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1、<p><b> 畢業(yè)設(shè)計(jì)(論文)</b></p><p><b> 外文翻譯</b></p><p> 題 目 直流電動(dòng)機(jī)無環(huán)流</p><p><b> 可逆調(diào)速系統(tǒng)設(shè)計(jì)</b></p><p> 專 業(yè) 電氣工程與自動(dòng)化 <
2、/p><p> 班 級(jí) 2008級(jí)(2)班 </p><p> 學(xué) 生 鄭凌峰 </p><p> 指導(dǎo)教師 杜軍 </p><p><b> 重慶交通大學(xué)</b></p><p><b> 2012 年<
3、/b></p><p> 直流串激電機(jī)速度控制的仿真和建模</p><p><b> 摘要:</b></p><p> 直流系列電機(jī)是機(jī)電一體化中需要高轉(zhuǎn)矩/速度比應(yīng)用的首選。本文介紹了一個(gè)基于微控制器和IGBT的開環(huán)直流電動(dòng)機(jī)速度控制系統(tǒng)的設(shè)計(jì)和實(shí)施。這里使用的仿真工具,可以預(yù)測(cè)的機(jī)械和電子模塊組成的系統(tǒng)的動(dòng)態(tài)行為。本文提供的仿真
4、結(jié)果與實(shí)驗(yàn)室測(cè)量結(jié)果驚人的相似。</p><p> 1.介紹 直流電動(dòng)機(jī)通常被需要高轉(zhuǎn)矩/速度比牽引應(yīng)用選中。例如輪椅,高爾夫球車,吊機(jī),起重機(jī),驅(qū)動(dòng)器武器等。包括一個(gè)典型的應(yīng)用:人類操作員通過油門踏板或一根杠桿控制直流電動(dòng)機(jī)。按照踏板或杠桿的位置,由電子系統(tǒng)調(diào)節(jié)電力送入電機(jī)的過程,習(xí)慣上被稱為速度控制。這種控制既可以是在閉環(huán)或開環(huán)配置中。雖然閉環(huán)系統(tǒng)所需的精度高,但是有很多情況下,一個(gè)開環(huán)系統(tǒng)就
5、足夠了。本文關(guān)注的是后者的。</p><p> 一個(gè)典型的直流電機(jī)調(diào)速系統(tǒng)往往有由其內(nèi)部模擬電路生成和處理內(nèi)部的信號(hào),</p><p> 而且它的功率驅(qū)動(dòng)階段有幾個(gè)并聯(lián)的MOSFET模塊。通過更換或補(bǔ)充模擬與數(shù)字電路的功能,或者由單個(gè)IGBT替換Mosfet并聯(lián)模塊,改進(jìn)的控制,從而導(dǎo)致更可靠,成本更低,更簡單生產(chǎn)。因此,建議在基于IGB的開環(huán)數(shù)字速度控制上發(fā)展。不過,本文的主要目的是
6、加速提出這種方法的人如何在樣機(jī)上進(jìn)行速度控制的。</p><p> 電機(jī)原型通常是在試驗(yàn)和錯(cuò)誤的過程中實(shí)現(xiàn)的,大部分時(shí)間,結(jié)果是非常昂貴和費(fèi)時(shí)。這個(gè)缺點(diǎn)可以通過適當(dāng)結(jié)合計(jì)算機(jī)模擬和實(shí)驗(yàn)室測(cè)試大大緩解。在連接電動(dòng)馬達(dá)和其調(diào)速系統(tǒng)以前可以用很簡單的電機(jī)或電子控制模塊做模型。</p><p> 2. 建議設(shè)計(jì)為直流電動(dòng)機(jī)的速度控制</p><p> 當(dāng)前數(shù)字技術(shù)提
7、供了直流電動(dòng)機(jī)生成PWM開關(guān)信號(hào)的功能和處理保護(hù)信號(hào)的功能。一個(gè)處理器取代模擬模塊和與之相關(guān)的幾個(gè)分立器件??刂葡到y(tǒng)的物理尺寸和生產(chǎn)成本將因此而被降低,與此同時(shí),其可靠性得以提高。</p><p> 圖1.踏板信號(hào)調(diào)理電路.</p><p> 要產(chǎn)生PWM開關(guān)信號(hào),Vcond從圖1電路輸入控制器的第一個(gè)A / D轉(zhuǎn)換器輸入。 vcond因此離散成256份的水平,他們每個(gè)作為一個(gè)微控制器
8、E2PROM的地址。相應(yīng)的存儲(chǔ)單元包含脈沖的持續(xù)時(shí)間。因此,根據(jù)Vcond脈沖寬度在256份中不相等。這里正在實(shí)施的原型,采用離散的線性變化。然而這種線性特性,可以很容易地改變.</p><p> 其注入到電力驅(qū)動(dòng)器門之前,PWM信號(hào)首先通過光電隔離器和經(jīng)過一個(gè)緩沖的階段(見圖2)。在電力電子方面,一個(gè)完整的直流到直流H橋轉(zhuǎn)換器有四個(gè)IGBT的器件,。然而,這里介紹的,是H橋一個(gè)分支的形式(見圖 3)。這個(gè)分支
9、被當(dāng)作一個(gè)降壓轉(zhuǎn)換器。</p><p><b> 圖2.柵極驅(qū)動(dòng)器。</b></p><p><b> 圖3.功率輸出級(jí).</b></p><p> 除了防止損失的踏板,其他保護(hù)功能在需要電壓傳感器以及電流和溫度傳感器的產(chǎn)品中實(shí)現(xiàn)。這些設(shè)備提供的模擬信號(hào),然后送入微控制器。通過其附加的A / D轉(zhuǎn)換器輸入和監(jiān)控微控制
10、器的程序。</p><p> 3. 使用模擬行為模塊的直流串激電機(jī)建模</p><p><b> 3.1汽車方程</b></p><p> DC系列電機(jī)的機(jī)電行為方程描述如下。電氣平衡方程[2]和[8]</p><p><b> [1]</b></p><p> 其
11、中Vs是串聯(lián)兩個(gè)串聯(lián)繞組的電壓,EA是感應(yīng)電動(dòng)勢(shì)(EMF),Rt是總的串聯(lián)電阻,Is是通過繞組電流,LT是總的串聯(lián)電感。 EA的磁通量φ和角speedω的關(guān)系是[2]和[8]</p><p><b> [2]</b></p><p> 以下列方式,直流電機(jī)制定的電磁轉(zhuǎn)矩取決于Is和φ,其中,Ka是電機(jī)常數(shù)</p><p><b>
12、 [3]</b></p><p> 力矩平衡方程[2]和[8]:</p><p><b> [4]</b></p><p> 其中TL是負(fù)載轉(zhuǎn)矩,B是恒定粘性摩擦,J為電機(jī)的轉(zhuǎn)子和軸慣性。磁通和繞組中的電流通過本機(jī)的磁化曲線表示與[2]和[5]有關(guān):</p><p><b> [5]<
13、;/b></p><p> 函數(shù)f(IS)一般包括飽和度和滯后效應(yīng)。</p><p> 3.2DC系列電機(jī)的模擬行為建模</p><p> ?。?),(2),(3),(4)(5)提供了一個(gè)適合的直流串激電機(jī)的數(shù)學(xué)模型,圖4為電機(jī)反導(dǎo)實(shí)施。</p><p> 圖4.電機(jī)反導(dǎo)實(shí)施。</p><p> 圖4中1
14、模塊是對(duì)應(yīng)EQ的要素的系列分支。請(qǐng)注意,EMF項(xiàng)“EA”模塊2注入到這個(gè)分支單位增益電壓控制電壓源。也包括在這個(gè)分支是單位增益電流控制電壓源,電流傳感器。感應(yīng)電流,需要磁通φ和電磁轉(zhuǎn)矩TEM兩者的計(jì)算。</p><p> 磁通量實(shí)際上是EA計(jì)算的中間變量。結(jié)合(5)和(2)。</p><p><b> [6] </b></p><p>
15、電動(dòng)機(jī)的磁化特性通常是提供了一個(gè)EA點(diǎn) ——在一個(gè)固定值ω0=180.6 RAD/角速度獲得。此值通常對(duì)應(yīng)于電機(jī)的額定銘牌速度。讓表示Ea0在ω0這一特點(diǎn)。 (6)根據(jù)不同的價(jià)值為ω[2]:</p><p><b> [7] </b></p><p> Mn除了到Ea0外。由于粘性摩擦Bω長期被忽視,[8]為這個(gè)方程收益:</p><p>
16、;<b> [8]</b></p><p> 很明顯,從圖3中的模塊4實(shí)現(xiàn)這最后方程。結(jié)合(2)(3)到(7)獲得的電磁轉(zhuǎn)矩為以下表達(dá)式</p><p><b> [9] </b></p><p> 模塊3,終于實(shí)現(xiàn)了這個(gè)最后方程</p><p> 上述電機(jī)模型來重現(xiàn)可用1馬力系列直流電動(dòng)
17、機(jī)運(yùn)行。首先,測(cè)量這種電機(jī)的參數(shù)LT,RT和J。然后,磁化特性Ea0 Vs Is集合成80點(diǎn)繪制在圖5上,接下來,所有這些數(shù)據(jù)被應(yīng)用圖4模型。最后,進(jìn)行各種實(shí)驗(yàn),電機(jī)及其反導(dǎo)模型。這些實(shí)驗(yàn)設(shè)計(jì),以便能夠測(cè)量細(xì)化的參數(shù)。此外,ABM電機(jī)模型,在實(shí)際提供的某些特殊儀器,如測(cè)功機(jī)中缺乏用于模擬變量和參數(shù)的值如下:RT= 55MΩ;= 0.06 kgm2,VS= 12V(A和A'之間的張力),查看MATHML源μF和寄生電感,忽視L
18、C。繞線電感LT是一個(gè)值,只是頻率不同。從繞線的階躍響應(yīng)實(shí)驗(yàn)中得出LT的以下兩個(gè)值估計(jì):LT=75μH的2100赫茲和LT=150μH的2500赫茲。中頻LT是使用線性插值計(jì)算。表1列出了這些值。</p><p> 表1.銘牌和實(shí)測(cè)值的直流電機(jī)</p><p> 3.3 SPICE模型速度控制的建議</p><p> 圖1 系統(tǒng)化的建議直流系列電動(dòng)機(jī)速度控制的
19、SPICE模型。它包括四個(gè)基本構(gòu)建模塊:踏板信號(hào)調(diào)理器,微控制器,柵極驅(qū)動(dòng)器和功率輸出級(jí)。除了微控制器,所有這些模塊代表了SPICE模型的制造商詳細(xì)的使用了半導(dǎo)體器件的細(xì)節(jié)。</p><p> 我不認(rèn)為一個(gè)微控制器的詳細(xì)表示是有必要的,此外,它是在這項(xiàng)工作中使用臺(tái)式電腦是不現(xiàn)實(shí)的。這個(gè)選擇代表PWM功能用來代替通過一個(gè)矩形波發(fā)生器和寬度是的256脈沖,根據(jù)不同步驟的輸出信號(hào)控制調(diào)節(jié)器踏板。再被注入到電機(jī)模型中,
20、這些PWM信號(hào)通過門的驅(qū)動(dòng)和輸出功率機(jī)建立模型。這里應(yīng)該提到,除了對(duì)踏板信號(hào)的保護(hù),其他保護(hù)功能的微控制器及其相關(guān)電路的損失不模擬。圖1 系統(tǒng)化的建議直流系列電動(dòng)機(jī)速度控制的SPICE模型。它包括四個(gè)基本構(gòu)建模塊:踏板信號(hào)調(diào)理器,微控制器,柵極驅(qū)動(dòng)器和功率輸出級(jí)。除了微控制器,所有這些模塊代表了SPICE模型的制造商詳細(xì)的使用了半導(dǎo)體器件的細(xì)節(jié)。</p><p><b> 4.結(jié)論</b>
21、</p><p> 本文提出一個(gè)復(fù)雜的電子,機(jī)電原型開發(fā)方法。它主要包括與實(shí)驗(yàn)室檢測(cè)相結(jié)合的計(jì)算機(jī)模擬。這種方法得到了進(jìn)一步的應(yīng)用在開發(fā)一個(gè)1馬力直流系列電動(dòng)機(jī)的速度控制系統(tǒng)。這里采用的仿真工具是OrCAD及其ABM實(shí)用程序“的PSPICE”。</p><p> 雖然PSPICE中允許的電子和電力電子模塊的建立,包括制造商提供的詳細(xì)模塊。但是ABM的實(shí)用程序,使電機(jī)的機(jī)電特性的描述得更
22、加準(zhǔn)確。從而使連接模擬的電機(jī)和電機(jī)速度控制也因此成為可能。在這方面模擬和實(shí)驗(yàn)室測(cè)試兩者得到的數(shù)據(jù)一直令人滿意。</p><p> 前人(Chee-Mun, INTUSOFT, HDLA Mentor)的研究結(jié)果,已經(jīng)模擬速度控制,將其耦合到很簡單的樹枝型電機(jī)模型。更現(xiàn)實(shí)的電機(jī)模型在ABM模型中占有較多的比例。其他開發(fā)者可以進(jìn)一步采用他們,本文提供了必要的數(shù)據(jù)重構(gòu)結(jié)果如下。此外,第三方甚至可以修改該相對(duì)簡單的模型
23、,使其相對(duì)容易適應(yīng)特殊需要和其他的發(fā)展。模擬結(jié)果已經(jīng)允許了這個(gè)實(shí)驗(yàn),甚至在它被調(diào)試之前,速度控制已經(jīng)被調(diào)試。例如,幫助建立模擬系統(tǒng)不能啟動(dòng)50%以上的占空比</p><p> 整體經(jīng)驗(yàn)與方法的提出,使得開發(fā)時(shí)間和成本大幅度降低。模擬與實(shí)驗(yàn)工作相結(jié)合,甚至缺乏某些專門儀器,如測(cè)功機(jī)。他們還啟用了無法訪問變量,如電動(dòng)勢(shì)的監(jiān)測(cè)。這是個(gè)顯著的事實(shí)是,在這個(gè)項(xiàng)目中沒有一個(gè)電力電子器件燒毀。</p>&l
24、t;p> 最后,正在進(jìn)行的工作是保持一個(gè)完整的定速發(fā)展的速度控制,以及對(duì)應(yīng)用這直流電機(jī)在不同的維度的ABM模型提供了可能需要修改,以包括額外的功能,如粘滯摩擦、滯后性和頻率依賴性的線繞的電感。</p><p> Simulation and construction of a speedcontrol for a DC series moto</p><p><b>
25、 Abstract</b></p><p> DC 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
26、 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
27、 consisting of mechanic and electronic modules. The simulations provided along the paper show a satisfa</p><p> 1. Introduction</p><p> DC series motors usually are selected for traction appli
28、cations 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 ac
29、celerator pedal or a lever. The electronic system regulating the electric power fed into a motor, in accordance with a pedal or lever's position, customarily is referred to as speed control. Such a system can be eith
30、er in cl</p><p> 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]. T
31、his 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 improve
32、d control would thus result more reliable, less costly and much simpler to produce. An open</p><p> Mechatronic prototypes usually are implemented by a trial and error process which, most of the time, ends
33、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 m
34、otor and its speed control has been done before by applying very simple models for the motor and/or for the electronic control modules [1], [8] and [12].</p><p> 2. Proposed design for a DC motor
35、speed control</p><p> Current 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
36、 the DC motor speed control.</p><p> Fig. 1. Pedal signal conditioning circuit.</p><p> To generate the PWM switching signals, Vcond from Fig. 1 circuit is fed into the micro-controller
37、39;s first A/D converter input. Vcond is thus discretized into 256 levels, each one of them is taken as an address for the micro-controller's E2PROM. The corresponding memory cell contains the intended duration of th
38、e 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</p><p> Before t
39、heir 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,
40、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 sh
41、own in Fig. 3. This branch is made to perform as a s</p><p> Fig. 2 Gate driver.</p><p> Fig. 3 Power output stage.</p><p> In addition to the protection against loss o
42、f 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 mic
43、ro-controller via its additional A/D converter inputs and their monitoring is made by the micro-controller's program.</p><p> 3. DC series motor modeling using analog behavioral modules</p><p
44、> 3.1. Motor equations</p><p> The equations that describe the electromechanical behavior of a DC series motor are given as follows. The electrical equilibrium equation is [2] and [8]:</p&g
45、t;<p><b> (1) </b></p><p> 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 curr
46、ent through the windings and Lt is the total series inductance. The relation of Ea with magnetic flux φ and angular speed ω is [2] and [8]</p><p><b> (2) </b></p><p> whe
47、re Ka is a motor constant. The electromagnetic torque developed by the DC motor depends on Is and on φ in the following manner:</p><p><b> (3) </b></p><p> The torque balance equat
48、ion is [2] and [8]:</p><p><b> (4) </b></p><p> where TL is the load torque, B is the viscous friction constant and J is the motor's rotor and shaft inertia. The magn
49、etic flux and the windings current are related through the machine's magnetization curve which is denoted as follows [2] and [5]:</p><p><b> (5) </b></p><p> Function
50、 f(Is) in general includes saturation and hysteresis effects.</p><p> 3.2. Analog behavioral modeling of a DC series motor</p><p> (1), (2), (3), (4) and (5) provide a mathematical m
51、odel for a DC series motor suitable for the purposes of this paper [2] and [5]. The ABM implementation of this model is shown in Fig. 4.</p><p> Fig. 4. ABM implementation of the motor.</p
52、><p> 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.
53、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 φ and the e
54、lectromagnetic torque Tem.</p><p> The magnetic flux actually is an intermediate variable for the calculation of Ea. On combining (5) and (2)</p><p><b> (6)</b></p>
55、<p> The magnetization characteristic of an electric motor usually is provided as a set of points of Ea vs. Is obtained at a fixed value ω0=180.6 rad/s of the angular speed. This value usually corresponds to the
56、motor's nominal or nameplate speed. Let Ea0 denote this characteristic at ω0. According to (6), for a different value of ω[2]:</p><p><b> (7)</b></p><p> In addition to Ea0, th
57、e other input to module 2 is the angular speed calculated by module 4 that corresponds to Eq. (4). On neglecting Bω, the viscous friction term, this equation yields [8]:</p><p><b> (8)</b></p
58、><p> 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</p><p>&l
59、t;b> (9)</b></p><p> Module 3, finally, implements this last equation.</p><p> The above-described motor model was used to reproduce the operation of an available 1 hp DC series moto
60、r. 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
61、 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</p><p> Table 1. Name plate
62、and measured values of the DC motor</p><p> 3.3. SPICE model of the proposed speed control</p><p> Fig. 1 schematizes the SPICE model of the proposed DC series motor speed control. It consists
63、 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 provide
64、d SPICE models for the semiconductor devices being used.</p><p> A detailed representation of the micro-controller is not deemed necessary and, besides, it is unrealistic for the desktop computer being used
65、 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.
66、Before being injected into the motor model, these PWM signals are passed through the gate driver and the power output models. It should be </p><p> The detailed diagram for the pedal signal conditioner is t
67、he one provided in Fig. 1, while the diagrams for the gate driver and for the power output stage are provided in Fig. 2 and Fig. 3 An advantage of using SPICE for the modeling of these blocks is the access to a
68、 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 manufacturer's web information site. Before its p
69、hysical implemen</p><p> 4. Conclusions</p><p> A methodology for developing complex electronic–electromechanical prototypes has been presented in this paper. It consists essentially in combin
70、ing 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
71、 ABM utilities.</p><p> While PSPICE has permitted a detailed representation of the electronics and power electronics modules which include manufacturers' supplied modules, the ABM utilities have enable
72、d the accurate description of the motor's electromechanical features. The conjunct simulation of the motor and its speed control has thus been possible. The agreement attained here between simulations and laboratory
73、tests has been satisfactory.</p><p> Previous works by others (Chee-Mun, INTUSOFT, HDLA Mentor) have simulated speed controls coupled to very simple (one branch) motor models. The ABM model provided here ac
74、counts for more realistic motor features. It can be further adopted by other developers and the paper provides the necessary data for reproducing the results presented here. Third parties, in addition, may even modify th
75、is model with relative ease to suit the particular needs for other developments. The simulations have permitted</p><p> The overall experience with the methodology presented is that it has helped reducing d
76、evelopment time and costs substantially. The simulations, when combined with experimental work, even supplied the lack of certain specialized instrumentation, like dynamometers. They also enabled the monitoring of inacce
77、ssible variables like the electromotive force. A remarkable fact is that not a single power electronic device was burned during this project.</p><p> Finally, ongoing work is in the development of a full H-
78、bridge speed control, as well as on applications of this to DC motors of different dimensions where the ABM model provided here may have to be modified to include additional features, like viscous friction, hysteresis an
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