectric; in order to decrease the thickness further, thin film technologies like CVD, sputtering, plasma-spray etc has to be used.The other types of capacitors are film capacitors which use thin polyester film and polypropylene film as dielectrics and meta-glazed capacitors which incorporate electrode plates made of film vacuum evaporated with metal such as Al. Films can be of polyester, polypropylene or polycarbonate make. Also capacitors are specified depending on the dielectric used such as polyester film capacitor, polypropylene capacitor, mica capacitor, metallized polyester film capacitor etc.4. DOUBLE LAYER CAPACITORSElectric/electrochemical double layer capacitor (EDLC) is a unique electrical storage device, which can store much more energy than conventional capacitors and offer much higher power densitythan batteries. EDLCs fill up the gap between the batteries and the conventional capacitor, allowing applications for various power and energy requirements i.e., back up power sources for electronic devices, load-leveling, engine start or acceleration for hybrid vehicles and electricity storage generated from solar or wind energy. EDLC works on the principle of double-layer capacitance at the electrode/electrolyte interface where electric charges are accumulated on the electrode surfaces and ions of opposite charge are arranged on the electrolyte side.Figure 2.Charge storage mechanism of an EDLC cell under idle and charged conditions.Fig. 2 shows the mechanism of charge storage in an EDLC cell and Fig. 3 shows the configuration of an typical EDLC cell. There are two main types of double layer capacitors as classified by the charge storage mechanism: (i) electrical double-layer capacitor; (ii) electrochemical double layer capacitor or super/pseudocapacitor. An EDLC stores energy in the double-layer at the electrode/electrolyte interface, whereas the supercapacitor sustains a Faradic reaction between the electrode and the electrolyte in a suitable potential window. Thus the electrode material used for the construction of the cell for the former is mainly carbon material while for the latter, the electrode material consist of either transition metal oxides or mixtures of carbon and metal oxides/polymers. The electrolytes can be either aqueous or non-aqueous depending on the mode of construction of EDLC cell.Figure 3.Typical configuration of an EDLC cellThere are two general directions of interest. One is the long term goal of the development of electrical propulsion for vehicles, and the other is the rapid growth of portable electronic devices that require power sources with maximum energy content and the lowest possible size and weight.5. CONCLUSIONSAccording to a market survey by Montana, super capacitors are becoming a promising solution for brake energy storage in rail vehicles. The expected technological development outside railway sector is also shown to be highly dynamic: diesel electric vehicles, catenary free operation of city light rail, starting system for diesel engines, hybrid-electric cars, industrial applications, elevators, pallet trucks etc. The time horizon expected for development is next 5 to 10 years. The main development goals will be,· long life time· increase of the rated voltage· improvements of the range of operating temperature· increase of the energy and power densitiesVery recently, hybrid car is introduced in the market but it is turned to be very expensive and out of common man’s reach. Shortage and cost of fossil fuels already instigated alternate technologies viable for traction purposes. In such a situation,EDLCs are also useful to store energy generated from non-conventional energy sources. A future possibility of service centers set up for EDLC supply similar to petrol (as on date) is not far as the main setbacks in technology development may take a decade for fruitful results.附录二：外文译文超级电容器-概述关键词：静电电容，电解电容器，陶瓷电容器，双电层 ,电容器，超级电容器1．引言本文为电化学双层电容器或超级电容器提供在一台常规电容器，简明的介绍新生的电化学双电层电容器或超级电容器。
电机学英文文献翻译
The three-phase induction motor speed control methodThree-phase asynchronous motor speed formula: N = 60f / p (1-s) Can be seen from the above formula, change the power supply frequency f, motor pole number p and the slip s may be too much to change the speed of purpose. From the speed of the essence of view, is simply a different way to change speed synchronous AC motor does not change the sync transfer speed or two.Widespread use in production machines without changing the synchronous speed of motor speed control method Wound Rotor Series Resistance Speed, chopper speed control, cascade control, and application of electromagnetic slip clutch, fluid couplings, clutches and other film speed. Change the synchronous speed of change on the number of stator pole multi-speed motor to change the stator voltage and frequency to frequency conversion with no change to the motor speed and so on.Energy from the speed point of view when, with high speed method and inefficient methods of two kinds of speed: high speed when the slip refers to the same, so no slip losses, such as multi-speed motors, Slip frequency control and loss can speed recovery methods (such as cascade control, etc.). A deteriorating loss of speed control methods are inefficient speed, such as series resistance of the rotor speed method, the energy loss in the rotor circuit on; Electromagnetic Clutch The speed method, the energy loss in the clutch coils; fluid coupling speed, energy loss in the fluid coupling of the oil. General deterioration in loss increased with the expansion speed range, if not speed range, the energy loss is minimal.1, variable speed control method of pole pairsThis speed is then used to change the stator winding way to change the red cage motor stator pole pairs to achieve speed control purposes, the followingfeaturesWith hard mechanical properties, good stability;No slip loss, high efficiency; Wiring simple, easy to control, low price;A level speed, differential large, can not get smooth speed control;With pressure and speed adjustment, with the use of electromagnetic slip clutch,smooth and efficient access to high speed characteristics.This method is suitable for the production does not require variable speed machinery, such as metal cutting machine Bed , Lift , Lifting equipment, Fans Water Pump And so on.2, Frequency Control Method Frequency control is to change the motor stator Power supply Frequency, thus changing the speed of its synchronous speed method. Frequency control system main equipment is to provide variable frequency power supply Inverter , Inverter can be divided into AC - DC - AC inverter and AC - AC converter two categories, most of the current domestic use of AC - DC - AC inverter. Its characteristicsHighefficiency, speed the process without additional loss;Wide range of applications, can be used for cage induction motor;Speed range, features a hard, high accuracy;Technical complexity, high cost, difficult maintenance and overhaul.This method is suitable for the high accuracy, good speed performance occasions.3, cascade control method Cascade control is wound into the rotor circuit in the series of additional potential can be adjusted to change the motor's slip, to achieve speed control purposes. Most of the deterioration in power to be in series with the added potential absorbed, re-use generate additional devices to absorb the deterioration in power to return power to use or conversion of energy. Slip-power absorption under way, cascade control can be divided into Motor Cascade control, mechanical and thyristor cascade control cascade control, and multi-use cascade control thyristor, characterized byCan speed the process of deterioration in loss of feedback to the network or productionmachinery, more efficient;Installed capacity and speed range in direct proportion to investment, applicable speed range 70% -90% rated speed of production machinery;peed device failure can switch to full speed, to avoid the cut-off;Thyristor cascade speed low power factor, harmonics greater impact.This method is suitable for fans, pumps and rolling mills, mine hoist, extrusion machines.4, wound rotor motor speed control method of Series ResistanceWound Rotor Motor additional resistance in series, so that the motor slip up, motor running at low speed. The greater the resistance in series, the motor speed is lower. This method is simple, easy to control, but deteriorate the power consumption in the form of heat in the resistor. Is a class speed, soft mechanical properties.5, the stator pressure and speed adjustment methodStator voltage when changing the motor, you can get a different set of mechanical properties of curves, which were different speeds. Since the motor torque and voltage proportional to the square, the largest decline in a lot of torque, speed range of its small cage motors in general and difficult to apply. In order to expand the speed range, pressure and speed adjustment should be larger rotor resistance value cage motors, such as dedicated voltage regulator with speed torque motor, or series wound motor frequency sensitive resistors. In order to expand the range of stable operation, when the speed of 2:1 or more occasions in the feedback control should be adopted to achieve the purpose of automatic adjustment of speed.Pressure and speed adjustment is a key device to provide power supply voltage, the current way of a tandem common saturation voltage regulator Reactor , Auto Transformer And several other Thyristor Surge. Thyristor Surge is the best way. Adjusting Speed featuresPressure and speed adjustment circuit is simple, easy to realize automatic control;Poor power surge process to heat transfer in the rotor resistance in the form of consumption, low efficiency.Pressure and speed adjustment generally applies to 100KW below production machinery.6.electromagnetic speed regulating motor speed control method of electromagneticspeed regulating electric motor squirrel cage motor, electric slip clutch and DC excitation power supply (Controller) consists of three parts. DC excitation power small, usually consisting of single phase half-wave or full wave rectifiers thyristors composition, change thyristor conduction angle, you can change the magnetizing current size.Electromagnetic slip clutch armature, poles and excitation windings composed of three parts. Armature and the latter has no mechanical contact, are free to rotate. Armature motor coaxial connection active part, driven by motors; docking with the load axis magnetic pole coupling from the moving parts. When the armature poles are at rest, such as excitation windings for DC, along the circumferential surface will form a number of air gap on the n, s, of alternating polarity poles, the magnetic flux through the armature. Dang electric armature with drag motor rotating Shi, due to electric armature and pole between relative movement, and makes electric armature induction produced Eddy, this Eddy and magnetic pass mutual role produced go moments, led has pole of rotor by same direction rotating, but its speed constant below electric armature of speed N1, this is a go difference adjustable speed way, changes go difference clutch device of DC Lai magnetic current, will can change clutch device of output go moments and speed. Characteristics of electromagnetic speed regulating motor speed:appliances, structure and control circuit is simple, reliable operation, easymaintenance; speed and smooth, stepless speed regulationthe power network harmonic effects;lost speed, low efficiency.This method applies to medium and small power, requires low speed when the smooth, short run production machinery.7. the hydraulic coupler speed regulating hydraulic Coupler is a device for hydraulic drive, is made up of the pump and turbine, they collectively work wheels, placed in a sealed case. Shell filled with a certain amount of working fluid, when pump is impulse driven by rotation, in which liquid propelled by blades which rotate, and under the action of centrifugal force along the outer wheels when entering the turbine pump, to thrust to the turbine blades on the same turn, make it drive production machinery running. Power transfer capacity of the hydraulic coupler and shell filled with fluid volume sizes are consistent. In the course of work, changing the filling rate can change the coupler of turbine speed, stepless speed regulation, characterized by:power scope, can meet the needs of from a couple of different power 10-kilowattto shuqianqian;simple structure, reliable performance, easy to operation and maintenance, andlow cost;small size, capacity;easy to adjust, easy to fulfill automatic control.This method applies to the speed of the fan and water pump.三相异步电动机的几种调速方式三相异步电动机转速公式为：n=60f/p(1-s)从上式可见，改变供电频率f、电动机的极对数p及转差率s均可太到改变转速的目的。
三相异步电动机故障诊断中英文翻译、外文翻译、外文文献翻译
翻译部分英文原文Fault Diagnosis of Three Phase Induction Motor Using Neural NetworkTechniquesAbstract：Fault diagnosis of induction motor is gaining importance in industry because of the need to increase reliability and to decrease possible loss of production due to machine breakdown.Due to environmental stress and many others reasons different faults occur in induction motor. Many researchers proposed different techniques for fault detection and diagnosis.However,many techniques available presently require a good deal of expertise to apply them successfully.Simpler approaches are needed which allow relatively unskilled operators to make reliable decisions without a diagnosis specialist to examine data and diagnose problems.In this paper simple,reliable and economical Neural Network(NN)based fault classifier is proposed,in which stator current is used as input signal from motor.Thirteen statistical parameters are extracted from the stator current and PCA is used to select proper input.Data is generated from the experimentation on specially designed 2 Hp,4 pole 50 Hz.three phase induction motor.For classification,NNs like MLP,SVM and statistical classifiers based on CART and Discriminant Analysis are verified.Robustness of classifier to noise is also verified on unseen data by introducing controlled Gaussian and Uniform noise in input and output.Index Terms: Induction motor, Fault diagnosis, MLP, SVM,CART, Discriminant Analysis, PCAI.INTRODUCTIONINDUCTION motors play an important role as prime movers in manufacturing,process industry and transportation due to their reliability and simplicity in construction.In spite of their robustness and reliability,they do occasionally fail,and unpredicted downtime is obviously costly hence they required constant attention.The faults of induction motors may not only cause the interruption of product operation but also increase costs,decrease product quality and affect the safety of operators.If the lifetime of induction machines was extended, and efficiency of manufacturing lines was improved,it would lead to smaller production expenses and lower prices for the end user.In order to keep machines in good condition, some techniques i.e.,fault monitoring, fault detection, and fault diagnosis have become increasingly essential.The most common faults of induction motors are bearing failures, stator phase winding failures ,broken rotor bar or cracked rotor end-rings and air-gap irregularities.The objective of this research is to develop an alternative neural network based incipient fault-detection scheme that overcome the limitations of the present schemes in the sense that,they are costly, applicable for large motors, furthermore many design parameters are requested and especially concerning to long time operating machines, these parameters cannot be available easily.As compared to existing schemes, proposed scheme is simple, accurate, reliable and economical. This research work is based on real time data and so proposed neural network based classifier demonstrates the actual feasibility in a real industrial situation. Four differentneural network structures are presented in this paper with all kinds of performances and about 100%classification accuracy is achieved.II.FAULT CLASSIFICATION USING NNThe proposed fault detection and diagnosis scheme consists of four procedures as shown in Fig.1:1. Data collection & acquisition2. Feature extraction3. Feature selection4. Fault classificationA. Data Collection and Data acquisitionIn this paper the most common faults namely stator winding interturn short(I),rotor dynamic eccentricity(E)and both of them(B)are considered.Fig.1.General Block Diagram of proposed classifierFor experimentation and data generation the specially designed 2 HP, three phase,4 pole,415V,50 Hz induction motor is selected. Experimental set up is as shown in Fig.2.Fig.2.Experimental SetupThe load of the motor was changed by adjusting the spring balance and belt.Three AC current probes were used to measure the stator current signals for testing the fault diagnosis system. The maximum frequency of used signal was 5 kHz and the number of sampled data was 2500.From the time waveforms of stator currents as shown in Fig.3,no conspicuous difference exists among the different conditions.Fig.3.Experimental Waveforms of Stator currentB. Feature ExtractionThere is a need to come up with a feature extraction method to classify faults.In order to classify the different faults,the statistical parameters are used.To be precise, ‘sample’ statistics will be calculated for current data.Overall thirteen parameters are calculated as input feature space.Minimum set of statistics to be examined includes the root mean square (RMS)of the zero mean signal(which is the standard deviation),the maximum, and minimum values the skew ness c oefficient and kurtosis coefficient. Pearson’s coefficient of skew ness,2g defined by:xS x x g ~32-= (1) Where x denotes mean,x denotes median and x S denotes the sample standard deviation.The sample coefficient of variation r v is defined by;xS v x r = (2) The th r sample moment about the sample mean for a data set is given by;nx x m r n i i r ∑=-=1)( (3) m 2 denotes spread about the center,m3 refers to skewness about the center;m4 denotes how much data is massed at the center. Second,third and fourth moments are used to define the sample coefficient of skewness,3g and the sample coefficient of kurtosis,4g as follows.()3233m m g = (4) ()4244m m g = (5)The sample covariance between dimensions j and k is defined as;)1())((1---=∑=n x x x x c n i k ik j ij jk (6)The ordinary correlation coefficient for dimensions j and k ,jk r is defined as;k j jkjk S S c r -= (7)C. Feature SelectionBefore a feature set is fed into a classifier,most superior features providing dominant fault-related information should be selected from the feature set,and irrelevant or redundant features must be discarded to improve the classifier performance and avoid the curse of dimensionality.Here Principal Component Analysis(PCA)technique is used to select the most superior features from the original feature set.Principal Components(PCs)are computed by Pearson rule.The Fig.4 is related to a mathematical object,the eigenvalues,which reflect thequality of the projection from the 13-dimensional to a lower number of dimensions.Fig.4.Principal Component, Eigenvalues and percent variabilityD. Fault Classifier(1)MLP NN Based ClassifierSimple Multilayer Perceptron(MLP)Neural Network is proposed as a fault classifier.Four Processing Elements are used in output layer for four conditions of motor namely Healthy, Inter turn fault,Eccentricity and Both faults. From results as shown in Fig.5,five PCAs are selected asinputs;hence number of PEs in input layer is five.Fig.5(a).Variation of Average MSE on training and CV with number of PCs as inputFig.5(b).Variation of Average Classification Accuracy on Testing on Testdata, Training data and CV data with number of PCs as input The randomized data is fed to the neural network and is retrained five times with different random weight initialization so as to remove biasing and to ensure true learning and generalization for different hidden layers.This also removes any affinity or dependence of choice of initial connection weights on the performance of NN.It is observed that MLP with a single hidden layer gives better performance.The number of Processing Elements(PEs)in the hidden layer is varied.The network is trained and minimum MSE is obtained when 5 PEs are used in hidden layer as indicated in Fig.6.Fig.6.Variation of Average MSE with number of PEs in Hidden Layer VariousTransferfunctions,namely,Tanh,Sigmoid,Liner-tanh,Linear-sigmoid,Softmax,Bias axon, Linear axon and learning rules, namely, Momentum, Conjugate-Gradient, Quick Propagation, Delta Bar Delta, and Step are verified for training, cross validation and testing.Minimum MSE and average classification accuracy on training and CV data set are compared . With above experimentations finally,the MLP NN classifier is designed with following specifications,Number of Inputs:5;Number of Hidden Layers:01;Number of PEs in Hidden Layer:04;Hidden Layer:Transfer function:tanh Learning Rule:MomentumStep size:0.6 Momentum:0.5Output Layer:Transfer function:tanh Learning Rule:MomentumStep size:0.1 Momentum:0.5Number of connection weights:44Training time required per epoch per exemplar:0.0063 ms(2) SVM NN Based ClassifierThe support vector machine(SVM)is a new kind of classifier that is motivated by two concepts. First , transforming data into a high-dimensional space can transform complex problems (with complex decision surfaces)into simpler problems that can use linear discriminant functions. Second, SVMs are motivated by the concept of training and using only those inputs that are near the decision surface since they provide the most information about the classification. It can be extended to multi-class.SVMs training always seek a global optimized solution and avoid over fitting,so it has ability to deal with a large number of feature.Generalized Algorithm for the classifier:x(i=1…N) this algorithm can be easily extended to For N dimensional space datainetwork by substituting the inner product of patterns in the input space by the kernel function, leading to the following quadratic optimization problem:∑∑∑===--=N i Nj j i j i j i N i i x x G d d J 1121)2,(21)(σαααα (8) Subject to01=∑=N i i id α {}N i i ,...1,0∈∀≥α (9)where ()2,σx G represents a Gaussian function, N is the number of samples,i αare a set of multipliers(one for each sample),∑=+-=N i j i j j i i b x x G d d x J 12))2,(()(σα (10)and)(m i n i ix g M = (11) and choose a common starting multiplier i α,learning rate η, and a small threshold. Then, while M>t, we choose a pattern i x and calculate an update ))(1(i i x g -=∆ηαand perform the update If 0)(>∆+i i n αα)()()1(n n n i i i ααα∆+=+i i d n b n b α∆+=+)()1( (12)And if 0)(≤∆+i i n αα)()1(n n i i αα=+)()1(n b n b =+ (13)After adaptation only some of the i αare different from zero (called the support vectors). It is easy to implement the kernel Adatron algorithm since )(i x g can be computed locally to each multiplier,provided that the desired response is available in the input file.In fact,the expression for )(i x g resembles the multiplication of an error with an activation,so it can be included in the framework of neural network learning.The Adatron algorithm essentially prunes the RBF network so that its output for testing is given by,))2,(s g n ()(2∑∈--=Nv e c t o r s s p p o r t i i i i i b x x G d x f σα (14)And cost function in error criterion is∑=-12))))(,(t a n h ()((21)(i i t y t d t J (15) Number of PCs as input and step size is selected by checking the average minimum MSE and average classification accuracy; results are shown in Fig 7.Fig.7(a).Variation of Average MSE on training and CV with number of PCs as inputFig.7(b).Variation of Average Classification Accuracy on Testing on Testdata,Training data and CV data with number of PCs as inputFinaly the SVM based classifier is designed with following specifications,Number of Inputs:5; Step Size:0.7Time required per epoch per exemplar:0.693 msNumber of connection weights:264Designed classifier is trained and tested using the similar datasets and results are as shown in Fig.8 and Fig.9F ig.8.Variation of Average Minimum MSE on Testing on Test data,CV data and Training data with number of rows shifted(n)Fig.9.Variation of Average Minimum MSE on Training and CV withvarious groups(3)Classification and Regression Trees(CART)CART induces strictly binary trees through a process of binary recursively partitioning of feature space of a data set. The first phase is called tree building,and the other is tree pruning.Classification tree is developed using XLSTAT-2009.Various methods, measures andmaximum tree depth are checked and results are shown in Fig.10.It is observed that optimum average classification accuracy on testing on test data and CV data is found to be 90.91 and 80 percent,respectively.Fig.10(a).Variation of Average Classification Accuracy on Testing onTest data and CV data with Method and Measure of TreesFig.10(b).Variation of Average Classification Accuracy on Testing onTest data and CV data with Depth of Trees(4) Discriminant AnalysisDiscriminant analysis is a technique for classifying a set of observations into predefined classes.The purpose is to determine the class of an observation based on a set of variables known as predictors or input variables.The model is built based on a set of observations for which the classes are known. Based on the training set,the technique constructs a set of linear functions of the predictors,known as discriminant functions ,such that c x b x b x b L n n ++++=...2211, where the s b 'are discriminant coefficients, the s x 'are the input variables or predictors and c is a constant. Discriminant analysis is done using XLSTAT-2009.Various models are checked and results are shown in Fig.11.It is observed that optimum average classification accuracy on testing on test data and CV data is found to be 91.77 and 80 percent,respectively.Fig.11.Variation of Average Classification Accuracy on Testing on Testdata and CV data with Model of DAIII.NOISE SUSTAINABILITY OF CLASSIFIERSince the proposed classifier is to be used in real time,where measurement noise is anticipated,it is necessary to check the robustness of classifier to noise.To check the robustness,Uniform and Gaussian noise with mean value zero and variance varies from 1 to 20%is introduced in input and output and average classification accuracy on testing data i.e.unseen data is checked.It is seen that SVM based classifier is the most robust classifier in the sense that it can sustain both uniform and Gaussian noise with 14%and 20%variance in input and output, respectively. Results are as shown in Table IG-Gaussian NoiseU-Uniform NoiseIV.RESULTS AND DISCUSSIONIn this paper,the authors evaluated the performance of the developed ANN based classifiers for detection of four fault conditions of three phase induction motor and examined the results.MLP NN,and SVM are optimally designed and after completion of the training,the learned network is tested to detect different types of faults. Similarly step size is varied in SVM and 0.7 step size is found to be optimum. These confirm our idea that the proposed feature selection method based on the PCA can select the most superior features from the original feature set,and therefore,is a powerful feature selection method.Also proposed classifier is enough robust to the noise,in the sense that classifier gives satisfactory results for Uniform and Gaussian noise with 14%variance in input and with 20% variance in parative results are shown in Fig.12 and Table II.parative analysis of various classifier w.r.t.Averageclassification accuracy.TABLE IICOMPARATIVE RESULTS OF NN BASED CLASSIFIERS中文译文基于神经网络技术的三相异步电动机故障诊断摘要：异步电机故障诊断在工业中十分重要，因为需要提高可靠性和降低由于机器故障造成的生产损失。
毕业设计外文--风力异步电动机翻译
Design Study of Doubly-Fed Induction Generatorsfor a 2MW Wind TurbineABSTRACTA design study for a 2 MW commercial wind turbine is presented to illustrate two connectionmethods for a standard doubly-fed induction machine which can extend the low speed range down to 80% slip without an increase in the rating of the power electronic converter. This far exceeds the normal 30% lower limit. The low speed connection is known as induction generator mode and the machine is operated with a short circuited stator winding with all power flow being through the rotor circuit. A two loop cascaded PI control scheme has been designed and tuned for each mode. The purpose of this paper is to present simulation results which illustrate the dynamic performance of the controller for both doubly-fed induction generator connection methods for a 2 MW wind turbine. A simple analysis of the rotor voltage for the doubly-fed connection method is included as this demonstrates the dominant components that need to be considered when designing such advanced control strategies.Keywords: Doubly-fed, Induction generator, Wind turbineLIST OF IMPORTANT SYMBOLSvrdq Direct and quadrature rotor voltageirdq Direct and quadrature rotor currentλsdq Direct and quadrature stator flux linkagePs Stator real powerQs Stator reactive powerpfs Stator power factorTe Torquep Differential operatorLm Magnetising reactanceRr Rotor resistanceLr Rotor reactanceσ Total leakage inductanceωsf Slip frequency‘s’ Stator referred‘s’ Rotor referred‘*’ Reference value1. INTRODUCTIONThere is continuing interest in wind turbines, especially those with a rated power of many megawatts.This popularity is largely driven by both environmental concerns and also the availability of fossil fuels. Legislation to encourage the reduction of the so called carbon footprintis currently in place and so interest in renewables is currently high. Wind turbines are still viewed as a well established technology that has developed from fixed speed wind turbines to the now popular variable speed technology based on doubly-fed induction generators (DFIGs). A DFIG wind turbine is variable speed with the rotor converter being controlled so that the rotor voltage phase and magnitude is adjusted to maintain the optimum torque and the necessary stator power factor [1, 2, 3]. DFIG technology is currently well developed and is commonly used in wind turbines. The stator of a DFIG is directly connected to the grid with a power electronic rotor converter utilised between the rotor winding and the grid. The variable speed range is proportional to the rating of the rotor converter and so by limiting the speed range to ±30% [4, 5, 6, 7] the rotor converter need only be rated for 30% of the total DFIG power whilst enabling full control over the full generator output power. This can result in significant cost savings for the rotor converter [4]. The slip ring connection to the rotor winding however must be maintained for reliable performance.The power – generator speed characteristic shown in figure 1 is fora commercial 2 MWwind turbine. The generator speed varies with wind speed however this relation is set for a specific location. As wind speed, and therefore machine speed, falls the power output of the generator reduces until the wind turbine is switched off when the power extracted from the wind is less than the losses of the generator and converter. An operating mode has been proposed by a wind turbine manufacturer that is claimed to extend the speed range so that at lower speed the power extracted from the wind is greater than the losses in the system and so the system can remain connected. This proposed that the standard doubly-fed (DF) connection is used over the normal DF speed range and the so-called induction generator (IG) mode is used to extend the low speed operation. Previous work has illustrated that IG mode enables the DFIG to operate down to 80% slip [8]. This change in operation is achieved by disconnecting the stator from the grid in DF mode and then short circuiting the stator to enable IG operation. All of the generator power flows through the rotor converter in IG mode. The IG curve is identical to the DF curve for ±30% slip. The estimated IG power extracted from the wind at low speeds is obtained by extrapolating the curve for the DF mode.The reference torque required by both controllers (DF and IG mode) can easily be derived from this curve. The torque – speed data can then be stored in a look-up table so the reference torque is automatically varied with speed.The capability of modern DF wind turbines to vary the reactive power absorbed or generated [6, 9, 10] allows a wind turbine to participate in the reactive power balance of the grid. The reactive power at the grid connection considered in this work is described, for the UK, by the Connection Conditions Section CC.6.3.2 [11] available from the National Grid. The reactive power requirement for a wind farm is defined by figure 2.Point A - MV Ar equivalent for 0.95 leading power factor at rated MWPoint B - MV Ar equivalent for 0.95 lagging power factor at rated MWPoint C - MV Ar -5 % of rated MWPoint D - MV Ar 5 % of rated MWPoint E - MV Ar -12 % of rated MWThe objective of this paper is to investigate the controller performance of DF and IG mode for a 2MW, 690V, 4-pole DFIG using machine parameters provided by the manufacturer. This is further research building on a previous paper which demonstrated the steady-state performance of the twomodes of operation, DF and IG mode [8]. In [8] the authors discussed the steady-state efficiency for both connections. The steady-state performance work illustrated that there were benefits to operating the machine in one connection method as opposed to the other.This paper examines the controllability (i.e. transient performance) of the 2 MW wind turbine. Results of the full dynamic controller (current regulation, decoupling equations and vector control) in both DF mode and IG mode are shown. A detailed analysis of thecomponents that form the rotor voltage over the full operating range in DFIG mode is presented as this enables the dominant control components to be identified. This is particularly important when designing advanced control schemes as an overview over the full operating range can be identified. Simulation models, which have been validated against a 7.5kW laboratory rig [12], are applied to a realistic 2 MW wind turbine to enable conclusions to be made regarding the proposed use of IG mode in a real wind turbine2. CONNECTION METHODSDoubly-fed induction machines are commonly connected as shown in figure 3. The grid side inverter (GSI) is controlled to maintain a fixed dc link voltage with a given power factor at the grid (in our case unity). The rotor side inverter (RSI) is controlled so the maximum energy is extracted from the kinetic energy of the wind whilst enabling the stator power factor to be controlled within the limits of the grid requirements though unity power factor is often desirable. An alternative connection method for a doubly-fed machine is shown in figure 4, here called the induction generator (IG) connection. The stator is disconnected from the grid and is short-circuited. The rotor circuit is unchanged from figure 3. The GSI is controlled as in DF mode. The objective of the RSI is to control the stator flux linkage while extracting the maximum power from the kinetic wind energy.3. CONTROLLER PERFORMANCEA closed loop controller for both DF mode and IG mode has been discussed in prior work [12] but only for a 7.5 kW laboratory test rig. The dynamics of a 2 MW system are somewhat different and are investigated in this paper. The performance of the dynamic controller for both DF and IG mode are shown in this section for a 2 MW wind turbine.3.1. DFIG Mode (T and Q Control)The reference values for the controller in DF mode are torque (see figure 1) and stator reactive power to enable the grid code requirement [11] to be achieved, figure 2. Two speeds are investigated in this section to enable the performance of the controller to be shown both above and below the 20% of rated power limit from the grid code requirements. A nominal generated power of 320 kW is achieved at 1150 rpm (less than 20% of rated power) anda nominal power of 1.25 MW is achieved at 1550 rpm (greater than 20% of the rated power). The reference and actual torque, Te, and stator reactive power, Qs, are shown for both speedsin figure 5.The value of reference torque, Te*, for both speeds is the specific nominal torque for a given speed calculated from figure 1; −2672 Nm for 1150 rpm and −7701 Nm for 1550 rpm. A step of 200 Nm is applied at both speeds to illustrate the dynamic response to a step change in torque. The value of reference stator reactive power, Qs*, at 1150 rpm is varied between the limits specified by the grid code requirements; initially −5% of the generated power with a step at t=3.5s to +5% of the generated power. At 1550 rpm the stator power factor, pfs*, is initially 0.95 leading with a step change at t=3s to unity pfs and a final step at t=4s to a 0.95 lagging pfs. The vector control loops are tuned for a time constant of 0.1s and 0.9s for the Te and the Qs loops respectively. The vector control is designed to have a slower bandwidth than the current regulation.The actual rotor current direct, irds, and quadrature, irqs, components corresponding to figure 5 are shown in figure6. The effect of the step change in Te* is apparent on the irqs (the superscript ‘s’ indicates that the variable is referred to the stator) as expected. The irqs* component at 1550 rpm contains small transient responses at t=3s and t=4s that are due to the step changes in the Qs value. The step change in Qs*, shown in figure 5, causes a fast change in irds*, figure 6, as there is initially an error between the reference and actual Qs as the control takes a short while torespond. The current regulation is tuned to ensure that the bandwidth prevents the controller responding to such transients while still achieving a suitable speed of response.The equation based tuning used to design the controller gives similar values of proportional and integral gains for the current regulation direct and quadrature loops to those used by Holdsworth et al [10].3.2. IG Mode (T and Flux Control)The reference values for the controller in IG mode are stator flux linkage and torque. Two conditions are investigated for the 2 MW generator in IG mode, start-up and torque step responses, at 400 rpm (minimum IG mode speed [12]) and 1420 rpm (generated power at this speed corresponds to the upper power rating of rotor converter, 600 kW). The reference and actual torque, Te, and stator flux linkage, λsr (the superscript ‘r’ indicates that the variable is referred to the rotor), for both speeds are shown in figure 7.The steady-state Te is the nominal value for the speed of operation, −320 Nm for 400 rpm and −4081 Nm for 1420 rpm derived from figure 1. A start-up sequence is required to establish the rated λsr in the machine, for a given speed, by means of a ramp, figure 7, before the machine can generate power.Once the controller reference λsr has been established in the machine, the Te* is increased by means of a controlled ramp to the nominal value for a given speed and then a step response of 50 Nm step at 400 rpm and 200 Nm at 1420 rpm is applied. The controller regulates the machine to track Te* as expected, see figure 7.The vector control loops determine the reference rotor current values that are shown in figure 8. The ird component initially increases rapidly to establish the λsr and is approximately 3 times the nominal steady-state value for a given load point. The current is within the rated limit at all times. The initial ird can be significantly reduced if a slower response of λsr is implemented.The irq component is regulated by the torque loop to enable the desired power to be generated. Initially there is a slight error due to the high ird which affects the quadrature loop by the cross coupling terms. Once nominal λsr is established in the machine the direct and quadrature loops are decoupled. Again a Te step causes a transient spike in irq* though the control is tuned to be slower than this change in reference value.4. CONTRIBUTION OF ROTOR VOLTAGE COMPONENTSThe performance of both DF and IG mode has been illustrated in the previous section. Both controllers are based on an inner current loop and an outer control loop for torque and stator reactive power in the DF case and torque and stator flux linkage in the IG case. Decoupling equations were then added to the PI controller outputs to reduce the effect of cross coupling between the loops. The final part of this work studies the contribution of the steady state components of rotor voltage, given in full in eqns (1 and 2), for a 2 MW machine to assess the importance of decoupling equations at various speeds. The rotor voltage, vrs, rotor current,irs, and the non-differential components of vrs given by eqns (1 and 2) are investigated for the full DF speed range (1000 to 1950 rpm) with the nominal torque determined from figure 1, and a stator power factor, pfs, range of 0.9 lagging to 0.9 leading. Only the pfs is considered as the GSI is assumed to maintain unity pf at the rotor converter connection to the grid independentof the RSI.Figure 9 shows the variation of vrdqs for the speed and stator reactive power range investigated. The vrds component is dominated in the steady-state by the −ωsfσirqs term as the voltage drop across Rrs is negligible and the λsq component is zero due to the choice of reference frame. This can be confirmed by comparing figure 9 with figures 11. The vrqs in a 2 MW machine is dominated by the ωsf(Lm/Ls)λsd term as the low total leakage inductance, σ, reduces the effect of the irds cross coupling term and the λs orientation frame sets the λsq component to zero. The variation in vrqs at constant speed (and therefore torque) is due to the cross coupling from the irds which is regulating the stator reactive power, Qs, and therefore pfs.The vrs magnitude is dominated by the vrqs component and is symmetrical 1500rpm; thesynchronous speed for a 4-pole machine. This is confirmed by Park et al [13].The steady-state variation in the direct, irds, and quadrature, irqs, rotor current components with respect to speed and Qs is shown in figure 10. The irds component regulates the stator power factor, pfs, by controlling Qs and the irds component regulates Te. The value of irds determines the proportion of the generator reactive power supplied by the stator and rotor circuits. An increasingly positive irds increases the proportion of Q from the rotor circuit while decreasing the Q from the stator until Q is exported by the stator. An increasingly negative irds increases the Q from the stator circuit, reducing the Q from the rotor side until Q is exported by the rotor. Qs increases with Te to maintain the desired pfs and so the irds component will be higher for constant pfs at higher speeds. The irqs component is approximately constant at constant speed due to the constant torque and is positive for generated power due to the orientation frame and the direct and quadrature axis alignment.The irs magnitude is within the rated value for all conditions considered in figure 10.The remainder of this section illustrates the rotor voltage, vrdqs, steady-state components from eqns (1 and 2). The Rrsirds term in vrds and the Rrsirqs term in vrqs are simply irdqs, figure 10,scaled by Rrs and so are not shown.The jσωsfirdqs cross coupling terms of vrdqs are shown in figure 11. The jσωsfirqs term contributes to vrds and σωsfirds forms part of vrqs. The σωsfirds component varies with both speed and stator reactive power as stator reactive power is proportional to torque for a given stator power factor. The σωsfirds component increases with speed as the load torque increases,figure 1. The −σωsfirqs component is the dominant term in the vrds component, eqn (1), at non-synchronous speeds; the polarity is a result of ωsf and the magnitude is defined by the torque. The magnitude is irdqs scaled by slip frequency, ωsf, and the total leakage inductance, σ.Figure 12 shows the j(Lm/Ls)ωsfλsdq component of vrdqs. The −(Lm/Ls)ωsfλsq term contributes to vrds; the term is approximately zero due to the orientation frame. The (Lm/Ls)ωsfλsd term dominates the vrqs component. The shape of the (Lm/Ls)ωsfλsd component is clearly influenced by ωsf.5. DISCUSSIONThis analysis enables the vrds and vrqs components to be characterised by the dominant terms. The λs orientation frame results in the λsq feed forward term in vrds being negligible and so the steady state vrds component is a result of Rrsirds−σωsfirqs. Three distinct regions can then be identified, sub-synchronous speed (low irqs due to low load so vrds is approximately Rrsirds), about synchronous speed (ωsf is around 0 so vrds is approximately Rrsirds) and supersynchronous speed (irds and irqs are comparable due to higher load torque and high stator power factor so vrds is approximately Rrsirds−σωsfirqs). The transient response of vrds for a step in irds* is dominated by the pσirds. The p(Lm/Ls)λsd term has a negligible effect as the λsd term is constant assuming a stiff grid. An irds* step affects both the steady state value of vrqs and the steady state terms in vrds.The steady state vrqs component is dominated by the λsd term, confirmed by Hopfensperger et al [9] (with the exception of synchronous speed when the steady state vrqs is dependent on the Rrsirqs term). The transient response of vrqs to an irqs* step is dominated by the pσirqs term as the differential of the step change in irqs is initially high.The p(Lm/Ls)λsq term has a negligible effect as λsq is approximately zero. The vrds term and the steady-state terms in vrqs all experience a change in value due to the irqs* step.6. CONCLUSIONSThis paper has investigated the controller response for the DF and IG mode connections for a 2 MW DFIG wind turbine. The machine parameters for the 2 MW machine were provided, for a commercially available WRIM used in wind turbines, by the manufacturer. The 2 MW machine parameters used in this work are not simply a linear scaling of prior work on a 7.5 kW machine and so the characteristics are not identical between the two machines.Two areas of analysis have been investigated with respect to the 2 MWDFIG.Existingsimulation models have been used to evaluate the controllability and steady-state andtransient behaviour of a 2 MW DFIG in DF and IG mode. The outcome shows that IG mode is a controllable mode of operation which will extend the low speed operation as rotor voltage decreases (as speed reduces) and so the voltage limit of the IGBTs will be respected as will the current and power limits of the machine and converter. The composition of the rotor voltage was investigated in DF mode for the 2 MW DFIG. This showed how the importance of the decoupling equations on the performance of the DFIG varied with speed.REFERENCES1. Pena R, Clare J and Asher GM. Doubly Fed Induction Generator using Back-to-Back PWM Converters and its Application to V ariable-Speed Wind-Energy Generation. IEE Proceedings - Electric Power Applications May 1996; 143; 3; 231–241.2. Kelber C and Schumacher W. Control of Doubly-Fed Induction Machines as an Adjustable Speed Motor/Generator, VSSHy 2000 - European Conference V ariable Speed in Small Hydro.3. Ran L, Bumby JR and Tavner PJ. Use of Turbine Inertia for Power Smoothing of Wind Turbines with a DFIG. 11th International Conference on Harmonics and Quality of Power 2004; 106–111.4. Müller S, Deicke M and De Doncker RW. Doubly fed induction generator systems for wind turbines. IEEE Industry Applications Magazine 2002; May/June; 26–33.5. Hansen AD, Iov F, Blaaberg F and Hansen LH. Review of Contemporary Wind Turbine Concepts and their Market Penetration. Wind Engineering 2004; 28; 3; 247–263.6. Chengwu L and Fengxiang W and Y ong T. Design and Implementation of A Doubly- Fed VSCF Wind Power Control System. International Conference on Power System Technology: PowerCon 2002; 4; 2126–2129.7. Hofmann W. Optimal Reactive Power Splitting in Wind Power Plants Controlled by Double-Fed Induction Generator. IEEE AFRICON September 1999; 2; 943–948.8. Smith S, Todd R, Barnes M and Tavner PJ. Improved Energy Conversion for Doubly-Fed Wind Generators. IEEE Transactions on Industry Applications 2006; 42; 1421–1428.9. Hopfensperger B, Atkinson DJ and Lakin RA. Stator-Flux-Oriented Control of a Doubly- Fed Induction Machine With and Without Position Encoder. IEE Proceedings - Electric Power Applications July 2000; 147; 4; 241–250.10. Holdsworth L, Wu XG, Ekanayake JB and Jenkins N. Comparison of Fixed Speed and Doubly-Fed Induction Wind Turbines During Power System Disturbances. IEE Proceedings - Generation, Transmission and Distribution May 2003; 150; 3; 343–352.11. National Grid, Connection Conditions September 2005; Rev 12; Issue 3.。
机械设计制造及其自动化毕业论文中英文资料外文翻译
机械设计创造及其自动化毕业论文外文文献翻译INTEGRATION OF MACHINERY译文题目专业机械设计创造及其自动化外文资料翻译INTEGRATION OF MACHINERY（From ELECTRICAL AND MACHINERY INDUSTRY）ABSTRACTMachinery was the modern science and technology development inevitable result, this article has summarized the integration of machinery technology basic outline and the development background .Summarized the domestic and foreign integration of machinery technology present situation, has analyzed the integration of machinery technology trend of development.Key word： integration of machinery ，technology， present situation ，product t，echnique of manufacture ，trend of development0. Introduction modern science and technology unceasing development, impelled different discipline intersecting enormously with the seepage, has caused the project domain technological revolution and the transformation .In mechanical engineering domain, because the microelectronic technology and the computer technology rapid development and forms to the mechanical industry seepage the integration of machinery, caused the mechanical industry the technical structure, the product organization, the function and the constitution, the production method and the management systemof by machinery for the characteristic integration ofdevelopment phase.1. Integration of machinery outline integration of machinery is refers in the organization new owner function, the power function, in the information processing function and the control function introduces the electronic technology, unifies the system the mechanism and the computerization design and the software which constitutes always to call. The integration of machinery development also has become one to have until now own system new discipline, not only develops along with the science and technology, but also entrusts with the new content .But its basic characteristic may summarize is: The integration of machinery is embarks from the system viewpoint, synthesis community technologies and so on utilization mechanical technology, microelectronic technology, automatic control technology, computer technology, information technology, sensing observation and control technology, electric power electronic technology, connection technology, information conversion technology as well as software programming technology, according to the system function goal and the optimized organization goal, reasonable disposition and the layout various functions unit, in multi-purpose, high grade, redundant reliable, in the low energy consumption significance realize the specific function value, and causes the overall system optimization the systems engineering technology .From this produces functional system, then becomes an integration of machinery systematic or the integration of machinery product. Therefore, of coveringtechnology is based on the above community technology organic fusion one kind of comprehensive technology, but is not mechanical technical, the microelectronic technology as well as other new technical simple combination, pieces together .This is the integration of machinery and the machinery adds the machinery electrification which the electricity forms in the concept basic difference .The mechanical engineering technology has the merely technical to develop the machinery electrification, still was the traditional machinery, its main function still was replaces with the enlargement physical strength .But after develops the integration of machinery, micro electron installment besides may substitute for certain mechanical parts the original function, but also can entrust with many new functions,like the automatic detection, the automatic reduction information, demonstrate the record, the automatic control and the control automatic diagnosis and the protection automatically and so on .Not only namely the integration of machinery product is human's hand and body extending, human's sense organ and the brains look, has the intellectualized characteristic is the integration of machinery and the machinery electrification distinguishes in the function essence.2. Integration of machinery development condition integration of machinery development may divide into 3 stages roughly.20th century 60's before for the first stage, this stage is called the initial stage .In this time, the people determination not on own initiative uses the electronic technology the preliminary achievement to consummate the mechanical product the performance .Specially in Second World War period, the war has stimulated the mechanical product and the electronic technology union, these mechanical and electrical union military technology, postwar transfers civilly, to postwar economical restoration positive function .Developed and the development at that time generally speaking also is at the spontaneouscondition .Because at that time the electronic technology development not yet achieved certain level, mechanical technical and electronic technology union also not impossible widespread and thorough development, already developed the product was also unable to promote massively. The 20th century 70~80 ages for the second stage, may be called the vigorous development stage .This time, the computer technology, the control technology, the communication development, has laid the technology base for the integration of machinery development . Large-scale, ultra large scale integrated circuit and microcomputer swift and violent development, has provided the full material base for the integration of machinery development .This time characteristic is :①A mechatronics word first generally is accepted in Japan, probably obtains the quite widespread acknowledgment to 1980s last stages in the worldwide scale ;②The integration of machinery technology and the product obtained the enormous development ;③The various countries start to the integration of machinery technology and the product give the very big attention and the support. 1990s later periods, started the integration of machinery technology the new stagewhich makes great strides forward to the intellectualized direction, the integration of machinery enters the thorough development time .At the same time, optics, the communication and so on entered the integration of machinery, processes the technology also zhan to appear tiny in the integration of machinery the foot, appeared the light integration of machinery and the micro integration of machinery and so on the new branch; On the other hand to the integration of machinery system modeling design, the analysis and the integrated method, the integration of machinery discipline system and the trend of development has all conducted the thorough research .At the same time, because the hugeprogress which domains and so on artificial intelligence technology, neural network technology and optical fiber technology obtain, opened the development vast world for the integration of machinery technology .These research, will urge the integration of machinery further to establish the integrity the foundation and forms the integrity gradually the scientific system. Our country is only then starts from the beginning of 1980s in this aspect to study with the application .The State Councilsummary had considered fully on international the influence which and possibly brought from this about the integration of machinery technology developmenttrend .Many universities, colleges and institutes, the development facility and some large and middle scale enterprises have done the massive work to this technical development and the application, does not yield certain result, but and so on the advanced countries compared with Japan still has the suitable disparity.3. Integration of machinery trend of development integrations of machinery are the collection machinery, the electron, optics, the control, the computer, the information and so on the multi-disciplinary overlapping syntheses, its development and the progress rely on and promote the correlation technology development and the progress .Therefore, the integration of machinery main development direction is as follows:3.1 Intellectualized intellectualizations are 21st century integration of machinery technological development important development directions .Theartificial intelligence obtains day by day in the integration of machinery constructor's research takes, the robot and the numerical control engine bedis to the machine behavior description, is in the control theory foundation, the absorption artificial intelligence, the operations research, the computer science, the fuzzy mathematics, the psychology, the physiology and the chaos dynamics and so on the new thought, the new method, simulate the human intelligence, enable it to have abilities and so on judgment inference, logical thinking, independent decision-making, obtains the higher control goal in order to .Indeed, enable the integration of machinery product to have with the human identical intelligence, is not impossible, also is nonessential .But, the high performance, the high speed microprocessor enable the integration of machinery product to have preliminary intelligent or human's partial intelligences, then is completely possible and essential.In the modern manufacture process, the information has become the control manufacture industry the determining factor, moreover is the most active actuation factor .Enhances the manufacture system information-handling capacity to become the modern manufacture science development a key point .As a result of the manufacture system information organization and structure multi-level, makes the information the gain, the integration and the fusion presents draws up the character, information measure multi-dimensional, as well as information organization's multi-level .In the manufacture information structural model, manufacture information uniform restraint, dissemination processing and magnanimous data aspects and so on manufacture knowledge library management, all also wait for further break through.Each kind of artificial intelligence tool and the computation intelligence method promoted the manufacture intelligence development in the manufacture widespread application .A kind based on the biological evolution algorithm computation intelligent agent, in includes thescheduling problem in the combination optimization solution area of technology, receives the more and more universal attention, hopefully completes the combination optimization question when the manufacture the solution speed and the solution precision aspect breaks through the question scale in pairs the restriction .The manufacture intelligence also displays in: The intelligent dispatch, the intelligent design, the intelligent processing, the robot study, the intelligent control, the intelligent craft plan, the intelligent diagnosis and so on are various These question key breakthrough, may form the product innovation the basic research system. Between 2 modern mechanical engineering front science different science overlapping fusion will have the new science accumulation, the economical development and society's progress has had the new request and the expectation to the science and technology, thus will form the front science .The front science also has solved and between the solution scientific question border area .The front science has the obvious time domain, the domain and the dynamic characteristic .The project front science distinguished in the general basic science important characteristic is it has covered the key science and technology question which the project actual appeared.Manufacture system is a complex large-scale system, for satisfies the manufacture system agility, the fast response and fast reorganization ability, must profit from the information science, the life sciences and the social sciences and so on the multi-disciplinary research results, the exploration manufacture system new architecture, the manufacture pattern and the manufacture system effective operational mechanism .Makes the system optimization the organizational structure and the good movement condition is makes the system modeling , the simulation and the optimized essential target .Not only the manufacture system new architecture to makes the enterprise the agility and may reorganize ability to the demand response ability to have the vital significance, moreover to made the enterprise first floor production equipment the flexibility and may dynamic reorganization ability set a higher request .The biological manufacture view more and more many is introduced the manufacture system, satisfies the manufacture system new request.The study organizes and circulates method and technique of complicated system from the biological phenomenon, is a valid exit which will solve many hard nut to cracks that manufacturing industry face from now on currently .Imitating to living what manufacturing point is mimicry living creature organ of from the organization, from match more, from growth with from evolution etc. function structure and circulate mode of a kind of manufacturing system and manufacturing process.The manufacturing drives in the mechanism under, continuously by one's own perfect raise on organizing structure and circulating mode and thus to adapt the process of[with] ability for the environment .For from descend but the last product proceed together a design and make a craft rules the auto of the distance born, produce system of dynamic state reorganization and product and manufacturing the system tend automatically excellent provided theories foundation and carry out acondition .Imitate to living a manufacturing to belong to manufacturing science and life science of"the far good luck is miscellaneous to hand over", it will produce to the manufacturing industry for 21 centuries huge of influence .机电一体化摘要机电一体化是现代科学技术发展的必然结果,本文简述了机电一体化技术的基本概要和发展背景。
电气专业毕业设计外文翻译
附录AA few examples will refresh your memory about the content of Chapter 8 and thegeneral approach to a nodal-analysis solution.EXAMPLE 17.12 Determine the voltage across the inductor for the network of Fig.Solution:Steps 1 and 2 are as ndicated in Fig.17.22.Step 3:Note Fig.17.23 for the application of Kirchhoff ’s current law to node V1:Fig.17.22 Fig.17.23∑Ii=∑I0 0=I1+I2+I3V1-E/Z1+(V1/Z2)+(V1-V2)/Z3=0Rearranging terms: V1[1/Z1+1/Z2+1/Z3]-V2[1/Z3]=E1/Z1 (17.1)Note Fig.17.24 for the application of Kirchhoff ’s current law to node V2:0=I3+I4+IV2-V1/Z3+V2/Z4+I=0Rearranging terms: V2[1/Z3+1/Z4]-V1[1/Z3]=-I (17.2)Fig.17.24Grouping equations: V1[1/Z1+1/Z2+1/Z3]-V2[1/Z3]=E1/Z1V1[1/Z3]-V2[1/Z3+1/Z4] =I1/Z1+1/Z2+1/Z3=1/0.5k Ω+1/10 k Ω+1/2k Ω=2.5mS ∠-2.29°1/Z3+1/Z4=1/2k Ω+1/-5k Ω=0.539mS ∠21.80°and V1[2.5ms ∠-2.29°]-V2[0.5mS ∠0°]=24m Α∠0°V1[0.5mS ∠0°]-V2[0.539mS ∠21.80°]=4m Α∠0°with 24m Α∠0° -0.5mS ∠0°4mΑ∠0°-0.539mS∠21.80°V1= 2.5ms∠-2.29°-0.5mS∠0°0.5mS∠0°-0.539mS∠21.80°=(24mΑ∠0°)(-0.539mS∠21.80°)+(0.5mS∠0°)(4mΑ∠0°)/[(2.5ms∠-2.29°)(-0.539mS∠21.80°)+(0.5mS∠0°)(0.5mS∠0°)]=-10.01ν-j4.81ν/-1.021-j0.45=11.106ν∠-154.33°/1.116∠-156.21°V1=9.95∠1.88°MathCad The length and complexity of the above mathematical development strongly suggest the use of an alternative approach such as MathCad.Note in MathCad 17.2 that the equations are entered in the same format as Eqs.(17.1) and (17.2).Both V1 and V2 were generated,but because only V1 was asked for,it was the only solution converted to the polar form.In the lower solution the complexity was significantly reduced by simply recognizing that the current is in milliamperes and the impedances in kilohms. The result will then be in volts.K :=10³m :=0.01 rad :=1V1 :=1+j V2 :=1+j deg :=π/180GivenV1·[1/5·k+1/10j·k+1/2·k]-V2·1/2·k≈24·mV1·[1/2·k]-V2[1/2·k+1/-5j·k]≈4·mFind(V1,V2)= 9.944 +0.319j Volts1.786 -0.396j VoltsV1 :=9.944+0.319j V1 =9.949 arg(V1)=1.837·degRecognizing that current in mA results ehen Z is in kilohmns,an alternative format follows:GivenV1·[1/5+1/10j+1/2]-V2·1/2≈24V1·1/2-V2[1/2+1/-5j]≈4Find(V1,V2)= 9.944 +0.319j Volts1.786 -0.396j VoltsV1 :=9.944+0.319j V1 =9.949 arg(V1)=1.837·degMATHCAD 17.2Dependent Current Sources For dependent current sources,the procedure is modified as follows:Steps 1 and 2 are the same as those applied for independent sources.Step 3 is modified as follows:Treat each dependent current source like an independent source when Kirchhoff’s current law applied to each defined node.However,once the equations are established,substitute the equation for the controlling quantity to ensure that the unknowns are limited solely to the chosen nodal voltages.1.Step 4 is as before.EXAMPLE 17.13 Write the nodal equations for the network of Fig.17.25 having a dependent current source.Solution: Steps 1 and 2 are as defined in Fig.17.25.Fig.17.25.Step 3: At node V1, I=I1+I2V1/Z1+V1-V2/Z2-I=0and V1[1/Z1+1/Z2]-V2[1/Z2]=IAt node V2, I2+I3+ΚI=0V2-V1/Z2+V2/Z3+Κ[V1-V2/Z2]=0and V1[1-Κ/Z2]-V2[1-Κ/Z2+1/Z3]=0resulting in two equations and two unknowns.Independent Voltage Sources between Assigned Nodes For independent voltage sources between assigned nodes,the procedure is modified as follows:1.Steps 1 and 2 are the same as those applied for independent sources.2.Step 3 is modefied as follows:Treat each source betwwen defined nodes as ashort circuit(recall the supernode classification of Chapter 8),and write the nodal equations for each remaining independent node.Then relate the chosen nodal voltages to the independent voltage source to ensure that the unknowns of the ginal equations are limited solely to the nodal voltages.3.Step 4 is as before.EXAMPLE 17.14 Write the nodal equations for the network of Fig.17.26 having an independent source between two assigned nodes.Solution: Steps 1 and 2 defined in Fig.17.26.Step 3:Replacing the independent source E with a short-circuit equivalent results in a supernode that will generate the following equation when Kirchhoff’s current law is applied to node V1: I1=V1/Z1+V2/Z2+I2with V2-V1=EFig.17.26.and we have two equationsand two unknowns.Dependent Voltage Source between Defined Nodes For dependent voltage sources between defined nodes,the procedure is modified as follows:1.Steps 1 and 2 are the same as those applied for independent voltage sources.2.Step 3 is modified as follows:The procedure is essentially the same as thatapplied for independent voltage sources,except now the dependent sourcess having to be defined in terms of the chosen nodal voltage to ensure that the final equations have only nodal voltage as their unknown quantities.3.Step 4 is as before.EXAMPLE 17.15Write the nodal equations for the network of Fig.17.27 having a dependent voltage source between two defined nodes.Solution: Steps 1 and 2 are defined in Fig.17.27.Fig.17.27.Step 3:Replacing the dependent source μVx with a short-circuit equivalent will result in the following equation when Kirchhoff's current law is applied at node V1:I=I1+I2V1/Z1+(V1-V2)/Z2-I=0and V2=μVx=μ[V1-V2]or V2=μV1/1+μresulting in two equations and two unknowns.Note that because the impedance Z3 is in parallelwith a voltage source,it does not appear in the analysis.It will,however,affect the current through the dependent voltage source.Format ApproachA close examination of Eqs.(17.1) and (17.2) in Example 17.12 will reveal thatthey are the same equations that would have been obtained using the format approach introduce in Chapter 8.Recall that the approach required that the voltage source first be converted to a current source,but the writing of the equations was quite direct and minimized any chances of an error due to lost sign or missing term.The sequence of steps required to apply the format approach is the following:1.Choose a reference node and assign a subscripted voltage lable to the(N-1)remaining independent nodes of the network.2.The number of equations required for a complete solution is equal to the numberof subcripted voltages(N-1).Column 1 of each equation is formed by summing the admittances tied to the node of interest and multiplying the result by that subscripted nodal voltage.3.The mutual terms are always subtracted from the terms of the first column.It ispossible to have more than one mutual term if the nodal voltage of interest has an element in common with more than one other nodal voltage.Each mutual term is product of the mutual admittance and the other nodal voltage tied to that admittance.4.The column to the right of the equality sign is the algebraic sum of the currentsources tied to the node of interest.A current source is assigned a positive sign if it supplies current to a node,and a negative sign if it draws current from the node. Solve resulting simultaneous equations for the desired nodal voltages.The comments offered for mesh analysis regarding independent and dependent sources apply here also.EXAMPLE 17.16Using the format approach to nodal analysis,find the voltage across the 4-Ωresistor in Fig.17.28.Fig.17.28.Solution: Choosing nodes(Fig.17.29) and writing the nodal equations,we have Z1=R=4ΩZ2=jXl=j5ΩZ3=-jXc=-j2ΩFig.17.29V1(Y1+Y2)-V2(Y2)=-I1V2(Y3+Y2)-V1(Y2)=+I2or V1(Y1+Y2)-V2(Y2)=-I1-V1(Y2)+V2(Y3+Y2)=+I2Y1=1/Z1 Y2=1/Z2 Y3=1/Z3Using determinants yields-I1 -Y2+I2 Y2+Y3V1 = =-(Y3+Y2)I1+I2Y2/(Y1+Y2)(Y3+Y2)-Y2Y2Y1+Y2 -Y2-Y2 Y3+Y2=-(Y3+Y2)I1+I2Y2/Y1Y3+Y2Y3+Y1Y2Substituting numerical values,we haveV1=-[(1/-j2Ω)+(1/j5Ω)]6Α∠0°+4Α∠0°(1/j5Ω)/(1/4Ω)(1/-j2Ω)+(1/j5Ω)(1/-j2Ω)+(1/4Ω)(1/j5Ω)=-(+j0.5-j0.2)6∠0°+4∠0°(-j0.2)/(1/j8)+(1/10)+(1/j20)=(-0.3∠90°)(6∠0°)+4∠0°(-j0.2)/j0.125+0.1-j0.05=-1.8∠90°+0.8∠-90°/0.1+j0.075=2.6ν∠-90°/0.125∠36.87°V1=20.80ν∠-126.87°MathCad Using MathCad and the matrix format with the admittance parameters will quickly provide a solution for V1 in Example 17.16,as shown in MathCad 17.3.Z1 :=4 Z2 :=5j Z3 :=-2j rad :=1 deg :=π/180Y := [1/Z1+1/Z2] -1/Z2 I := -6 -1/Z2 [1/Z2+1/Z3] 4I/Y= -12.48 -16.64j Volts8.32 -2.24j VoltsV1 := -12.48 -16.64j V1=20.8 arg(V1)=-126.87·degV2 := 8.32 -2.24j V2=8.616 arg(V2)=-15.068·degMATHCAD 17.3EXAMPLE 17.17 Using the format approach,write the nodal equations for the network of Fig.17.30.Fig.17.30.Solution: The circuit is redrawn in Fig.17.31,whereZ1=R1+jXl1=7Ω+j8ΩE1=20ν∠0°Z3=-jXc=-j10ΩZ2=R2+jXl2=4Ω+j5ΩI1=10Α∠20°Z4=R3=8ΩConverting the voltage source to a current source and choosing nodes,we obtain Fig.17.32.Note the “neat”appearance of the network using the subscripted impedances.Working directly with Fig.17.30would be more difficult and could produce errors.Write the nodal equations: V1(Y1+Y2+Y3)-V2(Y3)=+I2V2(Y3+Y4)-V1(Y3)=+I1Y1=1/Z1 Y2=1/Z2 Y3=1/Z3 Y4=1/Z4 which are rewritten as V1(Y1+Y2+Y3)-V2(Y3)=+I2-V1(Y3)+V2(Y3+Y4)=+I1EXAMPLE 17.18 Write the nodal equations for the network of Fig.17.33.Do not solve.Solution: Choose nodes(Fig.17.34): Z1=R1 Z2=jXl1 Z3=R2-jXc2Z4=-jXc1 Z5=R3 Z6=jXl2 and write the nodal equations: V1(Y1+Y2)-V2(Y2)=+I1V2(Y2+Y3+Y4)-V1(Y2)-V3(Y4)=-I2V3(Y4+Y5+Y6)-V2(Y4)=+I2which are rewritten as V1(Y1+Y2)-V2(Y2)+0=+I1-V1(Y2)+ V2(Y2+Y3+Y4)-V3(Y4)=-I20-V2(Y4)+V3(Y4+Y5+Y6)=+I2Y1=1/R1 Y2=1/jXl1 Y3=1/R2-jXc2 Y4=-1/jXc1 Y5=1/R3 Y6=1/jXl2Fig.17.31Note the symmetry about the diagonal for this example and those preceding it in this section.EXAMPLE 17.19Apply nodal analysis to the network of Fig.17.35.Determine the voltage Vl.Solution: In this case there is no need for a source conversion.The network is redrawn in Fig.17.36 with the chosen nodal voltage and subscripted impedances.Apply the format approach: Y1=1/Z1=1/4kΩ=0.25mS∠0°= G1∠0°Y2=1/Z2=1/1kΩ=1mS∠0°= G1∠0°Y3=1/Z3=1/2kΩ∠90°=0.5mS∠-90°=-j0.5mS=-jBlV1: (Y1+Y2+Y3)V1=-100Iand V1=-100I/Y1+Y2+Y3=-100I/0.25mS+1mS-j0.5mS=-100×10³I/1.25-j0.5=-100×10³I/1.3463∠-21.80°=-74.28×10³I∠21.80°=-74.28×10³I(Vi/1kΩ)∠21.80°V1=Vl=-(74.28Vi)V∠21.80°17.6 BRIDGE NETWORKS(ac)The basic bridge figuration was discussed in some detali in Section 8.11 for dc networks.We now continue to examine bridge networks by considering those that have reactive components and a sinusoidal ac voltage or current applied.We will first analyze various familiar forms of the bridge network using mesh analysis and nodal analysis(the format approach).The balance conditions will be investigated throughout the section.Apply mesh analysis to the network of Fig.17.37.The network is redrawn in Fig.17.38,where Z1=1/Y1=1/G1+jBc=G1/(G1²+Bc ²)-jBc/( G1²+Bc²)Z2=R2 Z3=R3 Z4=R4+jXl Z5=R5Applying the format approach: (Z1+Z3)I1-(Z1)I2-(Z3)I3=EFig.17.32(Z1+Z2+Z5)I2-(Z1)I1-(Z5)I3=0(Z3+Z4+Z5)I3-(Z3)I1-(Z5)I2=0which are rewritten as (Z1+Z3)I1-(Z1)I2-(Z3)I3=E-(Z1)I1+(Z1+Z2+Z5)I2-(Z5)I3=0-(Z3)I1-(Z5)I2+(Z3+Z4+Z5)I3=0Note the symmetry about the diagonal of the above equations.For balabce,Iz5=0Α,andIz5=I2-I3=0From the above equations,Z1+Z3 E -Z3-Z1 0 -Z5-Z3 0 (Z3+Z4+Z5)I2==E(Z1Z3+Z1Z4+Z1Z5+Z3Z5)/ΔZ1+Z3 -Z1 -Z3-Z1 (Z1+Z2+Z5) -Z5-Z3 -Z5 (Z3+Z4+Z5)where Δsignifies the determinant of the denominator(or coefficients).Similarly,I3=E(Z1Z3+Z3Z2+Z1Z5+Z3Z5)/Δand Iz5=I2-I3=E(Z1Z4-Z3Z2)/ΔFor Iz5=0,the following must be satisfied(for a finite Δnot equal to zero):Z1Z1= Iz5=0 (17.3)This condition will be analyzed in greater depth later in this section.举几个例子就刷新你对第8章的内容和一般方法一节点，分析解决内存。
三相异步直流电动机的工作原理英文
Three-phase asynchronous motor principleAs the operating electromotor three-phase asynchronous motor.Three-phase asynchronous motor rotor speed below the speed of a rotating magnetic field, with the rotor winding magnetic field between the relative motion and emfs induced and current, and with magnetic field interact to produce electromagnetic torque, realize the energy transformation. Compared with single phase asynchronous motor, three-phase asynchronous motor operating performance is good, and can save various materials. According to the rotor of the different structure, three-phase asynchronous motor can be divided into the cage type and winding type two kinds. Cage type of rotor asynchronous motor simple structure, reliable operation, light, cheap price, a wide range of applications, its main shortcoming is difficult to control. Winding type three-phase asynchronous motor rotor and stator and the three-phase winding through setting and slip rings, brush with external rheostat connection. Adjust rheostat resistance can improve performance and adjustment of the asynchronism electromotor speed motor. Three-phase asynchronous motor principleWhen the stator winding through into the three-phase ac three-phase symmetric arises when a synchronous speed n1 along the stator and rotor round for space in a clockwise rotation magnetic field. Because of a rotating magnetic field rotating speed to n1, rotor conductor of the static beginning, so the rotor conductor will cut the stator and produce a rotating magnetic field induction emf (induction emf direction DingZe judge with the right hand). Because the child is short circuit loop ends conductor short meet, in the role of the induced emf, will produce the rotor conductor with induction emf direction basic consistent inducedcurrent. The rotor current-carrying conductor at stator magnetic field is the role of the electromagnetic force (the direction of the force with the left hand DingZe judge). The electromagnetic force of the rotor axis electromagnetic torque, drive along the rotor rotating magnetic field rotation direction. Through the above analysis can be summed up the motor principle: when the three-phase motor stator winding (each differ 120 KWH Angle), ventilation with three-phase ac, will produce a rotating magnetic field, the rotating magnetic field cutting rotor winding, and thus to the rotor winding induced current (rotor winding is closed access), load flow of rotor stator conductor under the action of a rotating magnetic field will produce the electromagnetic force, thus in the motor shaft formed on the electromagnetic torque, driving motor rotation, and motor rotation direction and the rotating magnetic field in the same direction.Three-phase asynchronous motor, the failure analysis and processing methodThree-phase asynchronous motor, the failure analysis and processing methodWinding is part of the motor, aging, damp, heating, erosion,foreign bodies, invasion, the impact of the external force can cause damage to the winding, motor overloaded, owe voltage, over voltage, phase lack operation can cause the winding down. Winding fault are generally classified into a shorts-and-opens grounding, winding, wiring errors. Now separately fault phenomena, the causes and inspection methods.A, winding groundedRefers to the winding and close or and chassis insulation failure and cause grounded.1, fault phenomenonChassis charged, control circuit of control, the winding short circuit fever, the motor can not runnormally.2, causesWinding insulation resistance decreased damp ? motor overload running ? harmful gas long-term corrosion ? metal object into the winding insulation ? heavy damage internal around the stator winding insulation damage when touch core at the end of the ? winding touch base ? cover the stator and the rotor caused friction insulation burns ? lead wire insulation damage and shell ? together overvoltage (such as lightning) makes the dielectric breakdown.3. Check method(1) observation. Through the visual winding ends and the line slot insulation thing for any damage and observe the trace of the smoldering form, if it is to take place.(2) a multimeter test. Using a multimeter to low resistance archives check, reading is very small, it is grounded.(3) ZhaoOuBiao method. According to different level choosedifferent ZhaoOuBiao measure each group resistance insulation resistance, if the readings for the zero, the said the winding grounding, but to motor insulation damp or by accident and breakdown, need to judge on the basis of experience, generally speaking pointer in the "0" place without swaying timing, can think it has certain resistance value.(4) try lamp method. If try light, explain winding grounding, ifyou find somewhere with sparks or tails, is it for winding ground fault point. If the light is WeiLiang insulation have grounding breakdown. If the bright lights, but test stick grounded also appears sparks that have not yet winding breakdown, but serious damp. Can also be used in the mouth of the hardwood shell tapping edge, knock to a place, a light one out that current when the broken, then it is take place.(5) current wear and method. Use a pressure regulating transformer, connected to the power source, take place soon fever, insulation things that take place in for smoking. Should pay special attention to small motor shall not more than two times the rated current, for no more than half a minute ? big motor for rated current of 20% to 50% or gradually increase current, to take place just when the smoke immediately without electricity.(6) group eliminated method. To take place in the iron core is inmy heart and burning is better, the burning of the copper wire and iron core melt together. The way is to put a grounding in winding into twoand a half, and repeating the process, finally find out take place.In addition, and high pressure test, CiZhen exploration method, power frequency vibration method, different here in this paper.4. The treatment method(1) the dampness of the windings shall first ground drying, whenthe cooling to 60-70 ℃or so, pour again after insulation varnish drying.(2) at the end of the winding insulation damaged, pick up again in the insulation is located in the treatment, paint, and drying.(3) windings to place in the slot, should be heavy around windingor replace part of the winding components.The last of the ZhaoOuBiao measuring different application, andmeet the technical requirements can.Second, winding short circuitDue to excessive current motor power supply voltage change, too, single phase operation, mechanical bruising, poor insulation damage caused by making moves points between winding circles short circuit, winding short circuit, winding between the short circuit and winding alternate with short circuit.1. The fault phenomenaIon of the magnetic field distribution and synchronous balance and make three not operating electromotor vibration and noise when intensifies, serious when motor can't start, but in the short circuit coils of generates a lot of short-circuit current, lead to coil heating and quickly destroyed.2. The reasonMotor long-term overload, make the insulation aging lose insulation effect ? embedding ?winding insulation damage was caused when the moisture insulation resistance decreased caused the breakdown ? insulation。
本科毕业设计(论文)外文翻译译文
本科毕业设计（论文）外文翻译译文学生姓名：院（系）：油气资源学院专业班级：物探0502指导教师：完成日期：年月日地震驱动评价与发展：以玻利维亚冲积盆地的研究为例起止页码：1099——1108出版日期：NOVEMBER 2005THE LEADING EDGE出版单位：PanYAmericanYEnergyvBuenosYAiresvYArgentinaJPYBLANGYvYBPYExplorationvYHoustonvYUSAJ.C.YCORDOVAandYE.YMARTINEZvYChacoYS.A.vYSantaYCruzvYBolivia 通过整合多种地球物理地质技术，在玻利维亚冲积盆地，我们可以减少许多与白垩纪储集层勘探有关的地质技术风险。
通过对这些远景区进行成功钻探我们可以验证我们的解释。
这些方法包括盆地模拟，联井及地震叠前同时反演，岩石性质及地震属性解释，A VO/A V A,水平地震同相轴，光谱分解。
联合解释能够得到构造和沉积模式的微笑校正。
迄今为止，在新区有七口井已经进行了成功钻探。
基质和区域地质。
Tarija/Chaco盆地的subandean 褶皱和冲断带山麓的中部和南部，部分扩展到玻利维亚的Boomerange地区经历了集中的成功的开采。
许多深大的泥盆纪气田已经被发现，目前正在生产。
另外在山麓发现的规模较小较浅的天然气和凝析气田和大的油田进行价格竞争，如果他们能产出较快的油流而且成本低。
最近发现气田就是这种情况。
接下来，我们赋予Aguja的虚假名字就是为了讲述这些油田的成功例子。
图1 Aguja油田位于玻利维亚中部Chaco盆地的西北角。
基底构造图显示了Isarzama背斜的相对位置。
地层柱状图显示了主要的储集层和源岩。
该油田在Trija和冲积盆地附近的益背斜基底上，该背斜将油田和Ben i盆地分开（图1），圈闭类型是上盘背斜，它存在于连续冲断层上，Aguja有两个主要结构：Aguja中部和Aguja Norte,通过重要的转换压缩断层将较早开发的“Sur”油田分开Yantata Centro结构是一个三路闭合对低角度逆冲断层并伴随有小的摆幅。
机电专业毕业设计外文翻译
1 INTRODUCTION Modular products consist of physically detachable modules that interact to perform their intended functions. Modular design has various product life cycle advantages such as possibly more efficient design process, easier assembly, services and upgrading. In addition, such architectures can also facilitate the creation of product variants for customization by adding, removing or replacing modules. As a concept, modular design has been explored by many researchers such as [I-21. Various design methods have been proposed. The methods of using functional structures for modularization composed modules by grouping the function-related elements together. Erixon proposed to use Quality Function Deployment (QFD) to modularize a product [3]. Gu et al [4] reported an integrated design methodology for modular product design. Kimura et al [5] proposed modular products for inverse manufacturing and product reuse. Lange et al applied modular design to design of a fibre reinforced Product plastic track wheel with very good outcome [6]. design and life cycle engineering was well documented by Alting and Legarth [7]. A comprehensive discussion on general product design, development and modeling can be found in reference [8]. Computers are generally more modularized in comparison with mechanical products. One of the most common module connections in electrical products is the bus architecture. These bus architectures are well documented in terms of their functionality, thus allowing third party expansion modules to be easily developed. Usually, they are also self-configurable in the sense that neither the bus nor the add-on module requires physical modification to operate properly.
毕业设计(论文)外文文献翻译要求
毕业设计（论文）外文文献翻译要求
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教务处
20XX年2月27日
杭州电子科技大学
毕业设计（论文）外文文献翻译
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杭州电子科技大学
毕业设计（论文）外文文献翻译
毕业设计（论文）题
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毕业设计英文 翻译(原文)
编号：毕业设计(论文)外文翻译（原文）院（系）：桂林电子科技大学专业：电子信息工程学生姓名： xx学号： xxxxxxxxxxxxx 指导教师单位：桂林电子科技大学姓名： xxxx职称： xx2014年x月xx日Timing on and off power supplyusesThe switching power supply products are widely used in industrial automation and control, military equipment, scientific equipment, LED lighting, industrial equipment,communications equipment,electrical equipment,instrumentation, medical equipment, semiconductor cooling and heating, air purifiers, electronic refrigerator, LCD monitor, LED lighting, communications equipment, audio-visual products, security, computer chassis, digital products and equipment and other fields.IntroductionWith the rapid development of power electronics technology, power electronics equipment and people's work, the relationship of life become increasingly close, and electronic equipment without reliable power, into the 1980s, computer power and the full realization of the switching power supply, the first to complete the computer Power new generation to enter the switching power supply in the 1990s have entered into a variety of electronic, electrical devices, program-controlled switchboards, communications, electronic testing equipment power control equipment, power supply, etc. have been widely used in switching power supply, but also to promote the rapid development of the switching power supply technology .Switching power supply is the use of modern power electronics technology to control the ratio of the switching transistor to turn on and off to maintain a stable output voltage power supply, switching power supply is generally controlled by pulse width modulation (PWM) ICs and switching devices (MOSFET, BJT) composition. Switching power supply and linear power compared to both the cost and growth with the increase of output power, but the two different growth rates. A power point, linear power supply costs, but higher than the switching power supply. With the development of power electronics technology and innovation, making the switching power supply technology to continue to innovate, the turning points of this cost is increasingly move to the low output power side, the switching power supply provides a broad space for development.The direction of its development is the high-frequency switching power supply, high frequency switching power supply miniaturization, and switching power supply into a wider range of application areas, especially in high-tech fields, and promote the miniaturization of high-tech products, light of. In addition, the development and application of the switching power supply in terms of energy conservation, resource conservation and environmental protection are of great significance.classificationModern switching power supply, there are two: one is the DC switching power supply; the other is the AC switching power supply. Introduces only DC switching power supply and its function is poor power quality of the original eco-power (coarse) - such as mains power or battery power, converted to meet the equipment requirements of high-quality DC voltage (Varitronix) . The core of the DC switching power supply DC / DC converter. DC switching power supply classification is dependent on the classification of DC / DC converter. In other words, the classification of the classification of the DC switching power supply and DC/DC converter is the classification of essentially the same, the DC / DC converter is basically a classification of the DC switching power supply.DC /DC converter between the input and output electrical isolation can be divided into two categories: one is isolated called isolated DC/DC converter; the other is not isolated as non-isolated DC / DC converter.Isolated DC / DC converter can also be classified by the number of active power devices. The single tube of DC / DC converter Forward (Forward), Feedback (Feedback) two. The double-barreled double-barreled DC/ DC converter Forward (Double Transistor Forward Converter), twin-tube feedback (Double Transistor Feedback Converter), Push-Pull (Push the Pull Converter) and half-bridge (Half-Bridge Converter) four. Four DC / DC converter is the full-bridge DC / DC converter (Full-Bridge Converter).Non-isolated DC / DC converter, according to the number of active power devices can be divided into single-tube, double pipe, and four three categories. Single tube to a total of six of the DC / DC converter, step-down (Buck) DC / DC converter, step-up (Boost) DC / DC converters, DC / DC converter, boost buck (Buck Boost) device of Cuk the DC / DC converter, the Zeta DC / DC converter and SEPIC, the DC / DC converter. DC / DC converters, the Buck and Boost type DC / DC converter is the basic buck-boost of Cuk, Zeta, SEPIC, type DC / DC converter is derived from a single tube in this six. The twin-tube cascaded double-barreled boost (buck-boost) DC / DC converter DC / DC converter. Four DC / DC converter is used, the full-bridge DC / DC converter (Full-Bridge Converter).Isolated DC / DC converter input and output electrical isolation is usually transformer to achieve the function of the transformer has a transformer, so conducive to the expansion of the converter output range of applications, but also easy to achieve different voltage output , or a variety of the same voltage output.Power switch voltage and current rating, the converter's output power is usually proportional to the number of switch. The more the number of switch, the greater the output power of the DC / DC converter, four type than the two output power is twice as large,single-tube output power of only four 1/4.A combination of non-isolated converters and isolated converters can be a single converter does not have their own characteristics. Energy transmission points, one-way transmission and two-way transmission of two DC / DC converter. DC / DC converter with bi-directional transmission function, either side of the transmission power from the power of lateral load power from the load-lateral side of the transmission power.DC / DC converter can be divided into self-excited and separately controlled. With the positive feedback signal converter to switch to self-sustaining periodic switching converter, called self-excited converter, such as the the Luo Yeer (Royer,) converter is a typical push-pull self-oscillating converter. Controlled DC / DC converter switching device control signal is generated by specialized external control circuit.the switching power supply.People in the field of switching power supply technology side of the development of power electronic devices, while the development of the switching inverter technology, the two promote each other to promote the switching power supply annual growth rate of more than two digits toward the light, small, thin, low-noise, high reliability, the direction of development of anti-jamming. Switching power supply can be divided into AC / DC and DC / DC two categories, AC / AC DC / AC, such as inverters, DC / DC converter is now modular design technology and production processes at home and abroad have already matured and standardization, and has been recognized by the user, but AC / DC modular, its own characteristics make the modular process, encounter more complex technology and manufacturing process. Hereinafter to illustrate the structure and characteristics of the two types of switching power supply.Self-excited: no external signal source can be self-oscillation, completely self-excited to see it as feedback oscillation circuit of a transformer.Separate excitation: entirely dependent on external sustain oscillations, excited used widely in practical applications. According to the excitation signal structure classification; can be divided into pulse-width-modulated and pulse amplitude modulated two pulse width modulated control the width of the signal is frequency, pulse amplitude modulation control signal amplitude between the same effect are the oscillation frequency to maintain within a certain range to achieve the effect of voltage stability. The winding of the transformer can generally be divided into three types, one group is involved in the oscillation of the primary winding, a group of sustained oscillations in the feedback winding, there is a group of load winding. Such as Shanghai is used in household appliances art technological production of switching power supply, 220V AC bridge rectifier, changing to about 300V DC filter added tothe collector of the switch into the transformer for high frequency oscillation, the feedback winding feedback to the base to maintain the circuit oscillating load winding induction signal, the DC voltage by the rectifier, filter, regulator to provide power to the load. Load winding to provide power at the same time, take up the ability to voltage stability, the principle is the voltage output circuit connected to a voltage sampling device to monitor the output voltage changes, and timely feedback to the oscillator circuit to adjust the oscillation frequency, so as to achieve stable voltage purposes, in order to avoid the interference of the circuit, the feedback voltage back to the oscillator circuit with optocoupler isolation.technology developmentsThe high-frequency switching power supply is the direction of its development, high-frequency switching power supply miniaturization, and switching power supply into the broader field of application, especially in high-tech fields, and promote the development and advancement of the switching power supply, an annual more than two-digit growth rate toward the light, small, thin, low noise, high reliability, the direction of the anti-jamming. Switching power supply can be divided into AC / DC and DC / DC two categories, the DC / DC converter is now modular design technology and production processes at home and abroad have already matured and standardized, and has been recognized by the user, but modular AC / DC, because of its own characteristics makes the modular process, encounter more complex technology and manufacturing process. In addition, the development and application of the switching power supply in terms of energy conservation, resource conservation and environmental protection are of great significance.The switching power supply applications in power electronic devices as diodes, IGBT and MOSFET.SCR switching power supply input rectifier circuit and soft start circuit, a small amount of applications, the GTR drive difficult, low switching frequency, gradually replace the IGBT and MOSFET.Direction of development of the switching power supply is a high-frequency, high reliability, low power, low noise, jamming and modular. Small, thin, and the key technology is the high frequency switching power supply light, so foreign major switching power supply manufacturers have committed to synchronize the development of new intelligent components, in particular, is to improve the secondary rectifier loss, and the power of iron Oxygen materials to increase scientific and technological innovation in order to improve the magnetic properties of high frequency and large magnetic flux density (Bs), and capacitor miniaturization is a key technology. SMT technology allows the switching power supply has made considerable progress, the arrangement of the components in the circuit board on bothsides, to ensure that the light of the switching power supply, a small, thin. High-frequency switching power supply is bound to the traditional PWM switching technology innovation, realization of ZVS, ZCS soft-switching technology has become the mainstream technology of the switching power supply, and a substantial increase in the efficiency of the switching power supply. Indicators for high reliability, switching power supply manufacturers in the United States by reducing the operating current, reducing the junction temperature and other measures to reduce the stress of the device, greatly improve the reliability of products.Modularity is the overall trend of switching power supply, distributed power systems can be composed of modular power supply, can be designed to N +1 redundant power system, and the parallel capacity expansion. For this shortcoming of the switching power supply running noise, separate the pursuit of high frequency noise will also increase, while the use of part of the resonant converter circuit technology to achieve high frequency, in theory, but also reduce noise, but some The practical application of the resonant converter technology, there are still technical problems, it is still a lot of work in this field, so that the technology to be practical.Power electronics technology innovation, switching power supply industry has broad prospects for development. To accelerate the pace of development of the switching power supply industry in China, it must take the road of technological innovation, out of joint production and research development path with Chinese characteristics and contribute to the rapid development of China's national economy.Developments and trends of the switching power supply1955 U.S. Royer (Roger) invented the self-oscillating push-pull transistor single-transformer DC-DC converter is the beginning of the high-frequency conversion control circuit 1957 check race Jen, Sen, invented a self-oscillating push-pull dual transformers, 1964, U.S. scientists canceled frequency transformer in series the idea of switching power supply, the power supply to the size and weight of the decline in a fundamental way. 1969 increased due to the pressure of the high-power silicon transistor, diode reverse recovery time shortened and other components to improve, and finally made a 25-kHz switching power supply.At present, the switching power supply to the small, lightweight and high efficiency characteristics are widely used in a variety of computer-oriented terminal equipment, communications equipment, etc. Almost all electronic equipment is indispensable for a rapid development of today's electronic information industry power mode. Bipolar transistor made of 100kHz, 500kHz power MOS-FET made, though already the practical switching power supply is currently available on the market, but its frequency to be further improved. Toimprove the switching frequency, it is necessary to reduce the switching losses, and to reduce the switching losses, the need for high-speed switch components. However, the switching speed will be affected by the distribution of the charge stored in the inductance and capacitance, or diode circuit to produce a surge or noise. This will not only affect the surrounding electronic equipment, but also greatly reduce the reliability of the power supply itself. Which, in order to prevent the switching Kai - closed the voltage surge, RC or LC buffers can be used, and the current surge can be caused by the diode stored charge of amorphous and other core made of magnetic buffer . However, the high frequency more than 1MHz, the resonant circuit to make the switch on the voltage or current through the switch was a sine wave, which can reduce switching losses, but also to control the occurrence of surges. This switch is called the resonant switch. Of this switching power supply is active, you can, in theory, because in this way do not need to greatly improve the switching speed of the switching losses reduced to zero, and the noise is expected to become one of the high-frequency switching power supply The main ways. At present, many countries in the world are committed to several trillion Hz converter utility.the principle of IntroductionThe switching power supply of the process is quite easy to understand, linear power supplies, power transistors operating in the linear mode and linear power, the PWM switching power supply to the power transistor turns on and off state, in both states, on the power transistor V - security product is very small (conduction, low voltage, large current; shutdown, voltage, current) V oltammetric product / power device is power semiconductor devices on the loss.Compared with the linear power supply, the PWM switching power supply more efficient process is achieved by "chopping", that is cut into the amplitude of the input DC voltage equal to the input voltage amplitude of the pulse voltage. The pulse duty cycle is adjusted by the switching power supply controller. Once the input voltage is cut into the AC square wave, its amplitude through the transformer to raise or lower. Number of groups of output voltage can be increased by increasing the number of primary and secondary windings of the transformer. After the last AC waveform after the rectifier filter the DC output voltage.The main purpose of the controller is to maintain the stability of the output voltage, the course of their work is very similar to the linear form of the controller. That is the function blocks of the controller, the voltage reference and error amplifier can be designed the same as the linear regulator. Their difference lies in the error amplifier output (error voltage) in the drive before the power tube to go through a voltage / pulse-width conversion unit.Switching power supply There are two main ways of working: Forward transformand boost transformation. Although they are all part of the layout difference is small, but the course of their work vary greatly, have advantages in specific applications.the circuit schematicThe so-called switching power supply, as the name implies, is a door, a door power through a closed power to stop by, then what is the door, the switching power supply using SCR, some switch, these two component performance is similar, are relying on the base switch control pole (SCR), coupled with the pulse signal to complete the on and off, the pulse signal is half attentive to control the pole voltage increases, the switch or transistor conduction, the filter output voltage of 300V, 220V rectifier conduction, transmitted through the switching transformer secondary through the transformer to the voltage increase or decrease for each circuit work. Oscillation pulse of negative semi-attentive to the power regulator, base, or SCR control voltage lower than the original set voltage power regulator cut-off, 300V power is off, switch the transformer secondary no voltage, then each circuit The required operating voltage, depends on this secondary road rectifier filter capacitor discharge to maintain. Repeat the process until the next pulse cycle is a half weeks when the signal arrival. This switch transformer is called the high-frequency transformer, because the operating frequency is higher than the 50HZ low frequency. Then promote the pulse of the switch or SCR, which requires the oscillator circuit, we know, the transistor has a characteristic, is the base-emitter voltage is 0.65-0.7V is the zoom state, 0.7V These are the saturated hydraulic conductivity state-0.1V-0.3V in the oscillatory state, then the operating point after a good tune, to rely on the deep negative feedback to generate a negative pressure, so that the oscillating tube onset, the frequency of the oscillating tube capacitor charging and discharging of the length of time from the base to determine the oscillation frequency of the output pulse amplitude, and vice versa on the small, which determines the size of the output voltage of the power regulator. Transformer secondary output voltage regulator, usually switching transformer, single around a set of coils, the voltage at its upper end, as the reference voltage after the rectifier filter, then through the optocoupler, this benchmark voltage return to the base of the oscillating tube pole to adjust the level of the oscillation frequency, if the transformer secondary voltage is increased, the sampling coil output voltage increases, the positive feedback voltage obtained through the optocoupler is also increased, this voltage is applied oscillating tube base, so that oscillation frequency is reduced, played a stable secondary output voltage stability, too small do not have to go into detail, nor it is necessary to understand the fine, such a high-power voltage transformer by switching transmission, separated and after the class returned by sampling the voltage from the opto-coupler pass separated after class, so before the mains voltage, and after the classseparation, which is called cold plate, it is safe, transformers before power is independent, which is called switching power supply.the DC / DC conversionDC / DC converter is a fixed DC voltage transformation into a variable DC voltage, also known as the DC chopper. There are two ways of working chopper, one Ts constant pulse width modulation mode, change the ton (General), the second is the frequency modulation, the same ton to change the Ts, (easy to produce interference). Circuit by the following categories:Buck circuit - the step-down chopper, the average output voltage U0 is less than the input voltage Ui, the same polarity.Boost Circuit - step-up chopper, the average output voltage switching power supply schematic U0 is greater than the input voltage Ui, the same polarity.Buck-Boost circuit - buck or boost chopper, the output average voltage U0 is greater than or less than the input voltage Ui, the opposite polarity, the inductance transmission.Cuk circuit - a buck or boost chopper, the output average voltage U0 is greater than or less than the input voltage Ui, the opposite polarity, capacitance transmission.The above-mentioned non-isolated circuit, the isolation circuit forward circuits, feedback circuit, the half-bridge circuit, the full bridge circuit, push-pull circuit. Today's soft-switching technology makes a qualitative leap in the DC / DC the U.S. VICOR company design and manufacture a variety of ECI soft-switching DC / DC converter, the maximum output power 300W, 600W, 800W, etc., the corresponding power density (6.2 , 10,17) W/cm3 efficiency (80-90)%. A the Japanese Nemic Lambda latest using soft-switching technology, high frequency switching power supply module RM Series, its switching frequency (200 to 300) kHz, power density has reached 27W/cm3 with synchronous rectifier (MOSFETs instead of Schottky diodes ), so that the whole circuit efficiency by up to 90%.AC / DC conversionAC / DC conversion will transform AC to DC, the power flow can be bi-directional power flow by the power flow to load known as the "rectification", referred to as "active inverter power flow returned by the load power. AC / DC converter input 50/60Hz AC due must be rectified, filtered, so the volume is relatively large filter capacitor is essential, while experiencing safety standards (such as UL, CCEE, etc.) and EMC Directive restrictions (such as IEC, FCC, CSA) in the AC input side must be added to the EMC filter and use meets the safety standards of the components, thus limiting the miniaturization of the volume of AC / DC power, In addition, due to internal frequency, high voltage, current switching, making the problem difficult to solve EMC also high demands on the internal high-density mountingcircuit design, for the same reason, the high voltage, high current switch makes power supply loss increases, limiting the AC / DC converter modular process, and therefore must be used to power system optimal design method to make it work efficiency to reach a certain level of satisfaction.AC / DC conversion circuit wiring can be divided into half-wave circuit, full-wave circuit. Press the power phase can be divided into single-phase three-phase, multiphase. Can be divided into a quadrant, two quadrant, three quadrants, four-quadrant circuit work quadrant.he selection of the switching power supplySwitching power supply input on the anti-jamming performance, compared to its circuit structure characteristics (multi-level series), the input disturbances, such as surge voltage is difficult to pass on the stability of the output voltage of the technical indicators and linear power have greater advantages, the output voltage stability up to (0.5)%. Switching power supply module as an integrated power electronic devices should be selected。
毕业设计三相异步电动机外文翻译（精）
毕业设计三相异步电动机外文翻译（精）中文翻译异步电动机具有结构简单、运行可靠、价格低、维护方便等一系列的优点,因此,异步电动机被广泛应用在电力拖动系统中。
尤其是随着电力电子技术的发展和交流调速技术的日益成熟,使得异步电动机在调速性能方面大大提高。
目前,异步电动机的电力拖动已被广泛地应用在各个工业电气自动化领域中。
就三相异步电动机的机械特性出发,主要简述电动机的启动,制动、调速等技术问题。
1 三相异步电动机的机械特性文三相异步电动机的机械特性是指电动机的转速n与电磁转矩Tem 之间的关系。
由于转速n与转差率S有一定的对应关系,所以机械特性也常用Tem=f(s的形式表示。
三相异步电动机的电磁转矩表达式有三种形式,即物理表达式、参数表达式和实用表达式。
物理表达式反映了异步电动机电磁转矩产生的物理本质,说明了电磁转矩是由主磁通和转子有功电流相互作用而产生的。
参数表达式反映了电磁转矩与电源参数及电动机参数之间的关系,利用该式可以方便地分析参数变化对电磁转矩的影响和对各种人为特性的影响。
实用表达式简单、便于记忆,是工程计算中常采用的形式。
电动机的最大转矩和启动转矩是反映电动机的过载能力和启动性能的两个重要指标,最大转矩和启动转矩越大,则电动机的过载能力越强,启动性能越好。
三相异步电动机的机械特性是一条非线性曲线,一般情况下,以最大转矩(或临界转差率为分界点,其线性段为稳定运行区,而非线性段为不稳定运行区。
固有机械特性的线性段属于硬特性,额定工作点的转速略低于同步转速。
人为机械特性曲线的形状可用参数表达式分析得出,分析时关键要抓住最大转矩、临界转差率及启动转矩这三个量随参数的变化规律。
2 三相异步电动机的启动小容量的三相异步电动机可以采用直接启动,容量较大的笼型电动机可以采用降压启动。
降压启动分为定子串接电阻或电抗降压启动、Y-D降压启动和自耦变压器降压启动。
定子串电阻或电机降压启动时,启动电流随电压一次方关系减小,而启动转矩随电压的平方关系减小,它适用于轻载启动。
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毕业设计三相异步电动机外文翻译中文翻译异步电动机具有结构简单、运行可靠、价格低、维护方便等一系列的优点，因此，异步电动机被广泛应用在电力拖动系统中。
特别是随着电力电子技术的发展和交流调速技术的日益成熟，使得异步电动机在调速性能方面大大提高。
当前，异步电动机的电力拖动已被广泛地应用在各个工业电气自动化领域中。
就三相异步电动机的机械特性出发，主要简述电动机的启动，制动、调速等技术问题。
1 三相异步电动机的机械特性文三相异步电动机的机械特性是指电动机的转速n与电磁转矩Tem之间的关系。
由于转速n与转差率S有一定的对应关系，因此机械特性也常见Tem＝f（s）的形式表示。
三相异步电动机的电磁转矩表示式有三种形式，即物理表示式、参数表示式和实用表示式。
物理表示式反映了异步电动机电磁转矩产生的物理本质，说明了电磁转矩是由主磁通和转子有功电流相互作用而产生的。
参数表示式反映了电磁转矩与电源参数及电动机参数之间的关系，利用该式能够方便地分析参数变化对电磁转矩的影响和对各种人为特性的影响。
实用表示式简单、便于记忆，是工程计算中常采用的形式。
电动机的最大转矩和启动转矩是反映电动机的过载能力和启动性能的两个重要指标，最大转矩和启动转矩越大，则电动机的过载能力越强，启动性能越好。
三相异步电动机的机械特性是一条非线性曲线，一般情况下，以最大转矩（或临界转差率）为分界点，其线性段为稳定运行区，而非线性段为不稳定运行区。
固有机械特性的线性段属于硬特性，额定工作点的转速略低于同步转速。
人为机械特性曲线的形状可用参数表示式分析得出，分析时关键要抓住最大转矩、临界转差率及启动转矩这三个量随参数的变化规律。
2 三相异步电动机的启动小容量的三相异步电动机能够采用直接启动，容量较大的笼型电动机能够采用降压启动。
降压启动分为定子串接电阻或电抗降压启动、Y-D降压启动和自耦变压器降压启动。
定子串电阻或电机降压启动时，启动电流随电压一次方关系减小，而启动转矩随电压的平方关系减小，它适用于轻载启动。
Y-D降压启动只适用于正常运行时为三角形联结的电动机，其启动电流和启动转矩均降为直接启动时的1/3，它也适用于轻载启动。
自耦变压器降压启动时，启动电流和启动转矩均降为直接启动时的l/k2（k为自耦变压器的变比），适合带较大的负载启动。
绕线转子异步电动机可采用转子串接电阻或频敏变阻器启动，其启动转矩大、启动电流小，适用于中、大型异步电动机的重载启动。
软启动器是一种集电机软启动、软停车、轻载节能和多种保护功能于一体的新型电动机控制装置，国外称为Soft Starter。
它的主要构成是串接于电源与被控电动机之间的三相反并联晶闸管及其电子控制电路。
运用串接于电源与被控电动机之间的软启动器，以不同的方法，控制其内部晶闸管的导通角，使电动机输入电压从零以预设函数关系逐渐上升，直至启动结束，赋予电动机全电压，即为软启动。
在软启动过程中，电动机启动转矩逐渐增加，转速也逐渐增加。
软启动器实际上是个调压器，用于电动机启动时，输出只改变电压并没有改变频率。
3 三相异步电动机的调速三相异步电动机的调速方法有变极调速、变频调速和变转差率调速。
其中变转差率调速包括绕线转子异步电动机的转子串接电阻调速、串级调速和降压调速。
变极调速是经过改变定子绕组接线方式来改变电机极数，从而实现电机转速的变化。
变极调速为有级调速，变极调速时的定子绕组联结方式有三种：Y-YY、顺串Y-反串Y、D-YY。
其中Y-YY联结方式属于恒转矩调速方式，另外两种属于恒功率调速方式。
变极调速时，应同时对调定子两相接线，这样才能保证调速后电动机的转向不变。
变频调速是现代交流调速技术的主要方向，它可实现无级调速，适用于恒转矩和恒功率负载。
绕线转子电动机的转子串接电阻调速方法简单，易于实现，但调速是有级的，不平滑，且低速时特性软，转速稳定性差，同时转子铜损耗大，电动机的效率低。
串级调速克服了转子串接电阻调速的缺点，但设备要复杂得多。
异步电动机的降压调速主要用于风机类负载的场合，或高转差率的电动机上，同时应采用速度负反馈的闭环控制系统。
把电压和频率固定不变的工频交流电变换为电压或频率可变的交流电的装置称作“变频器”。
为了产生可变的电压和频率，该设备首先要把电源的交流电变换为直流电（DC），这个过程叫整流。
再把直流电（DC）变换为交流电（AC），这个过程叫逆变，把直流电变换为交流电的装置叫逆变器（inverter）。
对于逆变为频率可调、电压可调的逆变器我们称为变频器。
变频器输出的波形是模拟正弦波，主要用在三相异步动机的调速，又叫变频调速器。
附录二外文原文Asynchronous motor has a simple structure, reliable operation, low price, convenient maintenance and a series of advantages, therefore, asynchronous motor is widely used in electric drive system. Especially with the development of power electronic technology and AC drive technology becomes more mature, greatly improve the speed performance makes the asynchronous motor. At present, electric drive asynchronous motor has been widely used in various industrial electrical automation. The mechanical properties of three-phase asynchronous motor starting, the main motor starting, braking, speed control technology.The mechanical properties of 1 three-phase asynchronous motorMechanical characteristics of three-phase asynchronous motor is refers to the relationship between the speed of the motor electromagnetic torque of N and Tem. Due to the speed of N and slip S have a certain relationship, so the mechanical properties are also commonly used Tem = f (s) representation. Electromagnetic torque expression of three-phase asynchronous motor has three forms, namely physical expression, parameters and practical expression. Physical expressions reflect the physical nature of electromagnetic torque ofasynchronous motor, the electromagnetic torque is generated by the main flux and rotor active current interaction. Parameter expression reflects the relationship between parameters of electromagnetic torque and power supply parameters and motor, the expression can be used to influence easily analyze the influence of parameter variation on the electromagnetic torque and all kinds of human characteristics. Practical expressions in a simple, easy to remember, is often used in engineering calculation in the form of.The maximum torque of motor and torque are two important indexes reflecting the overload capacity of the motor and starting performance, maximum torque and start torque motor overload capacity is bigger, stronger, better starting performance.The mechanical characteristic of three-phase asynchronous motor is a nonlinear curve, under normal circumstances, with the maximal torque (or critical slip) as a cutoff point, the linear segment for the stable operation region, while the nonlinear section is not stable operating region. Hard characteristic is linear segment inherent mechanical properties, the nominal operating point speed slightly lower than the synchronous speed. Shape parameters available expressions man-made mechanical characteristic curve analysis, analysis the key to grasp the maximum torque, starting torque variation of critical slip and the three with the parameters of.。