外文翻譯---直流電動機調(diào)速控制

1、<p><b>　　附錄D 外文翻譯</b></p><p>　　Speed Control of DC Motor</p><p>　　Abstract Conditioning system is characterized in that output power to maintain stability. Different speed con

2、trol system can use a different brake system, high starting and braking torque, quick response and quick adjustment range of degree requirements of DC drive system, the use of the electric braking mode. Depends on the sp

3、eed control of DC motor armature voltage and flux. To zero speed, or U = 0 or Φ = ∞. The latter is impossible, it only changes through the armature voltage to reduce spee</p><p>　　Keyword DC Speed Feedback

4、 Brake</p><p>　　Regulator Systems</p><p>　　A regulator system is one which normally provides output power in its steady-state operation.</p><p>　　For example, a motor speed regulat

5、or maintains the motor speed at a constant value despite variations in load torque. Even if the load torque is removed, the motor must provide sufficient torque to overcome the viscous friction effect of the bearings. Ot

6、her forms of regulator also provide output power; A temperature regulator must maintain the temperature of, say, an oven constant despite the heat loss in the oven. A voltage regulator must also maintain the output volta

7、ge constant despite variat</p><p>　　Electrical Braking</p><p>　　In many speed control systems, e.g., rolling mills, mine winders, etc., the load has to be frequently brought to a standstill and

8、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 mechan

9、ical braking, but this is not feasible with large speed controllers since it is difficult and costly to remove the heat generated.</p><p>　　The various methods of electrical braking available are:</p>

10、<p>　　Regenerative braking.</p><p>　　Eddy current braking.</p><p>　　Dynamic braking.</p><p>　　Reverse current braking(plugging)</p><p>　　Regenerative braking is t

11、he 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

12、. 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 re

13、generation. In the Ward-Leonard met</p><p>　　Eddy current braking can be applied to any machine, simply by mounting a copper or aluminum disc on the shaft and rotating it in a magnetic field. The problem of

14、removing the heat generated is severe in large system as the temperature of the shaft, bearings, and motor will be raised if prolonged braking is applied.</p><p>　　In dynamic braking, the stored energy is di

15、ssipated in 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 voltag

16、e 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. Th

17、e electrical ener</p><p>　　DC Motor Speed Control</p><p>　　The basis of all methods of DC motor speed control is derived from the equations:</p><p>　　the terms having their usual me

18、anings. If the IaRa drop is small, the equations approximate to or 。Thus, control of armature voltage and field flux influences the motor speed. To reduce the speed to zero, either U=0 orΦ=∞.The latter is inadmissible;

19、 hence control at low speed is by armature voltage variation. To increase the speed to a high value, either U is made very large or Φis reduced. The latter is the most practical way and is known as field weakening. Combi

20、nations of the two are used w</p><p>　　A Single-Quadrant Speed Control System Using Thyristors</p><p>　　A single-quadrant thyristor converter system is shown in Fig.1.For the moment the reader s

21、hould ignore the rectifier BR2 and its associated circuitry (including resistor R in the AC circuit), since this is needed only as a protective feature and is described in next section.</p><p>　　Fig.1 Thyris

22、tor speed control system with current limitation on the AC side</p><p>　　Since the circuit is a single-quadrant converter, the speed of the motor shaft (which is the output from the system) can be controlled

23、 in one direction of rotation only. Moreover, regenerative braking cannot be applied to the motor; in this type of system, the motor armature can suddenly be brought to rest by dynamic braking (i.e. when the thyristor ga

24、te pulses are phased back to 180o, a resister can be connected across the armature by a relay or some other means).</p><p>　　Rectifier BR1 provides a constant voltage across the shunt field winding, giving a

25、 constant field flux. The armature current is controlled by a thyristor which is, in turn, controlled by the pulses applied to its gate. The armature speed increases as the pulses are phased forward (which reduces the de

26、lay angle of firing), and the armature speed reduces as the gate pulses are phased back.</p><p>　　The speed reference signal is derived from a manually operated potentiometer (shown at the right-hand side of

27、 Fig.23.1), and the feedback signal or output speed signal is derived from the resistor chain R1 R2, which is connected across the armature. (Strictly speaking, the feedback signal in the system in Fig.23.1 is proportion

28、al to the armature voltage, which is proportional to the shaft speed only if the armature resistance drop, IaRa, is small. Methods used to compensate for the IaRa drop are</p><p>　　A feature of DC motor driv

29、es is that the load presented to the supply is a mixture of resistance, inductance, and back EMF Diode D in Fig.1 ensures that the thyristor current commutates to zero when its anode potential falls below the potential o

30、f the upper armature connection, in the manner outlined before. In the drive shown, the potential of the thyristor cathode is equal to the back EMF of the motor while it is in a blocking state. Conduction can only take p

31、lace during the time interval when</p><p>　　References:</p><p>　　Fig.2 Illustrating the effect of motor back EMF on the</p><p>　　Peak inverse voltage applied to the thyristor</p&

32、gt;<p>　　Fig.3 Armature voltage waveforms</p><p>　　The waveforms shown in Fig.2 are idealized waveforms as much as they ignore the effects of armature inductance,commutator ripple,etc.Typical armature

33、 voltage waveforms are shown in Fig.3.In this waveform the thyristor is triggered at point A, and conduction continues to point B when the supply voltage falls below the armature back EMF.The effect of armature inductanc

34、e is to force the thyristor to continue to conduct until point C,when the fly-wheel diode prevents the armature voltage from revers</p><p>　　References</p><p>　　1.Landau ID(1999)From robust cont

35、rol to adaptive control.Control Eng Prac 7:1113–1124</p><p>　　2.Forssell U,Ljung L(1999)Closed-loop identification revisited. Automatica 35:1215–1241</p><p>　　3.So¨derstro¨m T,Stoica P

36、(1989)System identification.Prentice Hall,Cambridge,UK</p><p>　　4.Horng JH(1999)Neural adaptive tracking control of a DC motor.Information Sci 118:1–13</p><p>　　5.Lyshevski SE(1999)Nonlinear con

37、trol of mechatronic systems with permanent-magnet DC motors.Mechatronics 9:539–552</p><p>　　6.Yavin Y,Kemp PD(2000)Modeling and control of the motion of a rolling disk:e?ect of the motor dynamics on the dyna

38、mical model.Comput Meth Appl Mech Eng 188:613–624</p><p>　　7.Mummadi VC(2000)Steady-state and dynamic performance analysis of PV supplied DC motors fed from intermediate power converter.Solar Energy Mater So

39、lar Cells 61:365–381</p><p>　　8.Jang JO,Jeon GJ(2000)A parallel neuro-controller for DC motors containing nonlinear friction.Neurocomputing 30:233–248</p><p>　　9.Nordin M,Gutman P(2002)Controlli

40、ng mechanical systems with backlash—a survey.Automatica 38:1633–1649</p><p>　　10.Wu R-H,Tung P-C(2002)Studies of stick-slip friction,pre-sliding displacement,and hunting.J Dyn Syst 124:111–117</p><

41、;p>　　11.Ogata K(1990)Modern control engineering.Prentice Hall,Englewood Cli?s,NJ</p><p>　　12.Slotine E,Li W(1991)Applied nonlinear control.Prentice Hall,Englewood Cli?s,NJ</p><p>　　13.Lee PL(

42、1993)Nonlinear process control:applications of gen-eric model control.Springer,Berlin Heidelberg New York</p><p><b>　　直流電動機調(diào)速控制</b></p><p>　　摘要 調(diào)節(jié)系統(tǒng)的特征在于能保持輸出功率的穩(wěn)定。不同的速度控制系統(tǒng)可以使用不同的制

43、動系統(tǒng)，在有高起、制動轉(zhuǎn)矩，快速響應(yīng)和快速度調(diào)節(jié)范圍要求的直流調(diào)速系統(tǒng)中，采用的是電氣制動的方式。直流電機的速度控制取決于電樞電壓和磁通。要將轉(zhuǎn)速降為零，或者U=0或Φ=∞。后者是不可能的，因此只可通過電樞電壓的變化來降低轉(zhuǎn)速。要將轉(zhuǎn)速增加到較高值，可以增大U或減小Φ。</p><p>　　關(guān)鍵詞 直流調(diào)速 反饋 制動</p><p><b>　　調(diào)節(jié)系統(tǒng)</b>&

44、lt;/p><p>　　調(diào)節(jié)系統(tǒng)是一類通常能提供穩(wěn)定輸出功率的系統(tǒng)。</p><p>　　例如，電機速度調(diào)節(jié)器要能在負(fù)載轉(zhuǎn)矩變化時仍能保持電機轉(zhuǎn)速為恒定值。即使負(fù)載轉(zhuǎn)矩為零，電機也必須提供足夠的轉(zhuǎn)矩來克服軸承的粘滯摩擦影響。其他類型的調(diào)節(jié)器也提供輸出功率，溫度調(diào)節(jié)器必須保持爐內(nèi)的溫度恒定，也就是說，即使?fàn)t內(nèi)的溫度散失也必須保持爐溫不變。一個電壓調(diào)節(jié)其也必須保持負(fù)載電流值變化時輸出電壓值恒定。對

45、于任何一個提供一個輸出，例如，速度、溫度、電壓等的系統(tǒng)，在穩(wěn)態(tài)下必須存在一個誤差信號。</p><p><b>　　電氣制動</b></p><p>　　在許多速度控制系統(tǒng)中，例如軋鋼機、礦坑卷揚機等這些負(fù)載要求頻繁地停頓和反向運動的系統(tǒng)。隨著減速要求，速度減小的比率取決于存儲的能量和所使用的制動系統(tǒng)。一個小型速度控制系統(tǒng)（例如所知的伺服積分器）可以采用機械制動，但這

46、對大型速度控制器并不可行，因為散熱很難而且很昂貴。</p><p>　　可行的各種電氣制動方法有：</p><p><b>　　回饋制動。</b></p><p><b>　　渦流制動。</b></p><p><b>　　能耗制動</b></p><p&g

47、t;<b>　　反接制動</b></p><p>　　回饋制動雖然并不一定是最經(jīng)濟(jì)的方式，但卻是最好的方式。負(fù)載中存儲的能量通過工作電機（暫時以發(fā)電機模式運行）被轉(zhuǎn)化成電能并返回到電源系統(tǒng)中。這樣電源就充當(dāng)了一個收容不想要的能量的角色。假如電源系統(tǒng)具有足夠的容量，在短時回饋過程中最終引起的端電壓升高會很少。在直流電機速度控制渥特-勒奧那多法中，回饋制動是固有的，但可控硅傳動裝置必須被排布的可

48、以反饋。如果轉(zhuǎn)軸速度快于旋轉(zhuǎn)磁場的速度，感應(yīng)電機傳動裝置可以反饋。由晶閘管換流器而來的廉價變頻電源的出現(xiàn)在變速裝置感應(yīng)電機應(yīng)用中引起了巨大的變化。</p><p>　　渦流制動可用于任何機器，只要在軸上安裝一個銅條或鋁盤并在磁場中旋轉(zhuǎn)它即可。在大型系統(tǒng)中，散熱問題是很重要的，因為如果長時間制動，軸、軸承和電機的溫度就會升高。</p><p>　　在能耗制動中，存儲的能量消耗在回路電阻器上。

49、用在小型直流電機上時，電樞供電被斷開，接入一個電阻器（通常是一個繼電器、接觸器或晶閘管）。保持磁場電壓，施加制動降到最低速。感應(yīng)電機要求稍微復(fù)雜一點的排布，定子繞組被從交流電源上斷開，接到直流電源上。產(chǎn)生的電能繼而消耗在轉(zhuǎn)子回路中。能耗制動應(yīng)用在許多大型交流升降系統(tǒng)中，制動的職責(zé)是反向和延長。</p><p>　　任何電機都可以通過突然反接電源以提供反向的旋轉(zhuǎn)方向（反接制動）來停機。在可控情況下，這種制動方法對所

50、傳動裝置都是使用的。它主要的缺點就是當(dāng)制動等于負(fù)載存儲的能量時，電能被機器消耗了。這在大型裝置中就大大增加了運行成本。</p><p><b>　　直流電機速度控制</b></p><p>　　所有直流電機速度控制的基本關(guān)系都可由下式得出：</p><p>　　各項就是她們通常所指的含義。如果IaRa很小，等式近似為或。這樣，控制電樞電壓和磁通

51、就可影響電機轉(zhuǎn)速。要將轉(zhuǎn)速降為零，或者U=0或Φ=∞。后者是不可能的，因此只可通過電樞電壓的變化來降低轉(zhuǎn)速。要將轉(zhuǎn)速增加到較高值，可以增大U或減小Φ。后者是最可行的方法，就是我們通常所知道的弱磁場。在要求速度調(diào)節(jié)范圍寬的場合可綜合使用這兩種方法。</p><p>　　使用晶閘管的單向速度控制系統(tǒng)</p><p>　　一個單相晶閘管逆變器系統(tǒng)如圖1所示。讀者應(yīng)該先忽略整流器BR2和它的相關(guān)電

52、路（包括交流回路中的電阻器R），因為這部分只有在具有保護(hù)功能時才需要，將在下一節(jié)介紹。</p><p>　　圖1 單向晶閘管逆變器系統(tǒng)</p><p>　　因為該電路是一個單向轉(zhuǎn)換器，只能在一個旋轉(zhuǎn)方向控制電機軸（系統(tǒng)的輸出）的速度。而且，回饋制動不能用于電機；在這種系統(tǒng)類型中，電機電樞可以通過電氣制動靜止（例如，當(dāng)晶閘管門極脈沖反向時，電阻可通過一個繼電器或其他裝置連接到電樞上）。<

53、;/p><p>　　整流器BR1給并聯(lián)勵磁繞組提供一個穩(wěn)定電壓，產(chǎn)生穩(wěn)定的磁通。電樞電流由一個晶閘管控制，該晶閘管又由加在它們極上的脈沖控制。脈沖正向時（減小起動延時角）電樞轉(zhuǎn)速增加，門極脈沖反相時電樞轉(zhuǎn)速減小。</p><p>　　速度參考信號可從人工操作的電位器（如圖1右側(cè)所示）上獲得，反饋信號或輸出轉(zhuǎn)速信號可從連接在電樞上的電阻器鏈上獲得。（嚴(yán)格的講，圖1系統(tǒng)中反饋信號只有當(dāng)電樞電組的壓

54、降很小時，才與軸轉(zhuǎn)速成正比的電樞電壓成正比。用于補償IaRa壓降的方法將在閱讀材料中討論。）因為電樞電壓是從一個晶閘管上獲得的，該電壓包括一系列由電容器C濾波的脈沖。速度參考信號與電樞電壓信號極性相反，以確保施加的都是負(fù)反饋。</p><p>　　直流電機裝置的一個特征就是需要供電的負(fù)載時電阻、電導(dǎo)的混合，并且在圖1中反電動勢二極管D確保當(dāng)晶閘管陽極電勢低于前面敘述的電樞連接方式的上限時，晶閘管電流應(yīng)換向為零。在

55、所示拖動系統(tǒng)中，當(dāng)晶閘管處于斷開狀態(tài)時，其陽極電勢等于電機反電動勢。只有在瞬時電源電壓大于反向電勢的間隔時它才會導(dǎo)通。圖2所示的檢測表明電機運行時晶閘管上峰值反向電壓大于峰值正向電壓。如圖所示，在晶閘管上串聯(lián)一個二級管，電路的反向關(guān)斷能力就會增強，所以允許使用低壓晶閘管。</p><p>　　圖2晶閘管對電機反電動勢的影響</p><p><b>　　圖3電樞電壓波形</b

56、></p><p>　　圖2所示的波形是理想的波形，因為忽略了電樞電感、換向器紋波等因素的影響。典型的電樞電壓波形如圖3所示。在該波形中，晶閘管在A點觸發(fā)，一直到B點電源電壓低于電樞反電動勢時導(dǎo)通。電樞電感的作用使晶閘管保持到C點飛輪二極管使電樞電壓反向之前導(dǎo)通。當(dāng)電感能量消失（D點），電樞電流為零，電壓恢復(fù)到它的正常水平，這個暫態(tài)過程最后穩(wěn)定在E點。點E、F之前的紋波是由換向器引起的紋波。</p&g