外文翻譯 PWM整流器中的應(yīng)用自反饋串級調(diào)速系統(tǒng)

1、畢業(yè)論文（設(shè)計）外文翻譯題 目：PWM整流器中的應(yīng)用自反饋串級調(diào)速系統(tǒng)系部名稱： 專業(yè)班級： 學生姓名： 學 號： 指導教師： 教師職稱： 20 年月日PWM整流器在自反饋串級調(diào)速系統(tǒng)的應(yīng)用摘要： 本文分析了自反饋串級調(diào)速系統(tǒng)功率因數(shù)較低的原因，并提出了一種新的基于PWM技術(shù)的串級調(diào)速系統(tǒng)方案。在此系統(tǒng)中，用IGBT代替了可控硅。它可以提供電容式無功功率去補償傳統(tǒng)的串級調(diào)速系統(tǒng)產(chǎn)生的感應(yīng)無功功率，因此，它可以提高功率因數(shù)。 文中介紹了PWM整流器和PWM電流控制方案。最后給出了仿真結(jié)果和結(jié)論，結(jié)果表明，新系統(tǒng)工作在單位功率因數(shù)。索引詞 - 串級控制，功率因數(shù)，脈寬調(diào)制一 導言 在我們的日常生活

2、和工業(yè)生產(chǎn)中，電力系統(tǒng)占相當大的比重，特別是這些載荷鼓風機和泵，使用多能量，因此節(jié)能的風機和水泵正在成為工業(yè)生產(chǎn)的主要問題之一。利用可控硅串級調(diào)速控制，是風機和水泵節(jié)能的有效手段。比較變頻調(diào)速控制，這種方法更好，更便宜，不僅能平滑調(diào)速還能節(jié)能2040。但是，傳統(tǒng)的級聯(lián)速度控制系統(tǒng)具有低諧波因素和多一些缺點。功率因數(shù)高負荷，高速低轉(zhuǎn)速負荷0.4 0.6。它帶來了巨大的浪費和污染。這個缺點阻礙了延伸和串級調(diào)速中的應(yīng)用。在一種新的級聯(lián)速度控制系統(tǒng)方案的基礎(chǔ)上，提出了PWM整流器。在新的計劃中，晶閘管逆變器被IGBT代帶，并且系統(tǒng)具有高功率因數(shù)。二 CHOP內(nèi)饋調(diào)速的原理 在電機中內(nèi)反饋串級調(diào)速控制系

3、統(tǒng)是異步電動機轉(zhuǎn)子系列woundrotor抵抗速度的基礎(chǔ)。一個新的三相對稱繞組命名調(diào)整繞組定子繞組上，建立的初級繞組稱為主繞組。額外的電動勢繞組的調(diào)整是由主繞組引起的。采用晶閘管逆變器，附加電動勢serriedwound與轉(zhuǎn)子繞組，其速度可以通過改變其規(guī)定。普通串級調(diào)速系統(tǒng)調(diào)速是通過改變反角，但無功功率提升，功率因數(shù)作為反角增加而減少。因此，斬波串級speedregulation系統(tǒng)如下： 1.對斬波串級調(diào)速系統(tǒng)中的整流橋輸出電壓 。逆變器的輸出電壓 轉(zhuǎn)子回路方程是。因此，旋轉(zhuǎn)速度公式可以顯示為： 是調(diào)整相繞組電壓，是斬波器脈沖持續(xù)時間比和對應(yīng)的是轉(zhuǎn)子額定電壓。因此，電機的旋轉(zhuǎn)速度可通過調(diào)節(jié)控

4、制脈沖寬度的比例。 （1）三 功率因數(shù)的分析 對串級調(diào)速系統(tǒng)功率因數(shù)為：在公式中，P1是由電機吸收的有功功率; PT是有功功率給電網(wǎng)的反饋; Q1是由電機從電網(wǎng)吸收的無功功率; QT是逆變器從電網(wǎng)吸收的無功功率。在斬波串級調(diào)速系統(tǒng)，逆角為固定的，因為，它是一般約 。因此，在系統(tǒng)中QT是不變的。但是，當電機在低速運行，增加，功率因數(shù)下降。四 PWM整流器的定性分析可控硅由PWM整流器 取代，新的級聯(lián)速度控制系統(tǒng)方案原理圖圖2： PWM整流器是一個四象限變流器。其交流和直流側(cè)可以控制的。當使用電網(wǎng)電測力矢量為參考，則PWM整流器的工作fourquadrant可以通過控制交流側(cè)電壓向量V。是固定的，

5、所以也是固定的。在這種情況下，在PWM整流器交流側(cè)電壓矢量的運動軌跡是一個圓的半徑的VL。當V的電壓矢量端點的圓軌跡A點，電流矢量延遲電動勢矢量 。PWM整流器網(wǎng)側(cè)電感為圖3顯示的特征。當V的電壓矢量端點的圓軌跡B點，電流矢量I是平行，與電動勢矢量E同一方向。在PWM整流器網(wǎng)側(cè)圖4顯示為阻力特性。當電壓矢量端點的圓V位點C點，電流矢量I是電動勢矢量的PWM整流器網(wǎng)側(cè)電容，圖5顯示的特征。當V的電壓矢量端點的圓軌跡D點，電流矢量I是平行，與電動勢矢量E相反的方向。在PWM整流器網(wǎng)側(cè)顯示為圖6負阻特性。 （圖3） (圖4) （圖5） （圖6） 所以一定要確保輸出端的直流電壓，輸入電流和交流側(cè)電壓可

6、以 在負阻或電容特性恒定的情況下工作，因此或可以提高功率因數(shù)。五 PWM整流器控制系統(tǒng)的設(shè)計三相PWM整流器交流側(cè)均為時變交流量，不利于控制系統(tǒng)設(shè)計。引進電機矢量控制的思想，從交流側(cè)看可以把電感電阻和交流側(cè)看成一個交流電機的模型與三相逆變器相同, 我們更可以把三相交流電機的控制理論運用到三相PWM整流器中。把三相靜止坐標變換成二相旋轉(zhuǎn)坐標，在進行解耦控制，電壓為外環(huán)，電壓給定和實際的差值進行調(diào)節(jié)后經(jīng)過PI后得到有功電流的給定，設(shè)定想要給定的無功電流，高功率因數(shù)系統(tǒng)中，功率因數(shù)為1，所以無功電流給定為0，在通過檢測出來的實際的電流矢量變換和解耦后得到的實際的有功電流和無功電流與給定的有功電流和無

7、功電流的比較來得到指令電壓信號，從而我們得到如圖所示的控制框圖來實現(xiàn)系統(tǒng)的控制。這種直接通過檢測實際電流，再進行矢量變換解耦控制的方法直接對電流進行控制和上述的通過電壓的關(guān)系來間接控制電流的方法更客觀，而且控制更有效。因此根據(jù)坐標變換的關(guān)系，三相PWM整流器拓撲結(jié)構(gòu)的兩相旋轉(zhuǎn)坐標系dq模型可描述為： （2） 上述方程中，是d和q軸的電動勢矢量，矢量,是組件d和q軸的在AC端，電壓矢量分量，是在交流側(cè)電流向量d和q軸分量，p為微分算子。 在公式（2），因為D和q軸分量耦合，很難設(shè)計出控制系統(tǒng)。因此，一個控制策略的前饋解耦是給出的。 PI調(diào)節(jié)器，是層狀的電流調(diào)節(jié)器，所以控制方程，矢量量化為： （3

8、） ，是比例調(diào)節(jié)系數(shù)和積分調(diào)節(jié)回路的電流調(diào)節(jié)系數(shù)。 ，等價于，。 在電壓環(huán)，所需的電流是三相對稱正弦電流，它的電網(wǎng)電壓同頻。因此，在同步旋轉(zhuǎn)坐標系 中，是DC數(shù)量。因此，和可以順利地調(diào)整PI調(diào)節(jié)器。方程式（4）。 （4） 介紹了在dq概念的瞬時功率，同步旋轉(zhuǎn)坐標系，瞬時有功功率和PWM整流器無功功率可以顯示為（5）： (5) 為了補償 電機吸收無功功率 ，PWM整流器工程電容性質(zhì)。因此，編號是： (6) 表格方程（3）（4）（6），對PWM整流器控制框圖圖7： (圖7)六 PWM整流器串級調(diào)速系統(tǒng)的仿真結(jié)果 PWM整流器仿真串級調(diào)速控制的結(jié)構(gòu)圖和圖7的直接電流控制策略系統(tǒng)的基礎(chǔ)。模擬參數(shù)是電機

9、額定功率為710kW，定子額定電壓為6000V，額定電流為72A條，調(diào)整電壓為510V，額定轉(zhuǎn)速1487r/min。交流側(cè)電感為0.001H，直流側(cè)為0.0033F電容，直流電壓為1200V的。仿真結(jié)果圖8，圖9和圖10。 （圖8） （圖9） （圖10） 從圖8可以看出直流電壓為1200V，它有利于順利調(diào)節(jié)速度。圖9為A相電壓和PWM整流器交流側(cè)電流。結(jié)果表明，PWM整流器的電容特性運行。因此，有源電力輸送到電網(wǎng)，同時產(chǎn)生的容性無功功率。因此，系統(tǒng)的工作原理功率因數(shù)，電壓波形和電流如圖10。在傳統(tǒng)的斬波串級調(diào)速系統(tǒng)，因為晶閘管半控裝置，逆變器上運行的特點和電感電流的波形不是正弦波。因此網(wǎng)側(cè)電流

10、延遲和系統(tǒng)的功率因數(shù)。電流和電壓 晶閘管逆變器并網(wǎng)如圖11圖12所示。除了新的串級調(diào)速控制系統(tǒng)具有諧波少得多。從圖13和圖14，總諧波失真的新系統(tǒng)（THD）是5.56，是對傳統(tǒng)的斬波串級調(diào)速系統(tǒng)，以12.28的一半。 （圖11） （圖12） （圖13）| （圖14）七 結(jié)論 本文提出了一種新的以級聯(lián)速度控制系統(tǒng)為基礎(chǔ)的PWM整流器。仿真驗證了新的控制系統(tǒng)，新系統(tǒng)可以工作在單位功率因數(shù)。與傳統(tǒng)的斬波串級調(diào)速系統(tǒng)相比，新的串級調(diào)速控制系統(tǒng)可節(jié)省無功補償裝置，降低諧波。因此，PWM整流器串級調(diào)速系統(tǒng)將廣泛應(yīng)用于未來。八 參考文獻1馬里烏什馬林諾夫斯基，馬立克Jasin'ski，“簡單的三相P

11、WM整流器直接功率控制采用空間矢量調(diào)制（DPC的支持向量機），工業(yè)電子，第一卷電機及電子學工程師聯(lián)合會交易，51，2號，2004年4月。2蔣優(yōu)化，寧宇，和龔優(yōu)岷，“研究單位功率因數(shù)的內(nèi)饋斬波級聯(lián)調(diào)速系統(tǒng)”，電力電子，第39卷第6號，2005年12月。 3章充維，張星，“PWM整流器及其控制策略”，北京：中國機械工業(yè)出版社，2003。 4陳白石“電力拖動自動控制系統(tǒng)”，北京：中國機械工業(yè)出版社，1997年論文 5宋桂英，“內(nèi)反饋調(diào)速電機系統(tǒng)”，碩士論文，河北科技大學。九 履歷馬暢瀟出生在1982年9月18日的中國。他于2005年加入中國北方電力大學?，F(xiàn)在，他正在攻讀電氣和電子工程學院學士學位和他

12、的專業(yè)是電力電子及電氣傳動設(shè)備。電子郵箱：machangxiao汪埃甍于1963年出生在中國。她是一名華中電力大學的副教授。是美國威斯康星大學麥迪遜分校學者從2006年1月至Jun.2007。電子郵箱：aiming_068本文摘譯自：R.Pena.J.C.Ctare.GM.Asher.Doubly fed induction generator using back-to back PWM converters and its application to variable-spced wind energy cration.IEEEProc-Electr.PowerAppl.Vol.143.

13、NO.3.May1996:231-241 The Application of PWM Rectifier Used in SelfFeedback Cascade Speed Control System Ma Changxiao and Wang Aimeng Abstract-Analyzed the reason that the power factor of self feedback cascade speed control system is poor. A new cascaded speed-adjusting system scheme based on PWM tec

14、hnique is proposed in this paper. SCR is substituted with IGBT in the system. It can provide capacitive reactive power to compensate inductive reactive power which the conventional cascaded speed adjusting system produces. So it can improve power factor. PWM rectifier and PWM direct current control

15、strategy are introduced in the paper. At last, simulation result and conclusion are given. It shows that the new system works at unity power Factor. Index Terms- Cascade control, power factor, PWMI. INTRODUCTION IN our daily life and industrial production, electric drive accounts for a large proport

16、ion，especially these loads air blowers and pumps that use much energy, so the energy saving of fans and pumps is becoming one of the main issues in industry production. The use of SCR cascade speed control is an effective means of the energy conservation of fans and pumps. Compare with frequency con

17、trol of motor speed, this method is better and cheaper, and not only bring about smooth speed regulating but also save energy 20%40%. But the conventional cascaded speed control system has some disadvantages of low factor and much harmonic. The power factor is 0.6 with high-speed load and 0.4 with l

18、ow-speed load. It brings great waste and pollution to the power. This disadvantage obstructs the extension and application of cascade speed regulation. A new cascaded speed control system scheme based on PWM rectifier is proposed in this paper. In the new scheme, thyristor inverter is substituted wi

19、th IGBT, and the system works with high power factor.II. PRINCIPLE OF CHOP INNER FEEDBACK SPEED REGULATION Cascade speed control system with internal feedback is base on the theory of rotor series resistance speed of woundrotor induction motor. In the motor, a new three-phase symmetrical winding nam

20、ed adjusting winding is founded on the stator winding and the primary winding called main winding. The additional electromotive force is provided by adjusting winding which induced from main winding. Using thyristor inverter, the additional electromotive force is serriedwound with rotor winding, and

21、 the speed can be regulated by changing it. The speed regulation in ordinary cascade speed control system is by changing the inverse angle , however the reactive power enhanced and the power factor decreased as the increase of inverse angle. So chopping cascade speedregulation system is proposed. Th

22、e system principle diagramis Fig.1. Fig.1 Fig. 1. Structure of chopping cascade speed regulation system Output voltage of the rectifier bridge is . Output voltage of the inverter is . Equation of the rotor loop is So the formula of the rotation speed can shows as: UT 2 is the phase voltage of the ad

23、justing winding, ô is the pulse duration ratio of the chopper and E20 is rotor rated voltage. So the rotation speed of the motor can be controlled by regulating the pulse duration ratio.III. ANALYSE OF POWER FACTOR The power factor of cascade speed control system is:(1) In the equation, P1 is t

24、he active power absorbed from grid by motor；PT is the active power feedback to grid form the system; Q1 is the inductive reactive power which is absorbed by motor from grid; QT is the inductive reactive power absorbed from grid by inverter. In the chopping cascade speed regulation system, the invers

25、e angle is fixed, because of the margin, it is generally about 300. So QT is changeless in the system. But when the motor runs at a low speed, PT increased, and the power factor decreased.IV. ANALYSE OF PWM RECTIFIER Substituted SCR by PWM rectifier, the principle diagram of the new cascaded speed c

26、ontrol system scheme is Fig.2. The Application of PWM Rectifier Used in Self- Feedback Cascade Speed Control System Ma Changxiao and Wang Aimeng Fig. 2. Structure of PWM rectifier cascade speed regulation system PWM rectifier is a four-quadrant converter. Its AC and DC sides can be controlled. When

27、using the grid electromotive force vector as reference, the PWM rectifier can work in fourquadrant by controlling the AC side voltage vector V . I hypothesis fixedness, so the is fixedness too. In this situation, the motion trajectory of the PWM rectifier AC side voltage vector is a round with the r

28、adius of VL . When the endpoint of voltage vector V on the circle locus A point, current vector I delays electromotive force vector and the net side of the PWM rectifier shows inductance characteristic as Fig.3. When the endpoint of voltage vector V on the circle locus B point, current vector I is p

29、arallel and the same direction with electromotive force vector E . The net side of the PWM rectifier shows positive resistancecharacteristic as Fig.4. When the endpoint of voltage vector V on the circle locus C point, current vector I is lead electromotive force vector and the net side of the PWM re

30、ctifier shows capacitance characteristic as Fig.5. When the endpoint of voltage vector V on the circle locus D point, current vector I is parallel and the opposite direction with electromotive force vector E . The net side of the PWM rectifier shows negative resistance characteristic as Fig.6. （3） （

31、4） （5） （6） So make sure the output voltage of the DC side isinvariableness, the input current and voltage of the AC side can work on negative resistance or capacitance characteristic, hence QT =0or QT=Q1 . The power factor is increased.V. DESIGN OF THE PWM RECTIFIER CONTROL SYSTEMAs the AC side of t

32、hree-phase PWM rectifier is timevarying, it is difficulty to design the control system. So the method of vector control of asynchronous motor is introduced. The ABC reference frame changes to d-q synchronously rotating reference frame bases on the grid voltage frequency. So the sinusoidal variables

33、in ABC reference frame become DC variables in d-q synchronously rotating reference frame. It is easy to design the control system. In the d-q synchronously rotating reference frame, the q coordinate axis is coincides with the grid electromotive force vector Edq , so the d axis component of the elect

34、romotive force vector ed is zero. In the synchronously rotating reference frame, the q axis component shows the active power and the d axis shows the reactive power. In d-q synchronously rotating reference frame, the model of three-phase PWM rectifier is: （2） In the equation mentioned above, ed ,eq

35、is the d and q axis component of the electromotive force vector Edq , vd ,vq is the d and q axis component of the voltage vector in the AC side, id ,iq is the d and q axis component of the current vector in the AC side, and p is the differential operator. In the equation (2), because the d and q axi

36、s component is coupled, it is difficult to design the control system. So a control strategy based on the feed-forward decoupling isapplied. The PI regulator is bedded in the current regulators, so the control equation of vd ,vq is: (3) KiP,KiI is the proportion adjustment coefficient and the integra

37、l regulation coefficient of the current regulating loop. *, * iq id is the appointed value of iq ,id . In the voltage loop, the needed current is the three phase symmetrical sine current, and its the same frequency of grid voltage. So in d-q synchronously rotating reference frame,and are DC quantity

38、. Hence iq and id can be adjusted smoothly by PI regulator. The equation is (4). (4)Introduced the conception of instantaneous power, in the dq synchronously rotating reference frame, the instantaneous active power and reactive power of the PWM rectifier net side can shows as （5）: (5) In order to co

39、mpensate the inductive reactive power absorbed by motor, the PWM rectifier works in capacitive character. So id is: (6) Form the equation (3) (4) (6), the control block diagram of PWM rectifier is Fig.7. VI. SIMULATION RESULTS OF THE PWM RECTIFIER CASCADE SPEED CONTROL SYSTEMSimulate the PWM rectifi

40、er cascade speed control system base on the structure of Fig.1 and the direct current control strategy of Fig.7. The simulation parameters are: the rated power of inner-feeding motor is 710kW, the stator rated voltage is 6000V, the rated current is 72A, the voltage of adjusting winding is 510V, the

41、rated speed is 1487r/min. The inductance in AC side is 0.001H, the capacitance in DC side is0.0033F, the DC voltage is 1200V. The results of simulation are Fig.8, Fig.9 and Fig.10. Fig.8 Fig.9 Fig.10 From Fig.8, the DC voltage works on 1200V, it is beneficial to regulate the speed smoothly. Fig.9 is

42、 the A phase voltage and current of PWM rectifier AC side. It shows that PWM rectifier runs on capacitance characteristic. So it transports active power to the grid meanwhile produces capacitive reactive power. Hence the system works on unity power factor, as the waveform of voltage and current in F

43、ig.10. In conventional chopping cascade speed regulation system, because thyristor is half-controlled device, the inverter runs on inductance characteristic and the current waveform is not sine wave. Hence current delays voltage in net side and the power factor of the system is poor. The current and

44、 voltage of thyristor-inverter and grid is shown in Fig.11 and Fig.12 Fig.11 Fig.12 Besides the new cascade speed control system has much less harmonic. From Fig.13 and Fig.14, the total harmonic distortion（THD）of the new system is 5.56%, it is about half of the conventional chopping cascade speed r

45、egulation system which is 12.28%. Fig.13 Fig.14VII. CONCLUSION This paper proposed a new cascaded speed control system scheme based on PWM rectifier. The simulation verified the analysis of new control system that the new system can work in unity power factor. Compared with conventional chopping cascade speed regulation system, the new cascade speed