外文翻譯--pwm整流器中的應(yīng)用自反饋串級(jí)調(diào)速系統(tǒng)

1、<p><b>　　畢業(yè)論文（設(shè)計(jì)）</b></p><p><b>　　外文翻譯</b></p><p>　　題 目：PWM整流器中的應(yīng)用自反饋串級(jí)調(diào)速系統(tǒng)</p><p>　　系部名稱： 專業(yè)班級(jí)： </p><p>　　學(xué)生姓名：

2、 學(xué) 號(hào)： </p><p>　　指導(dǎo)教師： 教師職稱： </p><p><b>　　20 年月日</b></p><p>　　PWM整流器在自反饋串級(jí)調(diào)速系統(tǒng)的應(yīng)用</p><p><b>　　摘要：</

3、b></p><p>　　本文分析了自反饋串級(jí)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(jí)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(wú)功功率去補(bǔ)償傳統(tǒng)的串級(jí)調(diào)速系統(tǒng)產(chǎn)生的感應(yīng)無(wú)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)。</p><p>　　索

4、引詞 - 串級(jí)控制，功率因數(shù)，脈寬調(diào)制</p><p><b>　　一 導(dǎo)言</b></p><p>　　在我們的日常生活和工業(yè)生產(chǎn)中，電力系統(tǒng)占相當(dāng)大的比重，特別是這些載荷鼓風(fēng)機(jī)和泵，使用多能量，因此節(jié)能的風(fēng)機(jī)和水泵正在成為工業(yè)生產(chǎn)的主要問(wèn)題之一。利用可控硅串級(jí)調(diào)速控制，是風(fēng)機(jī)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20％

5、?40％。但是，傳統(tǒng)的級(jí)聯(lián)速度控制系統(tǒng)具有低諧波因素和多一些缺點(diǎn)。功率因數(shù)高負(fù)荷，高速低轉(zhuǎn)速負(fù)荷0.4 0.6。它帶來(lái)了巨大的浪費(fèi)和污染。這個(gè)缺點(diǎn)阻礙了延伸和串級(jí)調(diào)速中的應(yīng)用。在一種新的級(jí)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(jì)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)。</p><p>　　二 CHOP內(nèi)饋調(diào)速的原理</p><p>　　在電機(jī)中內(nèi)反饋串級(jí)調(diào)

6、速控制系統(tǒng)是異步電動(dòng)機(jī)轉(zhuǎn)子系列woundrotor抵抗速度的基礎(chǔ)。一個(gè)新的三相對(duì)稱繞組命名調(diào)整繞組定子繞組上，建立的初級(jí)繞組稱為主繞組。額外的電動(dòng)勢(shì)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(dòng)勢(shì)serriedwound與轉(zhuǎn)子繞組，其速度可以通過(guò)改變其規(guī)定。普通串級(jí)調(diào)速系統(tǒng)調(diào)速是通過(guò)改變反角β，但無(wú)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(jí)speedregulation系統(tǒng)如下：</p><p&g

7、t;　　1.對(duì)斬波串級(jí)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(shí)間比和對(duì)應(yīng)的是轉(zhuǎn)子額定電壓。因此，電機(jī)的旋轉(zhuǎn)速度可通過(guò)調(diào)節(jié)控制脈沖寬度的比例。</p><p><b>　?。?）</b></p><p><b>　　三 功率因數(shù)的分析</b></p&

8、gt;<p>　　對(duì)串級(jí)調(diào)速系統(tǒng)功率因數(shù)為：在公式中，P1是由電機(jī)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(jī)從電網(wǎng)吸收的無(wú)功功率; QT是逆變器從電網(wǎng)吸收的無(wú)功功率。在斬波串級(jí)調(diào)速系統(tǒng)，逆角β為固定的，因?yàn)椋且话慵s 。因此，在系統(tǒng)中QT是不變的。但是，當(dāng)電機(jī)在低速運(yùn)行，增加，功率因數(shù)下降。</p><p>　　四 PWM整流器的定性分析</p><p>

9、　　可控硅由PWM整流器 取代，新的級(jí)聯(lián)速度控制系統(tǒng)方案原理圖圖2：</p><p>　　PWM整流器是一個(gè)四象限變流器。其交流和直流側(cè)可以控制的。當(dāng)使用電網(wǎng)電測(cè)力矢量為參考，則PWM整流器的工作fourquadrant可以通過(guò)控制交流側(cè)電壓向量V。是固定的，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(yùn)動(dòng)軌跡是一個(gè)圓的半徑的VL。當(dāng)V的電壓矢量端點(diǎn)的圓軌跡A點(diǎn)，電流矢量延遲電動(dòng)勢(shì)矢量 。PWM整

10、流器網(wǎng)側(cè)電感為圖3顯示的特征。當(dāng)V的電壓矢量端點(diǎn)的圓軌跡B點(diǎn)，電流矢量I是平行，與電動(dòng)勢(shì)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(dāng)電壓矢量端點(diǎn)的圓V位點(diǎn)C點(diǎn)，電流矢量I是電動(dòng)勢(shì)矢量的PWM整流器網(wǎng)側(cè)電容，圖5顯示的特征。當(dāng)V的電壓矢量端點(diǎn)的圓軌跡D點(diǎn)，電流矢量I是平行，與電動(dòng)勢(shì)矢量E相反的方向。在PWM整流器網(wǎng)側(cè)顯示為圖6負(fù)阻特性。 </p><p>　　（圖3）

11、 (圖4) </p><p>　　（圖5） （圖6）</p><p>　　所以一定要確保輸出端的直流電壓，輸入電流和交流側(cè)電壓可以 在負(fù)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)。</p><p>　　五 PWM整流器控制系統(tǒng)的設(shè)計(jì)</p><p>　　三

12、相PWM整流器交流側(cè)均為時(shí)變交流量，不利于控制系統(tǒng)設(shè)計(jì)。引進(jìn)電機(jī)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(gè)交流電機(jī)的模型與三相逆變器相同, 我們更可以把三相交流電機(jī)的控制理論運(yùn)用到三相PWM整流器中。把三相靜止坐標(biāo)變換成二相旋轉(zhuǎn)坐標(biāo)，在進(jìn)行解耦控制，電壓為外環(huán)，電壓給定和實(shí)際的差值進(jìn)行調(diào)節(jié)后經(jīng)過(guò)PI后得到有功電流的給定，設(shè)定想要給定的無(wú)功電流，高功率因數(shù)系統(tǒng)中，功率因數(shù)為1，所以無(wú)功電流給定為0，在通過(guò)檢測(cè)出來(lái)的實(shí)際的電流

13、矢量變換和解耦后得到的實(shí)際的有功電流和無(wú)功電流與給定的有功電流和無(wú)功電流的比較來(lái)得到指令電壓信號(hào)，從而我們得到如圖所示的控制框圖來(lái)實(shí)現(xiàn)系統(tǒng)的控制。這種直接通過(guò)檢測(cè)實(shí)際電流，再進(jìn)行矢量變換解耦控制的方法直接對(duì)電流進(jìn)行控制和上述的通過(guò)電壓的關(guān)系來(lái)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(biāo)變換的關(guān)系，三相PWM整流器拓?fù)浣Y(jié)構(gòu)的兩相旋轉(zhuǎn)坐標(biāo)系dq模型可描述為：</p><p><b>　　?（2）&

14、lt;/b></p><p>　　上述方程中，，是d和q軸的電動(dòng)勢(shì)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。</p><p>　　在公式（2），因?yàn)镈和q軸分量耦合，很難設(shè)計(jì)出控制系統(tǒng)。因此，一個(gè)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：</p><p>&

15、lt;b>　?。?）</b></p><p>　　，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(jià)于，。</p><p>　　在電壓環(huán)，所需的電流是三相對(duì)稱正弦電流，它的電網(wǎng)電壓同頻。因此，在同步旋轉(zhuǎn)坐標(biāo)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）。</p><p><b>　?。?）</b>

16、</p><p>　　介紹了在dq概念的瞬時(shí)功率，同步旋轉(zhuǎn)坐標(biāo)系，瞬時(shí)有功功率和PWM整流器無(wú)功功率可以顯示為（5）：</p><p><b>　　(5)</b></p><p>　　為了補(bǔ)償 電機(jī)吸收無(wú)功功率 ，PWM整流器工程電容性質(zhì)。因此，編號(hào)是：</p><p><b>　　(6)</b>&

17、lt;/p><p>　　表格方程（3）（4）（6），對(duì)PWM整流器控制框圖圖7：</p><p><b>　　(圖7)</b></p><p>　　六 PWM整流器串級(jí)調(diào)速系統(tǒng)的仿真結(jié)果</p><p>　　PWM整流器仿真串級(jí)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(jī)額定功率為710kW，定子額定電

18、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。</p><p><b>　?。▓D8）</b></p><p><b>　　（圖9）</b></p><p><b>　?。?/p>

19、圖10）</b></p><p>　　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(yùn)行。因此，有源電力輸送到電網(wǎng)，同時(shí)產(chǎn)生的容性無(wú)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。</p><p>　　在傳統(tǒng)的斬波串級(jí)調(diào)速系統(tǒng)，因?yàn)榫чl管半控裝置，逆變器上運(yùn)行的特點(diǎn)和電感電流的波形

20、不是正弦波。因此網(wǎng)側(cè)電流延遲和系統(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。</p><p>　　除了新的串級(jí)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(duì)傳統(tǒng)的斬波串級(jí)調(diào)速系統(tǒng)，以12.28％的一半。</p><p><b>　　（圖11）</b></p><p><b&g

21、t;　　（圖12）</b></p><p><b>　?。▓D13）|</b></p><p><b>　　（圖14）</b></p><p><b>　　七 結(jié)論</b></p><p>　　本文提出了一種新的以級(jí)聯(lián)速度控制系統(tǒng)為基礎(chǔ)的PWM整流器。仿真驗(yàn)證了新的控

22、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(jí)調(diào)速系統(tǒng)相比，新的串級(jí)調(diào)速控制系統(tǒng)可節(jié)省無(wú)功補(bǔ)償裝置，降低諧波。因此，PWM整流器串級(jí)調(diào)速系統(tǒng)將廣泛應(yīng)用于未來(lái)。</p><p><b>　　八 參考文獻(xiàn)</b></p><p>　　[1]馬里烏什馬林諾夫斯基，馬立克Jasin'ski，“簡(jiǎn)單的三相PWM整流器直接功率控制采用空間矢量調(diào)制（DPC的支持向量

23、機(jī)），工業(yè)電子，第一卷電機(jī)及電子學(xué)工程師聯(lián)合會(huì)交易，51，2號(hào)，2004年4月。</p><p>　　[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(jí)聯(lián)調(diào)速系統(tǒng)”，電力電子，第39卷第6號(hào)，2005年12月。 </p><p>　　[3]章充維，張星，“PWM整流器及其控制策略”，北京：中國(guó)機(jī)械工業(yè)出版社，2003。 </p><p>　　[4]陳白石“

24、電力拖動(dòng)自動(dòng)控制系統(tǒng)”，北京：中國(guó)機(jī)械工業(yè)出版社，1997年論文 </p><p>　　[5]宋桂英，“內(nèi)反饋調(diào)速電機(jī)系統(tǒng)”，碩士論文，河北科技大學(xué)。</p><p><b>　　九 履歷</b></p><p>　　馬暢瀟出生在1982年9月18日的中國(guó)。他于2005年加入中國(guó)北方電力大學(xué)?，F(xiàn)在，他正在攻讀電氣和電子工程學(xué)院學(xué)士學(xué)位和他的專業(yè)

25、是電力電子及電氣傳動(dòng)設(shè)備。電子郵箱：machangxiao@sohu.com</p><p>　　汪埃甍于1963年出生在中國(guó)。她是一名華中電力大學(xué)的副教授。是美國(guó)威斯康星大學(xué)麥迪遜分校學(xué)者從2006年1月至Jun.2007。電子郵箱：aiming_068@163.com</p><p>　　本文摘譯自：R.Pena.J.C.Ctare.GM.Asher.Doubly fed induct

26、ion generator using back-to back PWM converters and its application to variable-spced wind energy cration.IEEEProc-Electr.PowerAppl.Vol.143.NO.3.May1996:231-241</p><p>　　The Application of PWM Rectifier Used

27、 in SelfFeedback </p><p>　　Cascade Speed Control System</p><p>　　Ma Changxiao and Wang Aimeng</p><p>　　Abstract--Analyzed the reason that the power factor of self feedback cascade s

28、peed control system is poor. A new cascaded speed-adjusting system scheme based on PWM technique is proposed in this paper. SCR is substituted with IGBT in the system. It can provide capacitive reactive power to compensa

29、te inductive reactive power which the conventional cascaded speed adjusting system produces. So it can improve power factor. PWM rectifier and PWM direct current control strategy are introduced in the p</p><p&

30、gt;　　Index Terms-- Cascade control, power factor, PWM</p><p>　　I. INTRODUCTION</p><p>　　IN our daily life and industrial production, electric drive accounts for a large proportion，especially the

31、se 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 ene

32、rgy conservation of fans and pumps. Compare with frequency control of motor speed, this method is better and cheaper, and not only bring about smooth speed regulating but als</p><p>　　II. PRINCIPLE OF CHOP I

33、NNER FEEDBACK SPEED REGULATION</p><p>　　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-pha

34、se symmetrical winding named 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 win

35、ding. Using thyristor inverter, the additional electromotive force is serriedwound with rotor winding, and the sp</p><p><b>　　is Fig.1.</b></p><p><b>　　Fig.1</b></p>

36、;<p>　　Fig. 1. Structure of chopping cascade speed regulation system</p><p>　　Output voltage of the rectifier bridge is .</p><p>　　Output voltage of the inverter is ?.</p><p>

37、;　　Equation of the rotor loop is </p><p>　　So the formula of the rotation speed can shows as:</p><p>　　UT 2 is the phase voltage of the adjusting winding, ??is the pulse duration ratio of the c

38、hopper and E20 is rotor rated voltage. So the rotation speed of the motor can be controlled by regulating the pulse duration ratio.</p><p>　　III. ANALYSE OF POWER FACTOR</p><p>　　The power facto

39、r of cascade speed control system is:(1)</p><p>　　In the equation, P1 is the active power absorbed from grid by motor；PT is the active power feedback to grid form the system; Q1 is the inductive reactive pow

40、er 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 inverse angle βis fixed, because of the margin, it is gener

41、ally about 300. So QT is changeless in the system. But when the motor runs at a low speed, PT increased, and the power fact</p><p>　　IV. ANALYSE OF PWM RECTIFIER</p><p>　　Substituted SCR by PWM

42、rectifier, the principle diagram of the new cascaded speed control system scheme is Fig.2.</p><p>　　The Application of PWM Rectifier Used in Self- Feedback Cascade Speed Control System Ma Changxiao and Wang

43、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 using the grid electromotive force vector as reference, th

44、e 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 trajec</p><p>　　characteristic as Fig.4.

45、 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 rectifier shows capacitance characteristic as Fig.5. When the endpoint o

46、f 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 Fi

47、g.6.</p><p>　?。?） （4）</p><p>　　（5） （6）</p><p>　　So make sure the output voltage of the DC side isinvariableness, the input current

48、and voltage of the AC side can work on negative resistance or capacitance characteristic, hence QT =0or QT=?Q1 . The power factor is increased.</p><p>　　V. DESIGN OF THE PWM RECTIFIER CONTROL SYSTEM</p>

49、;<p>　　As the AC side of three-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 change

50、s to d-q synchronously rotating reference frame bases on the grid voltage frequency. So the sinusoidal variables in ABC reference frame become DC variables in d-q synchronously rotating reference frame. It is easy to des

51、ign the control system. In the d-q synchronously rotating reference frame,</p><p><b>　?。?）</b></p><p>　　In the equation mentioned above, ed ,eq is the d and q axis component of the e

52、lectromotive 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

53、 the equation (2), because the d and q axis 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 </p><p&

54、gt;<b>　　(3)</b></p><p>　　KiP,KiI is the proportion adjustment coefficient and the integral regulation coefficient of the current regulating loop. *, * iq id is the appointed value of iq ,id . In

55、the voltage loop, the needed current is the three phase symmetrical sine current, and it’s the same frequency of grid voltage. So in d-q synchronously rotating reference frame,and are DC quantity. Hence iq and id can be

56、adjusted smoothly by PI regulator. The equation is (4).</p><p><b>　　?(4)</b></p><p>　　Introduced the conception of instantaneous power, in the dq synchronously rotating reference fra

57、me, the instantaneous active power and reactive power of the PWM rectifier net side can shows as （5）:</p><p><b>　　(5)</b></p><p>　　In order to compensate the inductive reactive power

58、 absorbed by motor, the PWM rectifier works in capacitive character. So id is:</p><p><b>　　(6)</b></p><p>　　Form the equation (3) (4) (6), the control block diagram of PWM rectifier

59、is Fig.7.</p><p>　　VI. SIMULATION RESULTS OF THE PWM RECTIFIER CASCADE</p><p>　　SPEED CONTROL SYSTEM</p><p>　　Simulate the PWM rectifier cascade speed control system base on the str

60、ucture 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 o

61、f adjusting winding is 510V, the 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</p>

62、<p><b>　　Fig.8</b></p><p><b>　　Fig.9</b></p><p><b>　　Fig.10</b></p><p>　　From Fig.8, the DC voltage works on 1200V, it is beneficial to reg

63、ulate the speed smoothly. Fig.9 is 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 ca

64、pacitive reactive power. Hence the system works on unity power factor, as the waveform of voltage and current in Fig.10.</p><p>　　In conventional chopping cascade speed regulation system, because thyristor i

65、s 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 vol

66、tage of thyristor-inverter and grid is shown in Fig.11 and Fig.12</p><p><b>　　Fig.11</b></p><p><b>　　Fig.12</b></p><p>　　Besides the new cascade speed contro

67、l 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 regulation system which is 12.28%.</p&

68、gt;<p><b>　　Fig.13</b></p><p><b>　　Fig.14</b></p><p>　　VII. CONCLUSION</p><p>　　This paper proposed a new cascaded speed control system scheme based o

69、n 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 c

70、ontrol system saves reactive power compensation device and decreases harmonic. So the PWM rectifier cascade speed regulation system will be applied widely in the future.</p><p>　　VIII. REFERENCES</p>

71、<p>　　Periodicals:</p><p>　　[1] Mariusz Malinowski, and Marek Jasin’ski, "Simple Direct Power Control of Three-Phase PWM Rectifier Using Space-Vector Modulation (DPC-SVM)," IEEE TRANSACTION ON

72、 INDUSTRIAL ELECTRONICS, vol. 51, NO.2, Apr. 2004.</p><p>　　[2] Jiang Youhua, Ning Yu, and Gong Youmin, "Research on Unity Power Factor Inner-feed Chopper Cascaded Speed-adjusting System," Power El

73、ectronics, vol.39, NO.6, December, 2005. Books:</p><p>　　[3] Zhang Chongwei and Zhang Xing, "PWM Rectifier and Control Strategy," Beijing: China Machine Press, 2003.</p><p>　　[4] Chen

74、Baishi, "Electricity Pull Automation Control System," Beijing: China Machine Press, 1997 Dissertations:</p><p>　　[5] Song Guiying, "Internal Feed-back Motor and Speed Regulation System,"

75、Master degree dissertation, Hebei University of Technology.IX. BIOGRAPHIES Ma Changxiao was born in China on Sep. 18, 1982. He joined the North China Electric Power University in 2005. Now he is pursuing his master’s deg