毕业设计三相异步电动机外文翻译(精)

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。

河南理工大学HENAN POLYTECHNIC UNIVERSITY英文文献翻译En glish literature tran slati on学院：电气工程与自动化学院专业班级：___________ 电气11-4班_______ 姓名： __________________ 宋家鹏_______ 学号：311008001120 __________ 扌旨导老师：____________ 汪旭东_______2014年6月5日河南理工大学HENAN POLYTECHNIC UNIVERSITY2.5 对称三相电路在这一部分，我们介绍三相对称电路的一下几个话题：丫连接,相电压，线电压，线电流，△形连接负荷，△ - Y变换，以及等效的相图。

c Ca Ab B图2-10三相Y连接电源带Y连接对称负荷电路图对称Y连接图2-10显示的是一个三相Y连接电源带Y连接对称负荷电路图。

对于Y连接电路，每个相的中性点是连接起来的。

在图2-10中电源中性点标记的是n,而负载中性点标记的是N。

把三相电源假设为理想电源，即阻抗忽略不计。

同时，电源和负载之间线路阻抗，中性点n与N之间的线路阻抗也可忽略不计。

三相负荷是对称的，意味着三相之中任意两相间的阻抗是相同的。

对称相电压在图2-10中,三相电源的终端呗标记为a、b、c,电源相电压标记为E an ,E bn，E cn，当电源的三相电压有相同的幅度，任意两相之间互差120度角时，电源是对称的。

当以E an 作为参考相量时，相电压的幅值是10V，对称三相相电压如下所示：E an=10 0E bn10 120 10 240 (2.5.1 )E cn10 120 10 240河南理工大学HENAN POLYTECHNIC UNIVERSITY图2-11以E an 作为参考的对称正序相电压向量图当E an 超前E bn 120度，E bn 超前E cn 以120度角时，此时的相序称为正相序或 者abc 相序。

本科生毕业设计（论文）开题报告题目：三相异步电动机的设计及优化（Y160M-4 11kW）学院：信息工程学院系自动化系专业：XXXXXXXXXXXXXXXXXXXX班级：XXX学号：XXX姓名：XXX指导教师：XXX填表日期：2010 年03 月10 日一、选题的依据及意义电能适宜于大量生产、集中管理、远距离运输和自动控制，比其他各种形式的能两更有优越性。

人类对能量利用和控制的能力决定着社会的生产潜能，从而又影响着人类生活方式的进步。

目前，全球每年电能的用量大约为10^4kW·h，并且还在以每年10亿kw·h的速度增长。

电机是将电能从最初的能源形式转换过来的重要桥梁，又是再将大部分电能转换为机械能的装置。

电机在电力工业、工矿企业、农业、交通运输业、国防、科学文化及日常生活等方面都是十分重要的设备。

在电力工业中，将机械能装换为电能的发电机以及将电网电压升高或降低的变压器，都是电力系统中的关键设备。

在很多地方都需要不同特性的电机来驱动和控制。

随着工业企业电气化、自动化、电脑化的发展，还需要众多的各种容量的精密控制电机，作为整个自动控制系统中的重要元件。

电机行业是一个传统的行业。

经过200多年的发展，它已经成为现代生产、生活中不可或缺的核心、基础，是国民经济中重要的一环。

作为劳动密集型产业，我国发展电机制造业有着得天独厚的优势。

到目前为止，我国的电机制造业已经具有一定规模。

统计数据显示，2008年上半年，全行业实现工业总产值180.5亿元，同比增长19.7%。

累计产量6805万千瓦，同比增长11.1%。

在总产量中，大中型电机产量为2878.7万千瓦，增速减缓3.5个百分点；小型交流电机产量为3224.8万千瓦，同比增长5.6%，增速同比减缓8.8个百分点；直流电机产量284.2万千瓦，同比降低20.9%，增速同比减缓21.7个百分点。

上半年全行业实现销售收入178.5亿元，同比增长17.7%。

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.。

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。

摘要随着电机控制技术的不断发展,在实际中应用越来越多的交流调速系统已经取代了直流调速系统。

由于异步电机是一种复杂的多变量的、强耦合的非线性系统,所以利用计算机仿真的办法构造一个实验系统进行异步电机的分析是一种很好的研究手段。

本文主要首先介绍三相异步牵引电动机结构和构造建立电机数学、物理模型，对比直流电机电磁转矩和异步电动机电磁转矩，结合矢量控制的基本思想和基本概念，完成了对三相交流异步牵引电动机在三相静止坐标和两相静止坐标系上的数学模型，经过坐标转换得到交流牵引电机的模型。

然后通过Matlab/Simulink的模块简化搭建功能完成三相异步牵引电动机最终的仿真模型，并在Mutlab系统环境下实现对电动机的仿真，观察异步电机空载转矩和负载转矩过程中的电流、转速、转矩的变化，对结果与理论结果进行比对分析，证实了该方法的简便直观、高效快捷和真实准确性。

关键词：异步电机；建模；仿真；坐标变换；AbstractWith the development of motor control technology, AC drive system is used more and more in practice has replaced the DC speed regulating system. The asynchronous motor is a strongly coupled nonlinear system is a complex multivariable, using the way of constructing, analysis and computer simulation of an experimental system of asynchronous motor is a very good research tools.This paper first introduces the structure and the structure of three phase a synchronous traction motor mathematical, physical model of motor, compared with DC motor electromagnetic torque and asynchronous motor electro magnetic torque, combined with the basic theory of vector control and the basic concept,the mathematical model in the three-phase static coordinate and two-phase static coordinate system on the three phase asynchronous traction motor, the AC traction the motor model to get the coordinate conversion. Then through the Matlab/Simulink module to simplify the building function to finish the simulation model of the three-phase asynchronous traction motor end, and realize the simulation of the motor in the environment of Mutlab system, variable current,speed, torque of asynchronous motor load torque and load torque in the process, the results were compared with the theoretical results and analysis,confirmed this method simple and intuitive, fast and accurate.KeyWords: Induction motor, Modeling, Simulation, Coordinate transformation目录摘要 (I)Abstract .............................................................................................................................. I I 目录.. (III)1 绪论 (1)1.1研究背景及意义 (1)1.2 国内外研究现状 (1)1.3本论文研究的主要内容 (1)2三相异步电机的构造和工作原理 (2)2.1 三相异步电机的结构和原理 (2)2.1.1三相异步电机的结构 (2)2.1.2三相异步牵引电机工作原理 (2)2.2 三相异步电机的数学模型 (2)2.2.1 三相异步电机在两相静止坐标系上的数学模型 (2)2.2.2 三相异步电机在三相静止坐标系上的数学模型 (3)3 三相牵引电机的建模和仿真 (5)3.1 三相异步牵引电动机模型 (5)3.1.1模型坐标变换 (5)3.1.2建立模型 (5)3.1.3建立s函数以及电机模型 (7)4 仿真结果及其分析 (11)4.1三相输入电流在不同坐标上的波形图 (11)4.2 三相输入电压子在同一坐标下的波形图 (11)4.3 电动机理论输出波形 (12)4.5结果分析 (13)4.6总结 (13)致谢 (14)参考文献 (15)1 绪论1.1 研究背景及意义由于直流调速的局限性和交流调速的优越性,交流异步电动机在实际的需求下得到了很大的发展。

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。

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。

南京理工大学紫金学院毕业设计（论文）外文资料翻译系：机械系专业：车辆工程专业姓名:宋磊春学号:070102234外文出处：EDU_E_CAT_VBA_FF_V5R9(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CATIA V5 的自动化CATIA V5的自动化和脚本：在NT 和Unix上：脚本允许你用宏指令以非常简单的方式计划CATIA。

CATIA 使用在MS –VBScript中(V5.x中在NT和UNIX3。

0 )的共用部分来使得在两个平台上运行相同的宏。

在NT 平台上：自动化允许CATIA像Word/Excel或者Visual Basic程序那样与其他外用分享目标。

ATIA 能使用Word/Excel对象就像Word/Excel能使用CATIA 对象。

在Unix 平台上:CATIA将来的版本将允许从Java分享它的对象。

这将提供在Unix 和NT 之间的一个完美兼容。

CATIA V5 自动化：介绍（仅限NT）自动化允许在几个进程之间的联系:CATIA V5 在NT 上：接口COM：Visual Basic 脚本(对宏来说)，Visual Basic 为应用（适合前:Word/Excel )，Visual Basic。

COM（零部件目标模型)是“微软“标准于几个应用程序之间的共享对象。

Automation 是一种“微软“技术,它使用一种解释环境中的COM对象。

ActiveX 组成部分是“微软“标准于几个应用程序之间的共享对象,即使在解释环境里。

OLE（对象的链接与嵌入）意思是资料可以在一个其他应用OLE的资料里连结并且可以被编辑的方法(在适当的位置编辑）.在VBScript,VBA和Visual Basic之间的差别：Visual Basic(VB）是全部的版本。

它能产生独立的计划,它也能建立ActiveX 和服务器。

它可以被编辑。

VB中提供了一个补充文件名为“在线丛书“(VB的5。

可编辑修改毕业设计题目： 30KW出口三相异步电动机的设计精品文档河北科技大学毕业设计成绩评定表目录1 引言 (1)1.1 三相感应电机概述 (1)1.2 国内外电机制造工业发展状况 (2)1.3 出口电机 (2)2 毕业设计课题任务及设计过程 (4)2.1 课题设计任务内容及要求 (4)2.2 设计过程 (4)2.3电磁计算程序 (7)3.1 VB简介 (30)3.2 程序说明 (31)3.3 设计方法 (31)3.4 程序流程图 (34)3.5 计算程序及计算结果 (37)3.6 方案比较及优选 (51)3.7 程序变量对照表 (55)结论 (59)致谢 (60)附图1 定子冲片图附图2 转子冲片、端环图附图3 绕组展开图副本计算机辅助设计1引言电机在国民经济中发挥着巨大的作用，它是一种能把能量或信号进行转换的电磁装置，现已广泛应用于电力工业、机械行业、交通运输等国民经济的各个领域。

从能量转换的角度来看，电机可分为两大类。

第一类是发电机，它把机械能转换为电能，首先通过原动机先把各类一次能源蕴藏的能量转换为机械能，然后通过发电机把机械能转换为电能，再经输配电线路供给用户使用。

第二类是电动机，它把电能转换为机械能，用来驱动各种用途的生产机械和其他装置，以满足人们不同的需求。

本次设计的电机为电动机，根据所应用的场合和电源的不同，电动机有直流电动机、交流同步电动机、交流感应电动机，以及满足不同需求的特种电动机]1[。

三相异步电动机是电动机的一种，它是人们常用的动力工具，广泛应用于各个领域，它结构简单，制造、使用、维护方便，价格便宜，运行可靠，效率较高，具有直流电机所不具有的优势。

随着电机产品国外市场的进一步拓宽，中小型电机在出口数量、品种、产品档次、创汇额上将会有重大突破]2[。

未来出口电机产量增长主要外部原因在于世界经济稳定增长，促进了行业贸易产量的增长。

内因是国内出口退税率改革导致企业加快出口步伐，及国内外资企业规模的不断扩大和数量的快速增加，产品竞争提高，在国内形成巨大的效益，也刺激了出口上升]3[。

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。

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。

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.。

毕业设计(论文)外文资料翻译学院：机械工程学院专业：机械设计制造及其自动化姓名：崔涛学号： 090501614外文出处： Robotics and Computer-IntegratedManufacturing 25 (2009) 73-80 附件： 1.外文资料翻译译文；2.外文原文。

附件1：外文资料翻译译文科学指南机器人和计算机集成制造25（2009）73–80一个外旋轮线专用的固定循环数控铣床Sotiris L. Omirou a, , Andreas C. Nearchou b——弗雷德里克大学机械工程系，尼科西亚，塞浦路斯，塞浦路斯——希腊帕特雷大学工商管理系发表于2006年9月20日，修改更新从2007年7月23日到2007年9月10日。

摘要提出了一个加工外旋轮线边界的特定的铣床组策略，该方法适用于被集成到一个控制器的数控铣床，对于旋转式内燃发动机（汪克尔），旋转活塞泵和一般外旋轮线形外壳的加工设计特别有用。

方案可以提供较高的精度，其中铣机是通过利用数控插补算法实现的，表面质量控制，是通过粗加工和精加工来实现，整个加工任务可以被编程在一块。

最后，该方法的有效性通过仿真试验验证所产生的刀具路径来实现。

关键词：数控；程序加工；刀具路径生成；偏移曲线；外旋轮线1介绍智能周期提供了一种数控机床来完成重复使用的G / M代码语言的新的加工操作的编程方法。

从本质上讲，智能周期是一个指令被预先设定并永久存储的集机控制器。

它们的使用，消除了许多编程的繁琐需要，减少了编程时间，并简化了整个编程过程。

所有数控加工控制是智能的，这些固定循环可以执行一定的代码，输入任何所需的变量信息。

钻，反钻，深孔钻或槽的加工是标准智能循环应用的例子。

然而，标准智能循环在数量和能力有限，无法容纳复杂的几何形状的日益增加的应用需求。

在加工一个外旋轮线构造特征的情况下，不能用标准智能循环处理。

尽管有其重要的加工应用，现代数控系统仍缺乏类似的专用智能周期。

毕业设计（论文)外文资料翻译系别：专业：班级:姓名：学号:外文出处:附件： 1. 原文; 2。

译文2013年03月附件一：A Rapidly Deployable Manipulator SystemChristiaan J。

J。

Paredis, H. Benjamin Brown，Pradeep K. KhoslaAbstract:A rapidly deployable manipulator system combines the flexibility of reconfigurable modular hardware with modular programming tools，allowing the user to rapidly create a manipulator which is custom-tailored for a given task. This article describes two main aspects of such a system，namely，the Reconfigurable Modular Manipulator System （RMMS)hardware and the corresponding control software。

1 IntroductionRobot manipulators can be easily reprogrammed to perform different tasks, yet the range of tasks that can be performed by a manipulator is limited by mechanicalstructure。

Forexample，a manipulator well-suited for precise movement across the top of a table would probably no be capable of lifting heavy objects in the vertical direction. Therefore，to perform a given task,one needs to choose a manipulator with an appropriate mechanical structure.We propose the concept of a rapidly deployable manipulator system to address the above mentioned shortcomings of fixed configuration manipulators。

外文文献及翻译--三相异步电动机的几种调速方式三相异步电动机的几种调速方式三相异步电动机的转速公式为：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。

从调速的本质来看，不同的调速方式无非是改变交流电动机的同步转速或不改变同步转两种。

在生产机械中广泛使用不改变同步转速的调速方法有绕线式电动机的转子串电阻调速、斩波调速、串级调速以及应用电磁转差离合器、液力偶合器、油膜离合器等调速。

改变同步转速的有改变定子极对数的多速电动机，改变定子电压、频率的变频调速有能无换向电动机调速等。

从调速时的能耗观点来看，有高效调速方法与低效调速方法两种：高效调速指时转差率不变，因此无转差损耗，如多速电动机、变频调速以及能将转差损耗回收的调速方法（如串级调速等）。

有转差损耗的调速方法属低效调速，如转子串电阻调速方法，能量就损耗在转子回路中；电磁离合器的调速方法，能量损耗在离合器线圈中；液力偶合器调速，能量损耗在液力偶合器的油中。

一般来说转差损耗随调速范围扩大而增加，如果调速范围不大，能量损耗是很小的。

一、变极对数调速方法这种调速方法是用改变定子绕组的接红方式来改变笼型电动机定子极对数达到调速目的，特点如下：1、具有较硬的机械特性，稳定性良好；2、无转差损耗，效率高；3、接线简单、控制方便、价格低；4、有级调速，级差较大，不能获得平滑调速；5、可以与调压调速、电磁转差离合器配合使用，获得较高效率的平滑调速特性。

本方法适用于不需要无级调速的生产机械，如金属切削机床、升降机、起重设备、风机、水泵等。

二、变频调速方法变频调速是改变电动机定子电源的频率，从而改变其同步转速的调速方法。

变频调速系统主要设备是提供变频电源的变频器，变频器可分成交流－直流－交流变频器和交流－交流变频器两大类，目前国内大都使用交－直－交变频器。

其特点：1、效率高，调速过程中没有附加损耗；2、应用范围广，可用于笼型异步电动机；3、调速范围大，特性硬，精度高；4、技术复杂，造价高，维护检修困难。

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。

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）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。