内容简介：: 景德镇陶瓷学院科技艺术学院毕业设计(论文)有关外文翻译院系：工程系专业：机械设计制造及自动化姓名：孙松江学号： 201130454105 指导教师：胡伟文完成时间： 2015年5月22日说明1、将与课题有关的专业外文翻译成中文是毕业设计（论文）中的一个不可缺少的环节。此环节是培养学生阅读专业外文和检验学生专业外文阅读能力的一个重要环节。通过此环节进一步提高学生阅读专业外文的能力以及使用外文资料为毕业设计服务，并为今后科研工作打下扎实的基础。2、要求学生查阅与课题相关的外文文献3篇以上作为课题参考文献，并将其中1篇（不少于3000字）的外文翻译成中文。中文的排版按后面格式进行填写。外文内容是否与课题有关由指导教师把关，外文原文附在后面。3、指导教师应将此外文翻译格式文件电子版拷给所指导的学生，统一按照此排版格式进行填写，完成后打印出来。4、请将封面、译文与外文原文装订成册。5、此环节在开题后毕业设计完成前完成。6、指导教师应从查阅的外文文献与课题紧密相关性、翻译的准确性、是否通顺以及格式是否规范等方面去进行评价。指导教师评语：签名：年月日景德镇陶瓷学院科技艺术学院本科毕业设计（论文）外文翻译直流电机速度控制外文翻译 Speed Control of DC Motor1 Regulating systemControl system is a kind of usually offer a stable output power system.For example, motor speed regulator can load torque changes in can still keep motor speed for a constant value. Even if the load torque is zero, motor must also provide enough torque to overcome bearing viscous friction effects. Other types of regulator also provide power output, temperature regulator must be kept inside the furnace temperature constant, that is, even inside the furnace temperature and heat loss must be kept constant. A voltage regulator must also keep load current value change output voltage constant. For any provide an output, such as speed, temperature, voltage of the system, in steady state exist a error signal.2 Electric brakingIn many speed control system, e.g., rolling mills mine winders, etc., the load has to be frequently brought to a standstill and reversed. The rate at which the speed reduces following a reduced speed demand is dependent on the stored energy and the braking system used. A small speed control system (sometimes known as a velodyne) can employ mechanical braking, but this is not feasible with large speed controllers since it is difficult and costly to remove the heat generated. The various methods of electrical braking avaiable are:(1) Regenerative braking.(2) Eddy current braking.(3) Dynamic braking.(4) Reverse current braking(plugging).Regenerative braking is the best method, though not necessarily the most economic. The stored energy in the load is converted into electrical energy by the work motor(acting temporarily as a generator) and is returned to the power supply system. The supply system thus acts as a “sink” into which the unwanted energy is delivered. Providing the supply system has adequate capacity, the consequent rise in terminal voltage will be small during the short periods of regeneration. In the Ward-Leonard method of speed control of DC motors, regenerative braking is inherent, but thyristor drives have to be arranged to invert to regenerate. Induction motor driver can regenerate if the rotor shaft is driven faster than speed of the rotating field. The advent of low-cost variable variable-frequency supplies from thyristor inverters have brought about considerable charges in the use of induction motors in variable speed drives. Eddy current braking can be applied to any machine, simply by mounting a copper or aluminium disc on the shaft and rotating it in a magnetic field. The problem of removing the heat generated is severe in large system as the temperature of the shaft, bearing, and motor will be raised if prolonged braking is applied.In dynamic breaking, the stored energy is a resistor in the circuit. When applied to small DC machines, the armature supply is disconnected and a resistor is connected across the armature (usually by a relay, contactor, or thyristor). The field voltage is maintained, and braking is applied down to the lowest speed. Induction motors require a somewhat more complex arrangement, the stator windings being disconnected from the AC supply and reconnected to a DC supply. The electrical energy generated is then dissipated in the rotor circuit. Dynamic braking is applied to many large AC hoist system where the braking duty is both severe and prolonged. Any electrical motor can be brought to a standstill by suddenly reconnecting the supply to reverse the direction of rotation (reverse current braking). Applied under controlled conditions, this method of braking is satisfactory for all drivers. Its major disadvantage is that the electrical energy consumed by the machine when braking is equal to the stored energy in the load. This increases the running cost significantly in large drives.3 Equal pulse width PWM law VVVF (Variable Voltage Variable Frequency) installs in the early time is uses PAM (Pulse Amplitude Modulation) to control, its inventor part which the technology realizes but only can output the frequency adjustable square-wave voltage not to be able to adjust the pressure. The pulse width PWM law are precisely in order to overcome, is in the PWM law which the PAM law this shortcoming development comes the simplest one kind. It is each pulse width equal pulse row took the PWM wave, through a change pulse row cycle may the frequency modulation, the change pulse width or the duty factor may adjust the pressure, uses the suitable control method then to cause the voltage and the frequency coordination change. Is opposite in the PAM law, this method merit simplified the electric circuit structure, enhanced the input end power factor, but simultaneously also has in the output voltage besides the fundamental wave, but also contains the big harmonic component.4 Stochastic PWM That time the high efficiency transistor mainly for the bipolarity Daring ton triode, the carrier frequency generally did not surpass 5kHz, the vibration which the electrical machinery winding electromagnetism noise and the overtone created has aroused peoples interest. In order to obtain the improvement, the stochastic PWM method arises at the historic moment. Its principle is the stochastic change turn-on frequency causes the electrical machinery electromagnetism noise to be limited to approximately the belt white noise (in linear frequency coordinate system, various frequencies energy distribution is even), although the noise a decibel number has not always changed, but weakens greatly take the fixed turn-on frequency as the characteristic colored noise intensity. Because of this, even if in IGBT by widespread 5 Space voltage vector PWM controlSpatial voltage vector control PWM (SVPWM) also calls the magnetic flux sine PWM law .It take the three-phase profile whole production effect as the premise, take approaches the electrical machinery air gap the ideal circular rotary field path as the goal, has the actual magnetic flux with the inventor different switch pattern to approach the base director circle magnetic flux, by theirs comparison result decided the inventor the switch, forms the PWM profile. This law embarks from the electric motor angle, regards as the inventor and the electrical machinery a whole, inscribes the polygon to approach the circle the way to carry on the control, causes the electrical machinery to obtain the peak-to-peak value constant circular magnetic field (sine magnetic flux).The concrete method divides into the magnetic flux split-ring type and the magnetic flux closed loop type. The magnetic flux split-ring law synthesizes an equivalent voltage vector with a two non-vanishing vector sum null vector, if the sampling time enough is small, may synthesize the random voltage vector. When this law output ratio-voltage sine-wave modulation enhances 15% close, sum of the harmonic current effective value smallest. The magnetic flux closed loop type introduces the magnetic flux feedback, controls the magnetic flux the size and the change speed .Estimates the magnetic flux after the comparison and assigns the magnetic flux, according to the error decided has the next voltage vector, forms the PWM profile. This method has overcome the magnetic flux split-ring method insufficiency, when has solved the electrical machinery low speed, the stator resistance affects the major problem, reduced the electrical machinery pulsation and the noise. But because has not introduced the torque the adjustment, the system performance has not had the fundamental improvement.直流电机速度控制1 调节系统调节系统是一类通常能提供稳定输出功率的系统。例如，电机速度调节器要能在负载转矩变化时仍能保持电机速度为恒定值。即使负载转矩为零，电机也必须提供足够的转矩来克服轴承的粘滞摩擦影响。其它类型的调节器也提供输出功率，温度调节器必须保持炉内的温度恒定，也就是说，即使炉内的热量散失也必须保持炉温不变。一个电压调节器必须也保持负载电流值变化时输出电压恒定。对于任何一个提供一个输出，例如速度、温度、电压等的系统，在稳态下必定存在一个误差信号。2 电气制动在许多速度控制系统中，例如轧钢机，矿坑卷扬机等这些负载要求频繁地停顿和反向运动的系统。随着减速要求，速度减小的比率取决于存储的能量和所使用的制动系统。一个小型速度控制系统（例如所知的伺服积分器）可以采取机械制动，但这对大型速度控制器并不可行，因为散热很难并且很昂贵。可行的各种电气制动方法有：（1）回馈制动。（2）涡流制动。（3）能耗制动。（4）反向（接）制动。回馈制动虽然并不一定是最经济的方式，但却是做好的方式。负载中存储的能量通过工作电机（暂时以发电机模式运行）被转化成电能并被返回到电源系统中。这样电源就充当了一个收容不想要的能量的角色。假如电源系统具有足够的容量，在短时回馈过程中最终引起的端电压升高会很少。在直流电机速度控制沃特-勒奥那多法中，回馈制动是固有的，但可控硅传动装置必须被排布的可以反馈。如果轴转速快于旋转磁场的速度，感应电机传动装置可以反馈。有晶闸管换流器而来的廉价变频电源的出现在变速装置感应电机应用中引起了巨大的变化。涡流制动可用于任何机器，只要在轴上安装一个铜条或铝盘并在磁场中旋转它即可。在大型系统中，散热问题很重要的，因为如果长时间制动，轴、轴承和电机的温度就会升高。在能耗制动中，存储的能量消耗在回路电阻器上。用在小型直流电机上时，电枢供电被断开，接入一个电阻器（通常是一个继电器、接触器或晶闸管）。保持磁场电压，施加制动降到最低速。感应电机要求稍微复杂一点的排布，定子绕组被从交流电源上断开，接到直流电源上。产生的电能继而消耗在转子回路中。能耗制动应用在许多大型交流升降系统中，制动的职责是反向和延长。任何电机都可以通过突然反接电源以提供反向的旋转方向（反接制动）来停机。在可控情况下，这种制动方法对所有传统装置都是适用的。它主要的缺点就是当制动等于负载存储的能量时，电能被机器消耗了。这在大型装置中就大大增加了运行成本。3 等脉宽PWM法变压变频(Variable Voltage Variable Frequency)装置在早期是采用

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