逻辑控制无环流可逆调速系统设计外文翻译.doc

重庆交通大学二O一二届毕业设计（论文）译文毕业设计（论文）外文翻译题 目 直流电动机无环流 可逆调速系统设计 专 业 电气工程与自动化 班 级 2008级（2）班 学 生 郑凌峰 指导教师 杜军 重庆交通大学 2012 年直流串激电机速度控制的仿真和建模摘要： 直流系列电机是机电一体化中需要高转矩/速度比应用的首选。本文介绍了一个基于微控制器和IGBT的开环直流电动机速度控制系统的设计和实施。这里使用的仿真工具，可以预测的机械和电子模块组成的系统的动态行为。本文提供的仿真结果与实验室测量结果惊人的相似。1.介绍 直流电动机通常被需要高转矩/速度比牵引应用选中。例如轮椅，高尔夫球车，吊机，起重机，驱动器武器等。包括一个典型的应用：人类操作员通过油门踏板或一根杠杆控制直流电动机。按照踏板或杠杆的位置，由电子系统调节电力送入电机的过程，习惯上被称为速度控制。这种控制既可以是在闭环或开环配置中。虽然闭环系统所需的精度高，但是有很多情况下，一个开环系统就足够了。本文关注的是后者的。 一个典型的直流电机调速系统往往有由其内部模拟电路生成和处理内部的信号，而且它的功率驱动阶段有几个并联的MOSFET模块。通过更换或补充模拟与数字电路的功能，或者由单个IGBT替换Mosfet并联模块，改进的控制，从而导致更可靠，成本更低，更简单生产。因此，建议在基于IGB的开环数字速度控制上发展。不过，本文的主要目的是加速提出这种方法的人如何在样机上进行速度控制的。 电机原型通常是在试验和错误的过程中实现的，大部分时间，结果是非常昂贵和费时。这个缺点可以通过适当结合计算机模拟和实验室测试大大缓解。在连接电动马达和其调速系统以前可以用很简单的电机或电子控制模块做模型。 2. 建议设计为直流电动机的速度控制当前数字技术提供了直流电动机生成PWM开关信号的功能和处理保护信号的功能。一个处理器取代模拟模块和与之相关的几个分立器件。控制系统的物理尺寸和生产成本将因此而被降低,与此同时,其可靠性得以提高。图1.踏板信号调理电路.要产生PWM开关信号,Vcond从图1电路输入控制器的第一个A / D转换器输入。 vcond因此离散成256份的水平，他们每个作为一个微控制器E2PROM的地址。相应的存储单元包含脉冲的持续时间。因此，根据Vcond脉冲宽度在256份中不相等。这里正在实施的原型，采用离散的线性变化。然而这种线性特性，可以很容易地改变.其注入到电力驱动器门之前，PWM信号首先通过光电隔离器和经过一个缓冲的阶段（见图2）。在电力电子方面，一个完整的直流到直流H桥转换器有四个IGBT的器件，。然而，这里介绍的，是H桥一个分支的形式（见图 3）。这个分支被当作一个降压转换器。图2.栅极驱动器。 图3.功率输出级.除了防止损失的踏板,其他保护功能在需要电压传感器以及电流和温度传感器的产品中实现。这些设备提供的模拟信号，然后送入微控制器。通过其附加的A / D转换器输入和监控微控制器的程序。3. 使用模拟行为模块的直流串激电机建模3.1汽车方程DC系列电机的机电行为方程描述如下。电气平衡方程2和8 1其中Vs是串联两个串联绕组的电压，EA是感应电动势（EMF），Rt是总的串联电阻，Is是通过绕组电流，LT是总的串联电感。 EA的磁通量和角speed的关系是2和8 2以下列方式，直流电机制定的电磁转矩取决于Is和，其中，Ka是电机常数 3力矩平衡方程2和8： 4其中TL是负载转矩，B是恒定粘性摩擦，J为电机的转子和轴惯性。磁通和绕组中的电流通过本机的磁化曲线表示与2和5有关: 5函数f（IS）一般包括饱和度和滞后效应。3.2DC系列电机的模拟行为建模（1），（2），（3），（4）（5）提供了一个适合的直流串激电机的数学模型，图4为电机反导实施。图4.电机反导实施。图4中1模块是对应EQ的要素的系列分支。请注意，EMF项“EA”模块2注入到这个分支单位增益电压控制电压源。也包括在这个分支是单位增益电流控制电压源，电流传感器。感应电流，需要磁通和电磁转矩TEM两者的计算。磁通量实际上是EA计算的中间变量。结合（5）和（2）。 6 电动机的磁化特性通常是提供了一个EA点 在一个固定值0=180.6 RAD/角速度获得。此值通常对应于电机的额定铭牌速度。让表示Ea0在0这一特点。 （6）根据不同的价值为2： 7 Mn除了到Ea0外。由于粘性摩擦B长期被忽视，8为这个方程收益： 8很明显，从图3中的模块4实现这最后方程。结合（2）（3）到（7）获得的电磁转矩为以下表达式 9 模块3，终于实现了这个最后方程上述电机模型来重现可用1马力系列直流电动机运行。首先，测量这种电机的参数LT，RT和J。然后，磁化特性Ea0 Vs Is集合成80点绘制在图5上，接下来，所有这些数据被应用图4模型。最后，进行各种实验，电机及其反导模型。这些实验设计，以便能够测量细化的参数。此外，ABM电机模型，在实际提供的某些特殊仪器，如测功机中缺乏用于模拟变量和参数的值如下：RT= 55M;= 0.06 kgm2，VS= 12V（A和A之间的张力），查看MATHML源F和寄生电感，忽视LC。绕线电感LT是一个值，只是频率不同。从绕线的阶跃响应实验中得出LT的以下两个值估计：LT=75H的2100赫兹和LT=150H的2500赫兹。中频LT是使用线性插值计算。表1列出了这些值。表1.铭牌和实测值的直流电机符号名牌测量频率0180.6 rad/s额定功率1 hp额定电压12 V额定电流60 A绕线序列线绕电阻Rt55 m绕线电感Lt150 H at 2100 Hz, 75 H at 2500 Hz转子惯量J0.06 kgm23.3 SPICE模型速度控制的建议图1 系统化的建议直流系列电动机速度控制的SPICE模型。它包括四个基本构建模块：踏板信号调理器，微控制器，栅极驱动器和功率输出级。除了微控制器,所有这些模块代表了SPICE模型的制造商详细的使用了半导体器件的细节。我不认为一个微控制器的详细表示是有必要的，此外，它是在这项工作中使用台式电脑是不现实的。这个选择代表PWM功能用来代替通过一个矩形波发生器和宽度是的256脉冲，根据不同步骤的输出信号控制调节器踏板。再被注入到电机模型中,这些PWM信号通过门的驱动和输出功率机建立模型。这里应该提到，除了对踏板信号的保护，其他保护功能的微控制器及其相关电路的损失不模拟。图1 系统化的建议直流系列电动机速度控制的SPICE模型。它包括四个基本构建模块：踏板信号调理器，微控制器，栅极驱动器和功率输出级。除了微控制器,所有这些模块代表了SPICE模型的制造商详细的使用了半导体器件的细节。4.结论本文提出一个复杂的电子，机电原型开发方法。它主要包括与实验室检测相结合的计算机模拟。这种方法得到了进一步的应用在开发一个1马力直流系列电动机的速度控制系统。这里采用的仿真工具是OrCAD及其ABM实用程序“的PSPICE”。虽然PSPICE中允许的电子和电力电子模块的建立，包括制造商提供的详细模块。但是ABM的实用程序，使电机的机电特性的描述得更加准确。从而使连接模拟的电机和电机速度控制也因此成为可能。在这方面模拟和实验室测试两者得到的数据一直令人满意。前人(Chee-Mun, INTUSOFT, HDLA Mentor)的研究结果，已经模拟速度控制，将其耦合到很简单的树枝型电机模型。更现实的电机模型在ABM模型中占有较多的比例。其他开发者可以进一步采用他们，本文提供了必要的数据重构结果如下。此外,第三方甚至可以修改该相对简单的模型，使其相对容易适应特殊需要和其他的发展。模拟结果已经允许了这个实验，甚至在它被调试之前，速度控制已经被调试。例如，帮助建立模拟系统不能启动50以上的占空比整体经验与方法的提出，使得开发时间和成本大幅度降低。模拟与实验工作相结合，甚至缺乏某些专门仪器，如测功机。他们还启用了无法访问变量，如电动势的监测。这是个显着的事实是，在这个项目中没有一个电力电子器件烧毁。最后,正在进行的工作是保持一个完整的定速发展的速度控制,以及对应用这直流电机在不同的维度的ABM模型提供了可能需要修改,以包括额外的功能,如粘滞摩擦、滞后性和频率依赖性的线绕的电感。Simulation and construction of a speedcontrol for a DC series motoAbstractDC series motors are preferred for mechatronic applications requiring high torque/speed ratios. This paper describes the design and implementation of an open loop DC motor speed control that is based on a micro-controller and on IGBTs. Trial and error designs are expensive and time consuming. This problem is solved here by using simulation tools which can predict the dynamic behavior of systems consisting of mechanic and electronic modules. The simulations provided along the paper show a satisfactory agreement with laboratory measurements.1. IntroductionDC series motors usually are selected for traction applications requiring high torque/speed ratios. Examples of these are wheel chairs, golf carts, hoists, cranes, actuator arms, etc. 8. A typical application consists in a human operator driving a DC motor by means of an accelerator pedal or a lever. The electronic system regulating the electric power fed into a motor, in accordance with a pedal or levers position, customarily is referred to as speed control. Such a system can be either in closed or in open loop configuration 8. While closed loop systems are required for high accuracy applications, there are many situations for which an open loop system will suffice. This paper is concerned with the latter ones.A typical DC motor speed control often has its internal signals generated and processed by analog circuitry and has its power driving stage made of several MOSFET modules in parallel 1. This typical control can be improved by replacing or complementing its analog functions with digital ones and, in addition, by substituting each paralleled arrangement of MOSFETs with a single IGBT module 9. The improved control would thus result more reliable, less costly and much simpler to produce. An open loop digital speed control based on IGBTs is thus proposed and developed here. The main purpose of this paper nevertheless is to present the methodology being employed by these authors for developing a working prototype of the proposed speed control.Mechatronic prototypes usually are implemented by a trial and error process which, most of the time, ends up being very expensive and time consuming. It is proposed here that this drawback can be alleviated substantially by properly combining computer simulations and laboratory tests. The conjunct simulation of an electric motor and its speed control has been done before by applying very simple models for the motor and/or for the electronic control modules 1, 8and12.2. Proposed design for a DC motor speed controlCurrent digital technologies provide several clear advantages over the analog ones for the functions of generating the PWM switching signals and of processing the protection signals of the DC motor speed control.Fig. 1.Pedal signal conditioning circuit.To generate the PWM switching signals, Vcond from Fig. 1 circuit is fed into the micro-controllers first A/D converter input. Vcond is thus discretized into 256 levels, each one of them is taken as an address for the micro-controllers E2PROM. The corresponding memory cell contains the intended duration of the pulse. The pulse width is thus varied in 256 steps according to Vcond. A discrete linear variation is adopted here for the prototype being implemented. This linear characteristic, however, could be easily changed if this is deemed convenient.Before their injection into the power driver gates, the PWM signals are first passed through a gate driver stage consisting in an optoelectronic isolator and a buffer. This is shown in Fig. 2. As for the power electronic stage, a full DC to DC H-bridge converter made with four IGBTs and their corresponding parallel diodes is highly recommended 6. For the work reported here, however, only one branch of this bridge is implemented in the form shown in Fig. 3. This branch is made to perform as a step down converter 6.Fig. 2Gate driver.Fig. 3Power output stage.In addition to the protection against loss of pedal, the other protection functions listed above are implemented using voltage sensors as well as current and temperature transducers as needed. The analog signals delivered by these devices are then fed into the micro-controller via its additional A/D converter inputs and their monitoring is made by the micro-controllers program.3. DC series motor modeling using analog behavioral modules3.1. Motor equationsThe equations that describe the electromechanical behavior of a DC series motor are given as follows. The electrical equilibrium equation is 2and8: (1) where Vs is the voltage at the two windings connected in series, Ea is the induced electromotive force (emf), Rt is the total series resistance, Is is the current through the windings and Lt is the total series inductance. The relation of Ea with magnetic flux and angular speed is 2and8 (2) where Ka is a motor constant. The electromagnetic torque developed by the DC motor depends on Is and on in the following manner: (3) The torque balance equation is 2and8: (4) where TL is the load torque, B is the viscous friction constant and J is the motors rotor and shaft inertia. The magnetic flux and the windings current are related through the machines magnetization curve which is denoted as follows 2and5: (5) Function f(Is) in general includes saturation and hysteresis effects.3.2. Analog behavioral modeling of a DC series motor(1), (2), (3), (4)and(5) provide a mathematical model for a DC series motor suitable for the purposes of this paper 2and5. The ABM implementation of this model is shown in Fig. 4.Fig. 4.ABM implementation of the motor.Module 1 of Fig. 4 is a series branch of elements that corresponds to Eq. (1). Note that the emf term “Ea” is injected into this branch from module 2 by a voltage controlled voltage source of unit gain. Included in this branch also is a current controlled voltage source of unit gain which acts as a current sensor. The sensed current is required by modules 3 and 5 in the calculation of both, the magnetic flux and the electromagnetic torque Tem.The magnetic flux actually is an intermediate variable for the calculation of Ea. On combining (5)and(2) (6)The magnetization characteristic of an electric motor usually is provided as a set of points of Ea vs. Is obtained at a fixed value 0=180.6 rad/s of the angular speed. This value usually corresponds to the motors nominal or nameplate speed. Let Ea0 denote this characteristic at 0. According to (6), for a different value of 2: (7)In addition to Ea0, the other input to module 2 is the angular speed calculated by module 4 that corresponds to Eq. (4). On neglecting B, the viscous friction term, this equation yields 8: (8)It is clear from Fig. 4 that module 4 implements this last equation. On combining (2)and(3) into (7) the following expression is obtained for the electromagnetic torque (9)Module 3, finally, implements this last equation.The above-described motor model was used to reproduce the operation of an available 1 hp DC series motor. First, the parameters Lt, Rt and J of this motor were measured. Then, the magnetization characteristic Ea0 vs. Is was obtained as a collection of 80 points which is plotted in Fig. 5. Next, all these data were applied to Fig. 4 model. Finally, various experiments were performed on both, the motor and its ABM model. These experiments were devised so as to permit the refinement of the measured parameters. The ABM motor model, in addition, actually supplied the lack of certain special instruments, such as a dynamometer. The values of the variables and parameters used for the simulations are as follows: Rt=55 m, J=0.06 kgm2, Vs=12 V (tension between A and A), F and the parasitic inductance Lc was neglected. The wound inductance Lt is a value that varies with frequency 10. From the wounds step response the following two values of Lt were estimated experimentally: Lt=75 H at 2100 Hz and Lt=150 H at 2500 Hz. At intermediate frequencies Lt is calculated using linear interpolation. These values are listed in Table 1.Table 1. Name plate and measured values of the DC motorSymbolName plateMeasuredNominal frequency0180.6 rad/sRated power1 hpRated voltage12 VRated current60 AWoundSeriesWound resistanceRt55 mWound inductanceLt150 H at 2100 Hz, 75 H at 2500 HzRotor inertiaJ0.06 kgm23.3. SPICE model of the proposed speed controlFig. 1 schematizes the SPICE model of the proposed DC series motor speed control. It consists of four basic building blocks: pedal signal conditioner, micro-controller, gate driver and power output stage. Except for the micro-controller, all these blocks are represented in great detail using manufacturer provided SPICE models for the semiconductor devices being used.A detailed representation of the micro-controller is not deemed necessary and, besides, it is unrealistic for the desktop computer being used in this work. It was opted instead for representing the PWM function only by means of a rectangular wave generator with its pulse width being varied in 256 steps according to the output of the pedal signal conditioner. Before being injected into the motor model, these PWM signals are passed through the gate driver and the power output models. It should be mentioned here that, apart from the protection against loss of pedal signals, the other protection functions of the micro-controller and their associated circuitry were not included in the simulation.The detailed diagram for the pedal signal conditioner is the one provided in Fig. 1, while the diagrams for the gate driver and for the power output stage are provided in Fig. 2andFig. 3 An advantage of using SPICE for the modeling of these blocks is the access to a vast library of models for commercially available devices 4. Only the model for the IGBT module was not in this library, but it could be easily downloaded from the manufacturers web information site. Before its physical implementation, the speed control SPICE model was tested along with the ABM motor model. This permitted the debugging and fine-tuning of the preliminary design even before its implementation.4. ConclusionsA methodology for developing complex electronicelectromechanical prototypes has been presented in this paper. It consists essentially in combining computer simulations with laboratory tests. This methodology has been further applied in the development of a speed control for an 1 hp DC series motor. The simulation tools adopted here are PSPICE from OrCAD and its ABM utilities.While PSPICE has permitted a detailed representation of the electronics and power electronics modules which include manufacturers supplied modules, the ABM utilities have enabled the accurate description of the motors electromechanical features. The conjunct simulation of the motor and its speed control has thus been possible. The agreement attained here betw