直流電動機雙閉環(huán)調(diào)速系統(tǒng)的研究外文翻譯

1、word格式整理版中國地質(zhì)大學(xué)長城學(xué)院本科畢業(yè)設(shè)計外文資料翻譯系 別信息工程系學(xué)生姓名專業(yè)電氣工程及其自動化學(xué)號 043111312015年3月1日外文資料翻譯譯文直流電動機雙閉環(huán)調(diào)速系統(tǒng)的研究1 .概述直流電動機具有良好的起、制動性能，宜于在大范圍內(nèi)實現(xiàn)平滑調(diào)速，并且直流調(diào)速 系統(tǒng)在理論和實踐上都比較成熟，是研究其它調(diào)速系統(tǒng)的基礎(chǔ)。而用MATLA瞅件對直流調(diào)速系統(tǒng)進行虛擬環(huán)境下的仿真研究，不僅使用方便，也大大降低了研究成本。本文敘述了直流電動機的基本原理和調(diào)速原理，介紹了直流電動機開環(huán)和雙閉環(huán)調(diào)速 系統(tǒng)的組成及靜、動態(tài)特性，并且根據(jù)直流電動機的基本方程建設(shè)立了調(diào)速系統(tǒng)的數(shù)學(xué)模 型，給出了動態(tài)

2、結(jié)構(gòu)框圖，用工程設(shè)計方法設(shè)計了直流電動機雙閉環(huán)調(diào)速系統(tǒng)。最后，用 MATLA防真軟件搭建了仿真模型，對調(diào)速系統(tǒng)進行了仿真研究。通過對直流電動機雙閉環(huán)調(diào)速系統(tǒng)動態(tài)特性的研究與仿真，可以清楚地看到，直流電 動機雙閉環(huán)調(diào)速系統(tǒng)具有較好的動態(tài)性能， 可以在給定調(diào)速范圍內(nèi)，實現(xiàn)無靜差平滑調(diào)速， 這為直流電動機調(diào)速系統(tǒng)的硬件實驗提供了理論依據(jù)。2 .雙閉環(huán)直流調(diào)節(jié)系統(tǒng)的研究背景直流調(diào)速是現(xiàn)代電力拖動自動控制系統(tǒng)中發(fā)展較早的技術(shù)。在20世紀(jì)60年代，隨著品閘管的出現(xiàn)，現(xiàn)代電力電子和控制理論、計算機的結(jié)合促進了電力傳動控制技術(shù)研究和 應(yīng)用的繁榮。晶閘管-直流電動機調(diào)速系統(tǒng)為現(xiàn)代工業(yè)提供了高效、高性能的動力。盡

3、管 目前交流調(diào)速的迅速發(fā)展，交流調(diào)速技術(shù)越趨成熟，以及交流電動機的經(jīng)濟性和易維護性， 使交流調(diào)速廣泛受到用戶的歡迎。但是直流電動機調(diào)速系統(tǒng)以其優(yōu)良的調(diào)速性能仍有廣闊 的市場，并且建立在反饋控制理論基礎(chǔ)上的直流調(diào)速原理也是交流調(diào)速控制的基礎(chǔ)?，F(xiàn)在 的直流和交流調(diào)速裝置都是數(shù)字化的，使用的芯片和軟件各有特點，但基本控制原理有其 共性。對于那些在實際調(diào)試過程中存在很大風(fēng)險或?qū)嶒炠M用昂貴的系統(tǒng)，一般不允許對設(shè)計 好的系統(tǒng)直接進行實驗。然而沒有經(jīng)過實驗研究是不能將設(shè)計好的系統(tǒng)直接放到生產(chǎn)實際 中去的。因此就必須對其進行模擬實驗研究。當(dāng)然有些情況下可以構(gòu)造一套物理裝置進行 實驗，但這種方法十分費時而且費用

4、又高，而且在有的情況下物理模擬幾乎是不可能的。 近年來隨著計算機的迅速發(fā)展，采用計算機對控制系統(tǒng)進行數(shù)學(xué)仿真的方法已被人們采 納。但是長期以來，仿真領(lǐng)域的研究重點是仿真模型的建立這一環(huán)節(jié)上，即在系統(tǒng)模型建 立以后要設(shè)計一種算法。以使系統(tǒng)模型等為計算機所接受，然后再編制成計算機程序，并 在計算機上運行。因此產(chǎn)生了各種仿真算法和仿真軟件。由于對模型建立和仿真實驗研究較少，因此建模通常需要很長時間，同時仿真結(jié)果的 分析也必須依賴有關(guān)專家，而對決策者缺乏直接的指導(dǎo)，這樣就大大阻礙了仿真技術(shù)的推廣應(yīng)用。MATLABI供動態(tài)系統(tǒng)仿真工具 Simulink ,則是眾多仿真軟件中最強大、最優(yōu)秀、最 容易使用的

5、一種。它有效的解決了以上仿真技術(shù)中的問題。在 Simulink中，對系統(tǒng)進行 建模將變的非常簡單，而且仿真過程是交互的，因此可以很隨意的改變仿真參數(shù)，并且立 即可以得到修改后的結(jié)果。另外，使用MATLAB的各種分析工具，還可以對仿真結(jié)果進行分析和可視化。Simulink可以超越理想的線性模型去探索更為現(xiàn)實的非線性問題的模型，如現(xiàn)實世界中的摩擦、空氣阻力、齒輪嚙合等自然現(xiàn)象；它可以仿真到宏觀的星體，至微觀的分子原 子，它可以建模和仿真的對象的類型廣泛，可以是機械的、電子的等現(xiàn)實存在的實體，也 可以是理想的系統(tǒng)，可仿真動態(tài)系統(tǒng)的復(fù)雜性可大可小，可以是連續(xù)的、離散的或混合型 的。Simulink會使

6、你的計算機成為一個實驗室，用它可對各種現(xiàn)實中存在的、不存在的、 甚至是相反的系統(tǒng)進行建模與仿真。自70年代以來，國內(nèi)外在電氣傳動領(lǐng)域內(nèi)，大量地采用了 “晶閘管直流電動機調(diào)速” 技術(shù)（簡稱YM調(diào)速系統(tǒng)）。盡管當(dāng)今功率半導(dǎo)體變流技術(shù)已有了突飛猛進的發(fā)展，但在 工業(yè)生產(chǎn)中V M系統(tǒng)的應(yīng)用量還是占有相當(dāng)?shù)谋戎?。在工程設(shè)計與理論學(xué)習(xí)過程中，會 接觸到大量關(guān)于調(diào)速控制系統(tǒng)的分析、綜合與設(shè)計問題。傳統(tǒng)的研究方法主要有解析法， 實驗法與仿真實驗，其中前兩種方法在具有各自優(yōu)點的同時也存在著不同的局限性。隨著 生產(chǎn)技術(shù)的發(fā)展，對電氣傳動在啟制動、正反轉(zhuǎn)以及調(diào)速精度、調(diào)速范圍、靜態(tài)特性、動 態(tài)響應(yīng)等方面提出了更高

7、要求，這就要求大量使用調(diào)速系統(tǒng)。由于直流電機的調(diào)速性能和 轉(zhuǎn)矩控制性能好，從20世紀(jì)30年代起，就開始使用直流調(diào)速系統(tǒng)。它的發(fā)展過程是這樣 的：由最早的旋轉(zhuǎn)變流機組控制發(fā)展為放大機、磁放大器控制；再進一步，用靜止的晶閘 管變流裝置和模擬控制器實現(xiàn)直流調(diào)速；再后來，用可控整流和大功率晶體管組成的PWM控制電路實現(xiàn)數(shù)字化的直流調(diào)速，使系統(tǒng)快速性、可控性、經(jīng)濟性不斷提高。調(diào)速性能的 不斷提高，使直流調(diào)速系統(tǒng)的應(yīng)用非常廣泛。在工業(yè)生產(chǎn)中，需要高性能速度控制的電力拖動場合，直流調(diào)速系統(tǒng)，特別是雙閉環(huán)直 流調(diào)速系統(tǒng)發(fā)揮著極為重要的作用。轉(zhuǎn)速、電流雙閉環(huán)調(diào)速系統(tǒng)是20世紀(jì)60年代在國外出現(xiàn)的一種新型調(diào)速系統(tǒng)

8、。70年代以來，在我國的冶金、機械、制造以及印染工業(yè)等領(lǐng)域 得到日益廣泛的應(yīng)用。雙閉環(huán)調(diào)速系統(tǒng)是由單閉環(huán)自動調(diào)速系統(tǒng)發(fā)展而來的。它通過轉(zhuǎn)速 和電流兩個調(diào)節(jié)器分別引入轉(zhuǎn)速負反饋和電流負反饋，并構(gòu)成雙閉環(huán)系統(tǒng)。從而有效的改 善電機性能。 本設(shè)計主要采用三相全控橋式整流電路對直流電機供電，并通過工程設(shè)計 法對轉(zhuǎn)速調(diào)節(jié)器和電流調(diào)節(jié)器相關(guān)參數(shù)進行計算以達到對轉(zhuǎn)速電流雙閉環(huán)支流調(diào)速系統(tǒng) 的整體實現(xiàn)。3系統(tǒng)工作原理該系統(tǒng)主要由主開關(guān)，電機勵磁電路，品閘管調(diào)速控制電路（包括轉(zhuǎn)速表電路），整 流濾波電路，平波電抗器放電電路，能耗制動電路，整個系統(tǒng)采用閉環(huán)PI調(diào)節(jié)器控制的實現(xiàn)。當(dāng)主開關(guān)閉合，這單相交流獲得小的脈沖

9、持續(xù)電流通過晶閘管調(diào)速控制電路的控制， 和整流橋，為電機的濾波及平波電抗器，并在同一時間，通過整流勵磁電路，交流使電機 獲得激勵去開始工作。在調(diào)節(jié)觸發(fā)電路的速度設(shè)置電位器RP1由PIC16F877減少時，AN1輸入電壓下降使輸出控制的角度，和晶閘管隨流角，和主電路提高輸出電壓，和電機轉(zhuǎn)速 增加，增大和測速電路的輸出電壓，和電機穩(wěn)定運行在設(shè)定的速度范圍通過PI調(diào)節(jié)器的功能。4 .在系統(tǒng)各部分電路的設(shè)計4.1 主電路的設(shè)計對電路中的各種成分的參數(shù)設(shè)置，如圖 3所示。按下啟動按鈕開關(guān) SW使接觸器KM 和KM回路，常開觸點閉合，具常閉觸點打開，并啟動按鈕自鎖，主電路連接，與品閘管 調(diào)速電路通過改變雙

10、向晶閘管的控制角控制的交流輸出，并通過橋梁得到直流整流和濾 波，同時，電機通過整流勵磁電路獲得激勵開始工作。限制直流脈動，在電路中連接平波 電抗器，和電阻R3提供放電回路平波電抗器在主電路突然斷了。加快制動，能耗制動是 采用的設(shè)備，和制動部分由電阻 R4和主電路接觸器的常閉觸點。電動機的勵磁是由單一的整流電路供電，并防止無法控制的高速事故通過電機的勵磁 損耗引起的，在激勵電路中，用聯(lián)電流繼電器 KA和動作電流可以通過調(diào)節(jié)電位器 RP 4.2晶閘管觸發(fā)電路的設(shè)計在主電路中的A點和B點的電壓變?yōu)?0V通過變壓器，然后整流，約100小時半的信 號發(fā)生在這兩個點，并與NPNE極管通過信號分壓R6和R7

11、的放大，在三極管集電極產(chǎn)生 過零脈沖，并捕獲零通道脈沖上升沿的CCP1模塊和注意發(fā)生第一時間，趕過零脈沖下降的邊緣，和兩者之間的時間差為零的脈沖寬度，和值的一半是中點的脈沖，通過捕捉模式， 我們可以準(zhǔn)確地獲得實際的過零點的交流，并在同時，我們可以利用ADC的模擬/數(shù)字轉(zhuǎn)換模塊將PIC16F877引腳的模擬電壓RA1 / AN1所設(shè)定的晶閘管控制的角度值（設(shè)定電機 的轉(zhuǎn)速值），改變設(shè)定值電位器 RP1和相應(yīng)地改變設(shè)置的晶閘管控制角的值，并輸出值轉(zhuǎn) 速表電路由銷RA1/AN1 PIC16F877的輸入，和值作為速度反饋值通過 A/D轉(zhuǎn)換。在單片機 系統(tǒng)的振蕩頻率為4MHz并根據(jù)特征PIC16F87

12、7訂貨周期，品閘管控制角的分辨率是四分 之一單片機振蕩的倒數(shù)1仙的頻率，即，在電力10ms的半波時間，控制角可以達到10000 的步驟，完全實現(xiàn)電動機的無級平滑控制。4.3 測速電路設(shè)計轉(zhuǎn)速表電路由光學(xué)編碼盤吸積與電機轉(zhuǎn)子和電脈沖放大整形電路。電脈沖頻率固定的 比例與電動機的轉(zhuǎn)速，和通過放大整形，由光學(xué)碼盤輸出電脈沖從引腳RC0 /T1CK1輸入PIC16F877作為標(biāo)準(zhǔn)的TTL電平，由計數(shù)TMR價數(shù)器計算轉(zhuǎn)速，并比較與預(yù)設(shè)轉(zhuǎn)速和轉(zhuǎn)速 得到差值，與PIC16F877單片機實現(xiàn)PI操作這種差異的價值得到增加的控制，并將品閘 管的控制角來改變有效CCP2t機的兩個端口的電壓，從而控制轉(zhuǎn)速。5 .結(jié)

13、論本次研究的課題一直流電機雙閉環(huán)調(diào)速系統(tǒng)的動態(tài)特性研究與仿真，是基于工程設(shè)計 的方法，即用工程設(shè)計方法設(shè)計直流電動機轉(zhuǎn)速、電流雙閉環(huán)調(diào)速系統(tǒng)。根據(jù)直流電機的 基本方程建立調(diào)速系統(tǒng)的數(shù)學(xué)模型，給出動態(tài)結(jié)構(gòu)框圖，并用MATLAB建設(shè)仿真模型，進行相關(guān)參數(shù)的調(diào)試與仿真，對仿真結(jié)果進行分析、研究，驗證控制方案的合理性。此次研究雖最終得到了滿意的結(jié)果，但在進行系統(tǒng)仿真時也遇到了不少問題，主要原 因在于系統(tǒng)建模與參數(shù)調(diào)試時沒有技巧?，F(xiàn)在我把本次仿真中獲得的一些技巧作個簡單的 總結(jié)：(1)系統(tǒng)建模時，要分為主電路和控制電路分別進行。(2)在參數(shù)設(shè)置時，晶閘管整流橋和 6脈沖觸發(fā)器按仿真需要選擇合適的參數(shù)，平

14、波 電抗器和直流電動機中應(yīng)代入實際計算值，沒有相關(guān)要求的參數(shù)取默認值即可。(3)仿真時間的選擇按實際情況而定，以出現(xiàn)完整的波形為前提。(4)調(diào)節(jié)器和反饋參數(shù)按計算結(jié)果代入。(5)若雙閉環(huán)仿真中出現(xiàn)問題，可以在開環(huán)的基礎(chǔ)上，一步一步增加反饋環(huán)節(jié)，調(diào)節(jié) 環(huán)節(jié)和限幅環(huán)節(jié)，不斷調(diào)試，最終完成雙閉環(huán)的仿真。(6)參數(shù)調(diào)試時，我們還應(yīng)耐心觀察，認真分析，及時比較，不斷優(yōu)化系統(tǒng)。此次研究結(jié)果表明，直流電動機雙閉環(huán)調(diào)速系統(tǒng)可以在給定調(diào)速范圍內(nèi)實現(xiàn)無靜差平 滑調(diào)速。由于其超調(diào)量較小，系統(tǒng)具有較好的穩(wěn)定性、較高的穩(wěn)態(tài)精度以及優(yōu)良的動態(tài)性 能，這不僅為直流調(diào)速實驗提供了理論依據(jù)，也為其它調(diào)速系統(tǒng)的研究打牢了理論基礎(chǔ)

15、。 但是其快速性要稍微差一點，這有待于以后繼續(xù)研究。學(xué)習(xí)參考Double closed loop dc motor speed control systemresearch1. An overview of theDc motor has good starting and brake performance, adaptable to achieve smooth speed regulation in large scale, and dc speed regulating system in theory and practice are more mature, is the basi

16、s of the study other speed regulation system. And MATLAB software to dc speed regulating system in a virtual environment of simulation research, not only easy to use, also greatly reduces the cost of research.Is described in this paper, the basic principle of the dc motor and speed control principle

17、, this paper introduces the dc motor open loop and double closed-loop speed control system composition and the static and dynamic characteristics, and according to the basic equation of the construction of dc motor made the mathematical model of speed control system, dynamic structure diagram are gi

18、ven, with engineering design method of dc motor double closed loop speed control system is designed. Finally, the MATLA&imulation software to build the simulation model of speed control system for the study of the simulation.Through the dynamic characteristics of a dc motor double closed loop sp

19、eed regulation system in the research and simulation, can see clearly that dc motor double closed loop speed regulation system has good dynamic performance, can be in the given speed range, realize the astatic smooth speed regulation,For the dc motor speed control system hardware experiments provide

20、 a theoretical basis.2. The double closed loop dc governing system research backgroundDc speed control is the modern electric development of an earlier technology. In the the combination of modern power electronics the prosperity of the electric drive controldrive automatic control system in the1960

21、 s, with the emergence of thyristor,and control theory, computer promotestechnology research and application.Thyristor - dc motor speed control system for modern industry provides a highlyefficient, high performance power. Although at present the rapid development of ac speed regulation, the more ha

22、sten is mature ac (alternating current) technique, and the efficiency of ac motor and maintainability, the ac speed regulation is widely welcomed by users. But the dc motor speed control system, with its excellent speed regulating performance still has broad market, and based on feedback control the

23、ory of dc speed regulation principle is the basis for the control of ac speed regulation. Now the dc and ac speed regulating device is digital, using chips and software have different features, but the basic control principle has its generality.There is a big risk for those in the actual process of

24、debugging or experimental system of expensive, generally does not allow experiments to design a good system directly. Through experimental studies, however, do not is not to design a good system directly on the actual production. So you must be on the simulation experiment research. , of course, in

25、some cases can construct a set of device physics experiment, but this method is very time consuming and cost high, and in some cases, physical simulation is almost impossible. In recent years, with the rapid development of computer, USES the computer control system for mathematical simulation method

26、 has been adopted by people.But for a long time, the simulation in the field of research is focused on the establishment of simulation model is a process, namely the system model is established to design an algorithm. To make the system model for the computer, and then compiled into a computer progr

27、am, and run on the computer. Thus produced a variety of simulation algorithms and simulation software.Due to the model establishment and simulation study is less, so modeling often takes a long time, at the same time, the analysis of simulation results must rely on experts, and decision makers is a

28、lack of direct guidance, thus greatly hindered the popularization and application of simulation technology.Provide dynamic simulation tool Simulink in MATLAB, is the most powerful in many simulation software, one of the most outstanding, the most easy to use. It effectively solves the above problems

29、 in simulation technology. In Simulink, the modeling of the system will become very simple, and the simulation process is interactive, so you can casually change the simulation parameters, and can immediately get the modified results. In addition, the use of MATLAB in various analysis tools, also ca

30、n be the result of the simulation analysis, and visualization.Simulink can go beyond the ideal linear model to explore more realistic models of nonlinear problem, such as friction and air resistance in the real world, the gear meshing and other natural phenomena; Simulation to the macroscopic object

31、s, it can be to micro molecules and atoms, it can be the type of object modeling and simulation is extensive, can is a mechanical, electronic and other real entity, also can be the ideal system, but the simulation of the complexity of the dynamic system but can small, can be continuous, discrete or

32、hybrid. Simulink can make your computer into a lab, use it for all kinds of existing in reality, does not exist, or even opposite system modeling and simulation.Since the 70 s, both at home and abroad in the field of electric drive extensively adopted "thyristor dc motor speed regulation techno

33、logy" (hereinafter referred to as the V - Mspeed control system). Although today's power semiconductor converter technology has been the development by leaps and bounds, but V - Msystem in industrial production are still occupies a considerable proportion. In the process of engineering desi

34、gn and theoretical study, to be exposed to a lot of speed control system analysis, synthesis and design problem. Traditional research methods mainly include analytical method, experimental method and simulation experiment, in which they have their respective advantages in the former two methods at t

35、he same time it still hasdifferent limitations. Along with thedevelopment of production technology, the electrical driving and braking, and reversing and speed control precision, speed range, static characteristic and dynamic response, etc, put forward the higher request, this requires extensive use

36、 of speed control system. As a result of the dc motor speed control and torque control performance is good, since the 1930 s, started using dc speed regulating system. Its development process is this: by the rotation of the earliest development of converter unit control for enlarger, magnetic amplif

37、ier control;Further, in the stillness of the thyristor converter device and analog controller realize dc speed regulation; Later, with controlled rectifier and high-power transistors of PWM control circuit to realize the digital dc speed control, make the system quickness, controllability and econom

38、y enhances unceasingly. The continuousimprovement of speed regulating performance, make the dc speedregulation system has a very wide range of applications.In industrial production, the need of high performance speed control of electric drive occasion, the dc speed regulation system, especially the

39、double closed loop dc speed control system play an extremely important role. Speed and current double closed-loop speed control system is in the 1960 s of a new type of speed control system in foreign countries. Since the 70 s, in our country's metallurgical, mechanical, manufacturing and printi

40、ng and dyeing industry is increasingly widely used. Double closed loop speed control system is developed by the automatic single closed-loop speed control system. It introduced through two speed and current regulator respectively speed negative feedback and currentfeedback, and constitute the double

41、 closed loop system. Effectively improve the motor performance. This design mainly adopts three-phase fully-controlled bridge rectifier circuit of dc motor power supply, and through the engineering design method for speed regulator and current regulator parameters calculation in order to achieve the

42、 speed of current double closed loop speed regulation system of a tributary of the overall implementation.3 working principle of the systemThe system is mainly composedof the main switch, the motor excitation circuit, thyristor speed control circuit (including tachometer circuit), rectifier filter c

43、ircuit, flat wave reactor discharge circuit, energy consumption braking circuit, the realization of the whole system is controlled by closed-loop PI regulator. When the main switch is closed, the small pulse current in single-phase ac gain control of thyristor speed control circuit, and the rectifie

44、r bridge, the filter for the generator and the flat wave reactor, and at the same time, through the rectifier excitation circuit, ac motor inspired to begin to work. In regulating the speed of the trigger circuit potentiometer RP1 by PIC16F877 to decline, the decline of AN1input voltage output contr

45、ol point of view, and the brake pipe flow Angle, and the main circuit to improve the output voltage, and the motor speed increase, increase and speed measuring circuit of the output voltage, and motor in setting speed, stable operation range by the function of the PI regulator.4 . All parts of the s

46、ystem design of the circuit4.1 the design of the main circuitFor components in the circuit parameter Settings, as shown in figure 3. Press the start button switch SW, make the contactor of KM and KM circuit, the normally open contact closure, the normally closed contact is opened, and start button s

47、elf-locking, main circuit connection, and thyristor speed control circuit by changing the two-way thyristor control Angle control of ac output, and dc rectifier and filter is obtained by a bridge, at the same time, the motor through rectifier excitation circuit have incentives to work. Limit the dc

48、pulse in the circuit connection flat wave reactor, and the resistance R3 provide discharge circuit flat wave reactor snapped in the main circuit. To speed up the braking, energy consumption braking is to use the equipment, and brake parts by the resistor R4 and normally closed contact of main circui

49、t contactor.The excitation of the motor is from single power rectifier circuit, and to prevent uncontrollable high speed accident caused by motor excitation loss, in the drive circuit, in series current relay KA, and current action can by adjusting the potentiometer RP.4.2 the design of the thyristo

50、r trigger circuitPoint A and point B in the main circuit of voltage to 20 v through A transformer, then rectifier, about 100 and A half hours of signal occurred in these two points, and through the signal points with NPN R6 and R7 amplification, the triode had A zero pulse collector, and capture zer

51、o channel pulse rising along the CCPImodule and pay attention to happen the first time, catch the zero pulse falling edge, and the time difference between the two is zero pulse width, and the value is half of the midpoint of pulse, by capturing mode, we can accurately obtain the actual passing zero

52、communication, and at the sametime, we can use the ADCanalog/digital conversion module will analog voltage of PIC16F877 pin RA1 / AN1 set by the Angle of the thyristor control value (set motor speed value), change the set point potentiometer RP1 and change accordingly set the value of the thyristor

53、control Angle, and the output value tachometer circuit by pin RA1 / AN1 PIC16F877 input, and values as feedback speed by A/D conversion. In the single-chip microcomputer system oscillation frequency is 4 MHZ, and according to the characteristics of PIC16F877 ordering cycle, the resolution of the thy

54、ristor control Angle is a quarter of a single chip microcomputer frequency of oscillation of the reciprocal of 1 mu, i.e., in the power of 10 ms half wave time, control Angle can reach 10000 steps, fully realize the stepless smooth control of the motor.4.3 speed measuring circuit designTachometer ci

55、rcuit encoded by optical disk accretion and the motor rotor and electrical pulse shaping circuit. Electrical pulse frequency fixed ratio and the rotational speed of the motor, and through the amplification plastic, by the optical encoder output electrical impulses from pin RC0 / T1CK1 input PIC16F87

56、7 as standard TTL level, by counting TMR1 counter calculation speed, and compare with the preset rotating speed and rotating speed difference, the difference with PIC16F877 singlechip microcomputer PI operation control value increases, and thethyristor control Angle to change effective CCP2 motor vo

57、ltage of two ports, so as to control speed.5 ConclusionThe study of the subject - dc motor double closed loop speed regulation system dynamic characteristic research and simulation, is based on the engineering design method of engineering design method to design dc motor speed and current double closed-loop speed control system. According to the basic equation for dc motor speed control system of mathematic model,