外文文獻(xiàn)及翻譯--三相異步電動機(jī)的幾種調(diào)速方式

1、<p><b>　　畢 業(yè) 論 文</b></p><p>　　外 文 文 獻(xiàn) 譯 文 及 原 文</p><p>　　學(xué) 生： </p><p>　　學(xué) 號： </p><p>　　院 （系）：

2、電氣與信息工程學(xué)院 </p><p>　　專 業(yè)： 電氣工程及其自動化 </p><p>　　指導(dǎo)教師： </p><p>　　2014 年 6 月 10 日</p><p><b>　　中文2340字</b></p><p>　

3、　三相異步電動機(jī)的幾種調(diào)速方式</p><p>　　三相異步電動機(jī)轉(zhuǎn)速公式為： n=60f/p(1-s)</p><p>　　從上式可見，改變供電頻率f、電動機(jī)的極對數(shù)p及轉(zhuǎn)差率s均可太到改變轉(zhuǎn)速的目的。從調(diào)速的本質(zhì)來看，不同的調(diào)速方式無非是改變交流電動機(jī)的同步轉(zhuǎn)速或不改變同步轉(zhuǎn)兩種。</p><p>　　在生產(chǎn)機(jī)械中廣泛使用不改變同步轉(zhuǎn)速的調(diào)速方法有繞線式電動機(jī)的

4、轉(zhuǎn)子串電阻調(diào)速、斬波調(diào)速、串級調(diào)速以及應(yīng)用電磁轉(zhuǎn)差離合器、液力偶合器、油膜離合器等調(diào)速。改變同步轉(zhuǎn)速的有改變定子極對數(shù)的多速電動機(jī)，改變定子電壓、頻率的變頻調(diào)速有能無換向電動機(jī)調(diào)速等。</p><p>　　從調(diào)速時的能耗觀點來看，有高效調(diào)速方法與低效調(diào)速方法兩種：高效調(diào)速指時轉(zhuǎn)差率不變，因此無轉(zhuǎn)差損耗，如多速電動機(jī)、變頻調(diào)速以及能將轉(zhuǎn)差損耗回收的調(diào)速方法（如串級調(diào)速等）。有轉(zhuǎn)差損耗的調(diào)速方法屬低效調(diào)速，如轉(zhuǎn)子串電

5、阻調(diào)速方法，能量就損耗在轉(zhuǎn)子回路中；電磁離合器的調(diào)速方法，能量損耗在離合器線圈中；液力偶合器調(diào)速，能量損耗在液力偶合器的油中。一般來說轉(zhuǎn)差損耗隨調(diào)速范圍擴(kuò)大而增加，如果調(diào)速范圍不大，能量損耗是很小的。</p><p>　　一、變極對數(shù)調(diào)速方法</p><p>　　這種調(diào)速方法是用改變定子繞組的接紅方式來改變籠型電動機(jī)定子極對數(shù)達(dá)到調(diào)速目的，特點如下：</p><p>

6、;　　1、具有較硬的機(jī)械特性，穩(wěn)定性良好；</p><p>　　2、無轉(zhuǎn)差損耗，效率高；</p><p>　　3、接線簡單、控制方便、價格低；</p><p>　　4、有級調(diào)速，級差較大，不能獲得平滑調(diào)速；</p><p>　　5、可以與調(diào)壓調(diào)速、電磁轉(zhuǎn)差離合器配合使用，獲得較高效率的平滑調(diào)速特性。</p><p>　

7、　本方法適用于不需要無級調(diào)速的生產(chǎn)機(jī)械，如金屬切削機(jī)床、升降機(jī)、起重設(shè)備、風(fēng)機(jī)、水泵等。</p><p><b>　　二、變頻調(diào)速方法</b></p><p>　　變頻調(diào)速是改變電動機(jī)定子電源的頻率，從而改變其同步轉(zhuǎn)速的調(diào)速方法。變頻調(diào)速系統(tǒng)主要設(shè)備是提供變頻電源的變頻器，變頻器可分成交流－直流－交流變頻器和交流－交流變頻器兩大類，目前國內(nèi)大都使用交－直－交變頻器。其

8、特點：</p><p>　　1、效率高，調(diào)速過程中沒有附加損耗</p><p>　　2、應(yīng)用范圍廣，可用于籠型異步電動機(jī)</p><p>　　3、調(diào)速范圍大，特性硬，精度高</p><p>　　4、技術(shù)復(fù)雜，造價高，維護(hù)檢修困難。</p><p>　　本方法適用于要求精度高、調(diào)速性能較好場合。</p>&

9、lt;p><b>　　三、串級調(diào)速方法</b></p><p>　　串級調(diào)速是指繞線式電動機(jī)轉(zhuǎn)子回路中串入可調(diào)節(jié)的附加電勢來改變電動機(jī)的轉(zhuǎn)差，達(dá)到調(diào)速的目的。大部分轉(zhuǎn)差功率被串入的附加電勢所吸收，再利用產(chǎn)生附加的裝置，把吸收的轉(zhuǎn)差功率返回電網(wǎng)或轉(zhuǎn)換能量加以利用。根據(jù)轉(zhuǎn)差功率吸收利用方式，串級調(diào)速可分為電機(jī)串級調(diào)速、機(jī)械串級調(diào)速及晶閘管串級調(diào)速形式，多采用晶閘管串級調(diào)速，其特點為：<

10、;/p><p>　　1、可將調(diào)速過程中的轉(zhuǎn)差損耗回饋到電網(wǎng)或生產(chǎn)機(jī)械上，效率較高；</p><p>　　2、裝置容量與調(diào)速范圍成正比，投資省，適用于調(diào)速范圍在額定轉(zhuǎn)速７０％－９０％的生產(chǎn)機(jī)械上；</p><p>　　3、調(diào)速裝置故障時可以切換至全速運(yùn)行，避免停產(chǎn)；</p><p>　　4、晶閘管串級調(diào)速功率因數(shù)偏低，諧波影響較大；</p&g

11、t;<p>　　本方法適合于風(fēng)機(jī)、水泵及軋鋼機(jī)、礦井提升機(jī)、擠壓機(jī)上使用。</p><p>　　四、繞線式電動機(jī)轉(zhuǎn)子串電阻調(diào)速方法</p><p>　　繞線式異步電動機(jī)轉(zhuǎn)子串入附加電阻，使電動機(jī)的轉(zhuǎn)差率加大，電動機(jī)在較低的轉(zhuǎn)速下運(yùn)行。串入的電阻越大，電動機(jī)的轉(zhuǎn)速越低。此方法設(shè)備簡單，控制方便，但轉(zhuǎn)差功率以發(fā)熱的形式消耗在電阻上。屬有級調(diào)速，機(jī)械特性較軟。</p>

12、<p>　　五、定子調(diào)壓調(diào)速方法</p><p>　　當(dāng)改變電動機(jī)的定子電壓時，可以得到一組不同的機(jī)械特性曲線，從而獲得不同轉(zhuǎn)速。由于電動機(jī)的轉(zhuǎn)矩與電壓平方成正比，因此最大轉(zhuǎn)矩下降很多，其調(diào)速范圍較小，使一般籠型電動機(jī)難以應(yīng)用。為了擴(kuò)大調(diào)速范圍，調(diào)壓調(diào)速應(yīng)采用轉(zhuǎn)子電阻值大的籠型電動機(jī)，如專供調(diào)壓調(diào)速用的力矩電動機(jī)，或者在繞線式電動機(jī)上串聯(lián)頻敏電阻。為了擴(kuò)大穩(wěn)定運(yùn)行范圍，當(dāng)調(diào)速在2：1以上的場合應(yīng)采用反

13、饋控制以達(dá)到自動調(diào)節(jié)轉(zhuǎn)速目的。</p><p>　　調(diào)壓調(diào)速的主要裝置是一個能提供電壓變化的電源，目前常用的調(diào)壓方式有串聯(lián)飽和電抗器、自耦變壓器以及晶閘管調(diào)壓等幾種。晶閘管調(diào)壓方式為最佳。調(diào)壓調(diào)速的特點：</p><p>　　1、調(diào)壓調(diào)速線路簡單，易實現(xiàn)自動控制。</p><p>　　2、調(diào)壓過程中轉(zhuǎn)差功率以發(fā)熱形式消耗在轉(zhuǎn)子電阻中，效率較低。</p>

14、<p>　　調(diào)壓調(diào)速一般適用于100KW以下的生產(chǎn)機(jī)械。</p><p>　　六、電磁調(diào)速電動機(jī)調(diào)速方法</p><p>　　電磁調(diào)速電動機(jī)由籠型電動機(jī)、電磁轉(zhuǎn)差離合器和直流勵磁電源（控制器）三部分組成。直流勵磁電源功率較小，通常由單相半波或全波晶閘管整流器組成，改變晶閘管的導(dǎo)通角，可以改變勵磁電流的大小。</p><p>　　電磁轉(zhuǎn)差離合器由電樞、磁極

15、和勵磁繞組三部分組成。電樞和后者沒有機(jī)械聯(lián)系，都能自由轉(zhuǎn)動。電樞與電動機(jī)轉(zhuǎn)子同軸聯(lián)接稱主動部分，由電動機(jī)帶動；磁極用聯(lián)軸節(jié)與負(fù)載軸對接稱從動部分。當(dāng)電樞與磁極均為靜止時，如勵磁繞組通以直流，則沿氣隙圓周表面將形成若干對N、S極性交替的磁極，其磁通經(jīng)過電樞。當(dāng)電樞隨拖動電動機(jī)旋轉(zhuǎn)時，由于電樞與磁極間相對運(yùn)動，因而使電樞感應(yīng)產(chǎn)生渦流，此渦流與磁通相互作用產(chǎn)生轉(zhuǎn)矩，帶動有磁極的轉(zhuǎn)子按同一方向旋轉(zhuǎn)，但其轉(zhuǎn)速恒低于電樞的轉(zhuǎn)速N1，這是一種轉(zhuǎn)差調(diào)速

16、方式，變動轉(zhuǎn)差離合器的直流勵磁電流，便可改變離合器的輸出轉(zhuǎn)矩和轉(zhuǎn)速。電磁調(diào)速電動機(jī)的調(diào)速特點：</p><p>　　1、裝置結(jié)構(gòu)及控制線路簡單、運(yùn)行可靠、維修方便；</p><p>　　2、調(diào)速平滑、無級調(diào)速</p><p>　　3、對電網(wǎng)無諧影響；</p><p>　　4、速度失大、效率低。</p><p>　　本方

17、法適用于中、小功率，要求平滑動、短時低速運(yùn)行的生產(chǎn)機(jī)械。</p><p>　　七、液力耦合器調(diào)速方法</p><p>　　液力耦合器是一種液力傳動裝置，一般由泵輪和渦輪組成，它們統(tǒng)稱工作輪，放在密封殼體中。殼中充入一定量的工作液體，當(dāng)泵輪在原動機(jī)帶動下旋轉(zhuǎn)時，處于其中的液體受葉片推動而旋轉(zhuǎn)，在離心力作用下沿著泵輪外環(huán)進(jìn)入渦輪時，就在同一轉(zhuǎn)向上給渦輪葉片以推力，使其帶動生產(chǎn)機(jī)械運(yùn)轉(zhuǎn)。液力耦合

18、器的動力轉(zhuǎn)輸能力與殼內(nèi)相對充液量的大小是一致的。在工作過程中，改變充液率就可以改變耦合器的渦輪轉(zhuǎn)速，作到無級調(diào)速，其特點為：</p><p>　　1、功率適應(yīng)范圍大，可滿足從幾十千瓦至數(shù)千千瓦不同功率的需要；</p><p>　　2、結(jié)構(gòu)簡單，工作可靠，使用及維修方便，且造價低；</p><p>　　3、尺寸小，能容大；</p><p>　　

19、4、控制調(diào)節(jié)方便，容易實現(xiàn)自動控制。</p><p>　　本方法適用于風(fēng)機(jī)、水泵的調(diào)速。</p><p>　　The three-phase induction motor speed control method</p><p>　　Three-phase asynchronous motor speed formula: N = 60f / p (1-s) &l

20、t;/p><p>　　Can be seen from the above formula, change the power supply frequency f, motor pole number p and the slip s may be too much to change the speed of purpose. From the speed of the essence of view, is s

21、imply a different way to change speed synchronous AC motor does not change the sync transfer speed or two.</p><p>　　Widespread use in production machines without changing the synchronous speed of motor speed

22、 control method Wound Rotor Series Resistance Speed, chopper speed control, cascade control, and application of electromagnetic slip clutch, fluid couplings, clutches and other film speed. Change the synchronous speed of

23、 change on the number of stator pole multi-speed motor to change the stator voltage and frequency to frequency conversion with no change to the motor speed and so on.</p><p>　　Energy from the speed point of

24、view when, with high speed method and inefficient methods of two kinds of speed: high speed when the slip refers to the same, so no slip losses, such as multi-speed motors, Slip frequency control and loss can speed recov

25、ery methods (such as cascade control, etc.). A deteriorating loss of speed control methods are inefficient speed, such as series resistance of the rotor speed method, the energy loss in the rotor circuit on; Electromagne

26、tic Clutch The speed method, </p><p>　　1.Variable Speed Control Method of Pole PairsThis speed is then used to change the stator winding way to change the red cage motor stator pole pairs to achieve speed c

27、ontrol purposes, the following featuresWith hard mechanical properties, good stability:</p><p>　　No slip loss, high efficiency; Wiring simple, easy to control, low price;A level speed, differential large, c

28、an not get smooth speed control;With pressure and speed adjustment, with the use of electromagnetic slip clutch, smooth and efficient access to high speed characteristics.</p><p>　　This method is suitable f

29、or the production does not require variable speed machinery, such as metal cutting machine Bed , Lift , Lifting equipment, Fans Water Pump And so on.</p><p>　　2.the Frequency Control Method</p><p&

30、gt;　　Frequency Control Method Frequency control is to change the motor stator Power supply Frequency, thus changing the speed of its synchronous speed method. Frequency control system main equipment is to provide variabl

31、e frequency power supply Inverter , Inverter can be divided into AC - DC - AC inverter and AC - AC converter two categories, most of the current domestic use of AC - DC - AC inverter. Its characteristics High efficiency,

32、 speed the process without additional loss; Wide range of ap</p><p>　　This method is suitable for the high accuracy, good speed performance occasions. </p><p>　　3. Cascade Speed Regulation

33、 Method </p><p>　　Cascade control method Cascade control is wound into the rotor circuit in the series of additional potential can be adjusted to change the motor's slip, to achieve speed control purp

34、oses. Most of the deterioration in power to be in series with the added potential absorbed, re-use generate additional devices to absorb the deterioration in power to return power to use or conversion of energy. Slip-pow

35、er absorption under way, cascade control can be divided into Motor Cascade control, mechanical and</p><p>　　4. Wound Rotor Motor Speed Control Method of Series ResistanceWound Rotor Motor additional resista

36、nce in series, so that the motor slip up, motor running at low speed. The greater the resistance in series, the motor speed is lower. This method is simple, easy to control, but deteriorate the power consumption in the f

37、orm of heat in the resistor. Is a class speed, soft mechanical properties.</p><p>　　5. the Stator Pressure and Speed Adjustment MethodStator voltage when changing the motor, you can get a different set of m

38、echanical properties of curves, which were different speeds. Since the motor torque and voltage proportional to the square, the largest decline in a lot of torque, speed range of its small cage motors in general and diff

39、icult to apply. In order to expand the speed range, pressure and speed adjustment should be larger rotor resistance value cage motors, such as dedicated volt</p><p>　　Pressure and speed adjustment is a key d

40、evice to provide power supply voltage, the current way of a tandem common saturation voltage regulator Reactor , Auto Transformer And several other Thyristor Surge. Thyristor Surge is the best way. Adjusting Speed featur

41、esPressure and speed adjustment circuit is simple, easy to realize automatic control; Poor power surge process to heat transfer in the rotor resistance in the form of consumption, low efficiency.</p><p>

42、;　　Pressure and speed adjustment generally applies to 100KW below production machinery.</p><p>　　Rlectromagnetic speed regulating motor speed control method of electromagnetic </p><p>　　Speed re

43、gulating electric motor squirrel cage motor, electric slip clutch and DC excitation power supply (Controller) consists of three parts. DC excitation power small, usually consisting of single phase half-wave or full wave

44、rectifiers thyristors composition, change thyristor conduction angle, you can change the magnetizing current size. </p><p>　　6. Electromagnetic speed regulating motor sp

45、eed control method</p><p>　　Electromagnetic slip clutch armature, poles and excitation windings composed of three parts. Armature and the latter has no mechanical contact, are free to rotate. Armature motor

46、coaxial connection active part, driven by motors; docking with the load axis magnetic pole coupling from the moving parts. When the armature poles are at rest, such as excitation windings for DC, along the circumferentia

47、l surface will form a number of air gap on the n, s, of alternating polarity poles, the magnetic flux</p><p>　　Appliances, structure and control circuit is simple, reliable operation, easy maintenance; spee

48、d and smooth, stepless speed regulation</p><p>　　The power network harmonic effects; </p><p>　　Lost speed, low efficiency. </p><p>　　This method applies to medium and small power, r

49、equires low speed when the smooth, short run production machinery.</p><p>　　7. Hydraulic Coupler Speed Regulation Method</p><p>　　The hydraulic coupler speed regulating hydraulic Coupler is a de

50、vice for hydraulic drive, is made up of the pump and turbine, they collectively work wheels, placed in a sealed case. Shell filled with a certain amount of working fluid, when pump is impulse driven by rotation, in which

51、 liquid propelled by blades which rotate, and under the action of centrifugal force along the outer wheels when entering the turbine pump, to thrust to the turbine blades on the same turn, make it drive production ma<

52、/p><p>　　Power scope, can meet the needs of from a couple of different power 10-kilowatt to shuqianqian; </p><p>　　Simple structure, reliable performance, easy to operation and maintenance, and low