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1、 第1章 引 言41.1设计目的41.2设计要求5第2章 系统总体设计62.1总体思路62.2总体设计6第3章 双闭环调速系统设计83.1系统的总体框图设计83.2 电流调节器的设计83.3转速调节器的设计10第4章 系统仿真12第5章 总结14参考文献15 基于工程设计法的双闭环直流调速系统设计 【摘要】 本文按工程方法设计了一个直流电机的转速和电流双闭环调速系统。该系统设计了电流检测环节，电流调节器以及转速检测环节、转速调节器，构成了电流环和转速环，前者通过电流元件的反馈作用稳定电流，后者通过转速检测元件的反馈作用保持转速稳定，最终消除转速偏差，从而使系统达到调节电流和转速的目的，并通过S
2、imulink进行系统仿真，分析双闭环直流调速系统的特性。【关键词】 双闭环 电流调节器 转速调节器 SimulinkEngineering design method based on double closed-loop DC motor control system design【Abstract】 This project designed by a DC moter speed and current dual-loop speed control system.The system sets up the current detecting aspect,the current r
3、egulator ACR and the speed detecting link,speed regulator ASR,composes the current central and the speed central,the former through the feedback of the current components to level off the current,the latter through the feedback of speed detecting device to maintain the speed stably and finally elimi
4、nates the deviation of speed bias,thus allowing the system to the purpose of regulating the current and speed.Simulink for system through system simulation,finally display control system model and the results of anti-truth. 【Keywords】 Double-loop the speed regulator the current regulator Simulink第1章
5、 引 言 20世纪60年代以前，在电气传动领域中，我们曾广泛使用的是由机组供电的直流调速系统，但该系统需要旋转变流机组，至少包含两台与调速电动机容量相当的旋转电机，还要一台励磁发电机，因此，该系统所需设备多，体积大，费用高，效率低。1957年，晶闸管问世，晶闸管变流装置开始取代旋转变流机组，产生了晶闸管电动机调速系统，大大提高了系统的动态性能。但晶闸管整流装置也有其缺点，由于晶闸管的单向导电性，不允许电流反向，给系统的可逆运行造成了困难。如今，可逆脉冲宽度调制器成为直流调速系统的主要方法。在工程设计与理论学习中，我们会接触到大量关于调速控制系统的分析、综合与设计问题。双闭环调速系统是一种当前应
6、用广泛、经济、适用的电力传动系统。他具有动态响应快，抗干扰能力强等优点。我们知道反馈闭环控制系统具有良好的抗扰性能，它对于被反馈环前向通道上的一切扰动作用都能有效的加以抑制。采用转速负反馈和PI调节器的单闭环调速系统可以再保证系统稳定的条件下实现转速无静差。但如果对系统的动态性能要求较高，例如要求起制动、突加负载动态速降等，就难以满足要求。这主要是因为在单闭环系统中不能完全按照需要来控制动态过程的电流或转矩。在单闭环系统中，只有电流截止至负反馈环节是专门用来控制电流的，但它只是在超过临街电流值以后，强烈的负反馈作用限制电流的冲击，并不能很理想的控制电流的动态波形。在实际工作中，我们希望用最大的
7、加速度启动，到达稳定转速后，又让电流降下来，使转矩马上与负载相平衡，从而转入稳态运行。因此，我们可以采用双闭环直流调速达到这种效果。1.1设计目的为了进一步提高对所学知识的运用能力，以及对运动控制系统一书的深入了解，会运用所学知识来设计一般的控制系统。通过设计，一方面掌握设计方法、技巧，另一方面加强理论结合实际及指导解决实际问题的途径，以期达到理论与实际的统一，从而提高同学们对科学实验的兴趣和能力。既培养学生基于所学知识分析和综合典型系统的能力，又使学生理解典型系统的工程背景、在掌握基础理论和方法三、提高解决实际自动控制系统问题的能力。1.2设计要求按工程设计方法设计一个直流电机的转速和电流双
8、闭环调速系统。通过控制电枢电压改变电动机的转速，电枢电压由三相桥式整流电路提供。系统参数：电动机的额定数据为：，电动势系数，主回路总电阻，允许的电流过载倍数，触发整流环节的放大倍数。电磁时间常数，机电时间常数，电流反馈滤波时间常数，转速反馈滤波时间常数。额定转速时给定电压，调节器ASR,ACR饱和输出电压，。设计指标：稳态无静差，电流超调量，空载起动到额定转速时的转速超调量。第2章 系统总体设计2.1总体思路采用PI调节的单个转速闭环直流调速系统可以在保证系统稳定的前提下实现转速无静差，但是，如果对系统的动态性能要求较高，例如对于经常正、反转运行的龙门刨床、可逆轧钢机，要求快速起制动，因为尽量
9、缩短其、制动时间是提高生产率的重要因素，为此，在电机最大允许电流和转矩受限制的条件下，应该充分利用电机的过载能力，最好在过渡过程中始终保持电流为允许的最大值，使电力拖动系统以最大加速度起动，到达稳态转速时，立即让电流降下来，使转矩马上与负载相平衡，从而转入稳态运行。因此，我们可以采用转速、电流双闭环调速来实现。为了实现转速和电流两种负反馈分别起作用，可以在系统中设置两个调节器，分别调节转速和电流，即分别引入转速负反馈和电流负反馈，二者之间实现串级连接，形成转速、电流双闭环调速控制。2.2总体设计方案一：单闭环直流调速系统单闭环直流调速系统是由一个转速负反馈构成的闭环控制系统。在电动机轴上装一台
10、测速发电机，引出与转速成正比的电压与给定电压比较后，得到偏差电压，经放大器，产生触发装置的控制电压，用以控制电动机得转速。该系统可以保证系统稳定的前提下实现转速无静差，但是，如果对系统的动态性能要求较高，就难以满足要求。原理框图如图2-1 图2-1 方案二：双闭环直流调速系统 该方案主要由给定环节、ASR、ACR、触发器和整流装置环节、速度检测环节以及电流检测环节组成。为了使转速负反馈和电流负反馈分别起作用，系统设置了电流调节器和转速调节器，电流调节器和电流检测反馈回路构成了电流环，转速调节器和转速检测反馈回路构成转速环。因转速环包围电流环，故电流环称为内环，转速环为外环。在电路中，ASR和A
11、CR串联，把ASR的输出当作ACR的输入，再由ACR的输出去控制整流器的触发器。为了获得良好的静、动态性能。转速和电流两个调节器都采用具有输入输出限幅功能的PI调节器，且转速和电流都采用负反馈闭环。双闭环调速系统弥补了单闭环调速系统的缺点，能够满足动态性能要求。图2-2综上所述，我们选用双闭环直流调速系统第3章 双闭环调速系统设计3.1系统的总体框图设计 根据设计的要求，本文所设计的双闭环直流调速系统主要包含转速给定电路、转速检测电路、电流检测电路、整流电路等几部分，系统的总体框图如下： 图3-13.2 电流调节器的设计1.确定时间常数（1）整流装置滞后时间常数，三相桥式整流电路的失控时间=0
12、.0017s。（2）电流滤波时间常数，三相桥式电路每个波头的时间是3.3ms，为了基本滤平波头，应有=3.33ms，因此取（3）电流环小时间常数之和，按小时间常数近视处理，取。2.确定将电流环设计成为何种典型结构根据设计要求：，而且，因此，设计成典型系统3.电流调节器的结构选择电流调节器选用PI调节器，其传递函数可设为式中电流调节器的比例系数 电流调节器的超前时间常数4.选择电流调节器参数（1）电流调节器超前时间常数:。（2）电流开环增益：因，故取，因此=135.1，于是电流调节器的比例系数（3）电流反馈系数：5 校验近似条件电流环截止频率（1）校验晶闸管装置传递函数的近似条件是否满足。因为，
13、所以满足近似条件。（2）校验忽略反电动势对电流环影响的近似条件是否满足。现在，满足近似条件。（3）校验小时间常数的近似处理是否满足条件。现在，满足近似条件。电流环结构框图： 图3-23.3转速调节器的设计1.确定时间常数（1）电流环等效时间常数为；（2）转速滤波时间常数。根据所用测速发电机纹波情况，取；（3）转速环小时间常数。按小时间常数近似处理，取。2. 确定将转速环设计成何种典型系统由于设计要求转速无静差，转速调节器必须含有积分环节；有根据动态设计要求，应按典型型系统设计转速环。3.转速调节器的结构选择转速调节器选用PI型，其传递函数为：。转速调节器的比例系数转速调节器的超前时间常数4.选
14、择转速调节器参数（1）按跟随和抗绕性能都较好的原则取h=5，则ASR超前时间常数：；（2）转速开环增益：；（3）ASR的比例系数为：（4）转速反馈系数：5 校验近似条件转速环截止频率（1）电流环传递函数简化条件（2）校验小时间常数的近似处理是否满足条件。现在，满足近似条件。（3）校核转速超调量。当h=5时，不能满足设计要求，实际上这是按线性系统计算的，而突加阶跃给定时，饱和，不符合线性系统的前提，应该按退饱和的情况重新计算超调量。当h=5时，；而，因此，能满足设计要求。转速环框图如下： 图3-3第4章 系统仿真由于本文只进行了理论性设计，故在系统安装与调试阶段对控制部分进行MATLAB仿真，以
15、分析直流电机的启动特性，采用MATLAB的simulink工具箱对系统在阶跃输入下的动态响应进行仿真，系统仿真结构如图所示： 图4-1在额定转速和空载下，对系统进行仿真得到电动机电枢电流和转速的仿真输出波形。转速波形：电流波形：控制电压Uc的波形：以上表明，利用matlab仿真平台对直流调速系统理论设计与调试，使得系统的性能分析过程简单。通过对系统进行仿真，可以准确地了解到理论设计与实际系统之间的偏差，逐步改进系统结构及参数，得到最优调节器参数，使得系统的调试得到简化，缩短产品的开发周期。第5章 总结待添加的隐藏文字内容1经过这次的课程设计，不仅使在书上学到的知识得到了巩固，而且还在设计中拓展
16、了其它没学过的知识，比如我学会了如何用公式编辑器，如何用VISIO进行画图，如何用MATLAB进行仿真，这些软件的学会当然少不了老师和同学帮组，也提高了我的自学能力。这次课程设计，通过查找资料，了解情况，让我明白了课本上的知识该用到什么地方，也了解到理论学习与工程设计的区别，加深了我对所学知识的理解。参考文献1 陈桂明，应用MATLAB建模与仿真，科学出版社，20022 姬富德，基于matlab的矢量控制系统仿真，矿山机械出版社，20013 陈伯时，电力拖动自动控制系统运动控制系统，第三版，机械工业出版社，20034李发海，王岩，电机拖动基础，第三版，清华大学出版社，2005 Employme
17、nt tribunals sort out disagreements between employers and employees.You may need to make a claim to an employment tribunal if: you dont agree with the disciplinary action your employer has taken against you your employer dismisses you and you think that you have been dismissed unfairly.For more info
18、rmation about dismissal and unfair dismissal, seeDismissal.You can make a claim to an employment tribunal, even if you haventappealedagainst the disciplinary action your employer has taken against you. However, if you win your case, the tribunal may reduce any compensation awarded to you as a result
19、 of your failure to appeal.Remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are complaining about happened. If your application is received after this time limit, the tribunal will not usually accept i.If you are wo
20、rried about how the time limits apply to you, take advice from one of the organisations listed underFurther help.Employment tribunals are less formal than some other courts, but it is still a legal process and you will need to give evidence under an oath or affirmation.Most people find making a clai
21、m to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you should get help straight away from one of the organisations listed underFurther help.If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement whe
22、re you pay their fee out of your compensation if you win the case. This is known as adamages-based agreement. In England and Wales, your solicitor cant charge you more than 35% of your compensation if you win the case.If you are thinking about signing up for a damages-based agreement, you should mak
23、e sure youre clear about the terms of the agreement. It might be best to get advice from an experienced adviser, for example, at a Citizens Advice Bureau. To find your nearest CAB, including those that give advice by e-mail, click onnearest CAB.For more information about making a claim to an employm
24、ent tribunal, seeEmployment tribunals.The (lack of) air up there Watch mCayman Islands-based Webb, the head of Fifas anti-racism taskforce, is in London for the Football Associations 150th anniversary celebrations and will attend Citys Premier League match at Chelsea on Sunday.I am going to be at th
25、e match tomorrow and I have asked to meet Yaya Toure, he told BBC Sport.For me its about how he felt and I would like to speak to him first to find out what his experience was.Uefa hasopened disciplinary proceedings against CSKAfor the racist behaviour of their fans duringCitys 2-1 win.Michel Platin
26、i, president of European footballs governing body, has also ordered an immediate investigation into the referees actions.CSKA said they were surprised and disappointed by Toures complaint. In a statement the Russian side added: We found no racist insults from fans of CSKA.Age has reached the end of
27、the beginning of a word. May be guilty in his seems to passing a lot of different life became the appearance of the same day; May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly. Always feel oneself should go t
28、o do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it.一字开头的年龄已经到了尾声。或许是愧疚于自己似乎把转瞬即逝的很多个不同的日子过成了同一天的样子；或许是追溯过去，对自己那些近乎偏执的怪异信念的醒悟，这些天以来，思绪一直很凌乱，在脑海中不断纠缠。总觉得自己自己似乎应该去做点什么，或者写点什么。二十年的人生轨迹深深浅浅，突然就感觉到有些事情，非做不可了。The end of our life, and can meet
29、many things really do?而穷尽我们的一生，又能遇到多少事情是真正地非做不可？During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of the age, will be more and more found that those things are optional; Junior high school, thought to have a crush on just means that the real growth
30、, but over the past three years later, his writing of alumni in peace, suddenly found that isnt really grow up, it seems is not so important; Then in high school, think dont want to give vent to out your inner voice can be in the high school children of the feelings in a period, but was eventually i
31、nfarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already cant remember his appearance.童年时，觉得压岁钱和新衣服是过年必备，但是随着年龄的推进，会越来越发现，那些东西根本就可有可无；初中时，以为要有一场暗恋才意味着真正的成长，但三年过去后，自己心平气和的写同学录的时候，突
32、然就发现是不是真正的成长了，好像并没有那么重要了；然后到了高中，觉得非要吐露出自己的心声才能为高中生涯里的懵懂情愫划上一个句点，但毕业晚会的时候最终还是被梗塞在了咽喉，后来再次站在他曾经挥汗如雨的球场，看着他投过篮球的球框时，突然间发现自己已经想不起他的容颜。Originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to do, and time.原来，这个世界上，对某个事件能产生化学反应的，除了非做不可的坚决，还有，时间。A persons time
33、, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there are a lot of love, there are a lot of miss, like shadow real
34、ly have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a self-righteous spiritual.一个人的时候，自己的想法总是特别地清晰。想要的，不想要的，界限明确，好像没有什么可以撼动自己。也曾经好像已经下定了决心去做某件事，但更多的时候是最后又打起了退堂鼓。嫌恶过自己的怯懦，最终却发现有很多缘分，有很多错过，好像冥冥之中真的已经注定。那些曾经所谓的非做不可，只是青葱年华里自己给自己注射的一支强心剂，或者说，是自以为是的精神寄托罢了。At th
35、e moment, the sky is dark, the air is fresh factor after just rained. Suddenly thought of blue plaid shirt; Those were broken into various shapes of stationery; From the corner at the beginning of deep friendship; Have declared the end of the encounter that havent start planning. Those years, those
36、days of do, finally, like youth, will end in our life.此刻，天空是阴暗的，空气里有着刚下过雨之后的清新因子。突然想到那件蓝格子衬衫；那些被折成各种各样形状的信纸；那段从街角深巷伊始的友谊；还有那场还没有开始就宣告了终结的邂逅计划那些年那些天的非做不可，终于和青春一样，都将在我们的人生中谢幕。Baumgartner the disappointing news: Mission aborted. r plays an important role in this mission. Starting at the ground, conditi
37、ons have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. It will climb higher than the tip of Mount Everes
38、t (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.The supersonic descent could happen as early as Sund
39、a.The weatheThe balloon will slowly drift to the edge of space at 120,000 feet ( Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform.Below, the Earth becomes the concrete bottom of a swimming pool that he wants to land on, but not too hard. Still, hell
40、be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jumpWhen he jumps, he is expected to reach the speed of sound - 690 mph (1,110 kph) - in less than 40 seconds. Like hittin
41、g the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him completely.If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him down. His team hopes its not needed. In
42、stead, he plans to deploy his 270-square-foot (25-square-meter) main chute at an altitude of around 5,000 feet (1,524 meters).In order to deploy this chute successfully, he will have to slow to 172 mph (277 kph). He will have a reserve parachute that will open automatically if he loses consciousness at mach speeds.Even if everything goes as planned, it wont. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters).cause there