外文翻譯--變頻技術(shù)

1、<p><b>　　附錄一</b></p><p>　　英文文獻(xiàn)：Frequency Variation Speed Control</p><p>　　1.1 The Popularity and Prospect of Frequency Variation Speed Control</p><p>　　The electric

2、al machinery exchange frequency conversion velocity modulation technology is the electricity saving, the improvement technical process improves the product quality and the improvement environment, the impetus technology

3、advancement one main method now The frequency conversion velocity modulation by its outstanding velocity modulation and the braking quality, the high efficiency, the high power factor and the electricity saving effect, t

4、he widespread applicable scope and other many me</p><p>　　In recent years exchanged in the velocity modulation most to be active, to develop quickest is the frequency conversion velocity modulation technolog

5、y, the frequency conversion velocity modulation is exchanges the velocity modulation foundation and the branch content. The last century transformer appearance causes the change voltage to become very much easy, thus has

6、 accomplished a huge electric power profession. Since long ago, the alternating current frequency always is fixed, the frequency co</p><p>　　In this recent 10 years, the frequency conversion technology appli

7、cation has the very big development in our country, and obtained the good effect to be possible to say, the frequency conversion technology has accepted for the majority users, but had no alternative but to point out, ou

8、r country in frequency conversion technology application aspect, with developed country level Shang You very big disparity. At present, the AC motors we are using now use frequency variation speed control only abou</p

9、><p>　　And with the constant development of control technique and control avenue, frequency variation speed controlled has developed the vector controlled frequency variation velocity modulation, by controlling

10、 the AC motor inside act for shunt DC motor field coper’s flux, to enhance the permanent torque output scope and static and dynamic character, make the AC motor frequency variation speed controlled system superior to DC

11、motor voltage variation speed controlled system. For simplifying the control </p><p>　　Frequency variation speed control is the best way in the motor speed modulation, it is the perfect gear in the company’s

12、 technical reform and product renewal, it is the essential composition in the industrial automatic system, it is the assumption of realizing the automatic of product proceed and management, it is also the precondition in

13、 the development of informationization. In our country’s traditional estate, using the DC motor speed control actuation account about 85%~90% in the speed contr</p><p>　　1.2 Our Country’s Development Conditi

14、on in Speed Controlled Technique</p><p>　　Our country is a developing country, so many product’s research ability has behind the developed countries. From now on, the product of frequency variation speed con

15、trolled that ourselves made only act for last century 90s in the international. With the reform and opening, rapid development of economic, forms a large market, it opens to the country companies, also the foreign compan

16、ies. Many products are exported from the developed countries, and runs well in our country, satisfied our need in f</p><p>　　As early as in the country "85" technical attack plan, the alternating v

17、elocity modulation technique was listed as the key technical attack project, but because our country’s electric power and electronic device aggregate level is very low, although the production of IGBT、GTO component has i

18、ntroduced the overseas technique, it has not formed the economies of scale benefit, almost does not have the independent development ability of new frequency converter production, this has affected the domest</p>

19、<p>　　Therefore, the AC frequency variation speed control technique has the following sides:</p><p>　　1) The basic research of control strategy in frequency converter has a large gap compares with the f

20、oreign level.</p><p>　　2) The technical level of the whole machine is low in the frequency converter, although we had input certainly people, material resources, but because of the disperse power, did not fo

21、rm a certainly technique and production scale.</p><p>　　3) All the semiconductor power device product in the frequency converter is blank.</p><p>　　4) Correlative Industries and relative Industr

22、ies drop behind.</p><p>　　5) Few production and sale, low reliable and technological standards.</p><p>　　With the development and improvement in the power electronic technique, power divert base

23、d on power electronic circuit technique and various control technique, the AC frequency variation speed controlled technique is mature day by day, and sure to be the main way in the future. With the constant development

24、of power electronic technique, reliable character, well adoption, cheap price that the frequency converter have will become true. This technique will gain widely, popularity application .At p</p><p>　　1.3 Fr

25、equency Variation Speed Controlled Mode</p><p>　　The alternating frequency conversion velocity modulation technique obtained the rapid development in 20th century. This is related with some crucial technical

26、 which gain unprecedented progress, they are Motor vector control technique, Direct torque control technique, PWM technique, Entire numerical control technique and self-setting technique which based on microcomputer and

27、large scale integrated circuit, and so on.</p><p>　　1) Vector Control Technique</p><p>　　Vector transformation control technique is a one kind of new control thought and control theory which pos

28、ed by SIEMENS CO. in 1971. It is realizing the stator current excitation component and the torque component solution lotus root by rotor magnetic field direction detection, and vector transformation, achieved the goal th

29、at separately control the motor flux linkage and the electric current, as a result, obtain finely static, dynamic performance. Until now, the vector control technique has obta</p><p>　　2) Vector Control With

30、out Velocity Generator Technique</p><p>　　Vector control without velocity generator technique abolish the problems that the environment compatibility、install and maintenance bring on, reduce the cost, enhanc

31、e the system reliability, at the same time, union vector control, has the fine performance of vector control. The speed estimate method in vector control technique without velocity generator, besides basis mathematical m

32、odel computation electric motor rotational speed, at present the more applied are the model to refer auto-adapted m</p><p>　　3) Direct Torque Control Technique</p><p>　　In1985, Germany's M.

33、Depen-block proposes the direct torque control technique（DTC） for the first time，The direct torque control technique analyzes the motor mathematical model directly under the stator coordinate system. Uses the stator magn

34、etic field direction detection but not to need the solution lotus root electric current，directly control the electric motor flux linkage and torque, enable the torque to obtain the fast response, in order to obtain the h

35、ighly effective control performance.</p><p>　　Direct torque control technique is another kind of new、high performance alternating frequency conversion velocity modulation technique after vector control techn

36、ique in the nearly 10 years, this kind of control technique is insensitive to the electrical machinery parameter, not influence by the rotor parameter, easy and feasible, it has the broad development and the application

37、prospect.</p><p>　　4) PWM (pulse width modulation) Control Technique</p><p>　　In1964, Germany's A. Schonung and some people took the lead to propose the pulse-duration modulation (PWM -pulse

38、 width modulation) frequency conversion thought, opened the recent development domain for the modern alternating velocity modulation system. The PWM control technique controls the inversion output alternating fundamental

39、 wave voltage peak-to-peak value by changing the rectangle pulse width, controls its output frequency through changing the modulation cycle, in order to carry on the ou</p><p>　　5) Numerical Control Techniqu

40、e</p><p>　　The digitalize in control technique is the key technique of static frequency conversion installment, also will be the next development tendency, at present in the market frequency conversion insta

41、llment nearly comprehensively has realized the numerical control. Has realized the fast operation and the high accuracy control by using the DSP and the ASIC technique, and could gain a fine current wave, reduce the nois

42、e of the frequency converter in a large scale, and the scanning time also be reduced</p><p>　　6) Self-setting Technique</p><p>　　The self-setting technique is widespread used in the frequency co

43、nversion velocity modulation system day by day, it may accord to the speed and the load to auto adjust the parameter of the control system, enable the system with rapid dynamic response. The self-setting technique divide

44、s into off-line and the on-line. The research results in the kind of off-line has been applied in the most production, before the system program operate, it operate a block self-setting program, recognize the correl</

45、p><p>　　2 PLC interference analysis </p><p>　　With the development of science and technology, the application in industrial control of PLC is more and more extensive. The dependability of PLC contr

46、ol system influences the safety in production and economical operation of the industrial enterprise directly; systematic anti-interference ability is the key to concerning the whole system and running reliably. All kinds

47、 of PLC used in the automated system, some install concentrated in the control room , some install in production scene and every </p><p>　　2.1 Sources of interference and interference with the general classi

48、fication </p><p>　　It is like generally influencing the interference source of the industrial control equipment to influence the interference source of PLC control system, mostly producing the position in th

49、e electric current or violent change of voltage, these violent position that move of electric charge is the noise source, namely interfere the source.</p><p>　　Interfere type interfere the division different

50、 from wave form nature of the noise of the mode according to reason, noise produced to interfere usually. Among them: According to reason that noise produce being different, is it discharge noise, wave well up noise, hig

51、h frequency shake noise, etc. to divide into; Different according to the wave form, nature of the noise, divided into a lasting noise, accidental noiseless.; It is different to interfere the mode according to the noise,

52、is divided in</p><p>　　2.2 PLC control system electromagnetic interference the main source</p><p>　　1) The radiation from space interference </p><p>　　mainly produced by temporary a

53、ttitude course , thunder and lightning , radio broadcasting , TV,radar, high-frequency reaction heating device of the electric network , electric equipment ,etc., usually called radiation to interfere, it is extremely co

54、mplicated that it is distributed. Whether if PLC system put on radio frequency in the field is it reaches radiation interfere to retrieve, it influences and mainly passes two routes. First, produced and interferes by the

55、 reaction of the circuit to th</p><p>　　2) Interference from lead wire outside the system</p><p>　　Introduce through the power and signal line mainly, is usually called and conducted interfering

56、. This kind of interference is relatively serious at the industrial scene of our country.</p><p>　　3) Interference from power</p><p>　　Practice has proved , interference introduced because of th

57、e power causes situations of PLC control system trouble a lot of, I meet in debugging in some project, is it isolate performance high PLC power to change, the problem is solved .</p><p>　　Normal power supply

58、 power, PLC of system supply power by the electric wire netting. Because the electric wire netting is widely covered, it will be interfered the voltage of reaction and circuit on the circuit electromagnetically by all sp

59、ace. Change of electric wire netting, enter switch operate wave well up, large-scale electric equipment is it park, is it is it move in harmony wave, electric wire netting that device cause short out the attitude is blud

60、geoned into etc. temporarily to spread di</p><p>　　4) Come from the interference that the signal thread introduces</p><p>　　All kinds of signal transmission lines connected with PLC control syst

61、em, besides transmitting all kinds of effective information, always there will be outside interfering signals that will be invaded. This interference has two kinds of ways mainly: Supply power or share through changer po

62、wer supply power a bunch of electric wire netting entered, signal of instrument interfere, this is often ignored; second, the signal line is influenced by space electromagnetic radiation reaction, namely the ex</p>

63、<p>　　5) Interference while coming from the earth system confusedly</p><p>　　Earth to improve electronic equipment electromagnetic effective means of compatibility one of. Correct earth, can suppress

64、 the equipment to send out and interfere outwards not only can suppress the electromagnetic influence that interfere but also; And wrong earth, can introduce serious interfering signal instead , make PLC to be system una

65、ble to work normally .</p><p>　　6) The ground wire including systematic ground , shielding , exchanging of PLC control system and protect the ground etc..Earth whether all connect the place electric potentia

66、l misdistributions mainly to interference, PLC of system, different to connect person who have electric potential difference under place, person who cause cycle electric current, influence the system to work normally. Fo

67、r example cable shielding layer must one point ground, if cable shielding layer both ends A, B ground, pe</p><p>　　In addition, the shielding layer , earth connection and earth may be formed and closed the c

68、ycle, under changing the function of the magnetic field , will present the reaction electric current in the shielding layer, pass the coupling between the shielding layer and core line , the return circuit of interfering

69、 signal. If with deal with confusion by other earth systematically, ground circulation produced might is it vary the electric potential distribute to produce at ground wire, influence the </p><p><b>　　

70、附錄二</b></p><p><b>　　中文翻譯：變頻技術(shù)</b></p><p>　　1.1 變頻技術(shù)的普及前景</p><p>　　電機(jī)交流變頻調(diào)速技術(shù)是當(dāng)今節(jié)電、改善工藝流程以提高產(chǎn)品質(zhì)量和改善環(huán)境、推動(dòng)技術(shù)進(jìn)步的一種主要手段。變頻調(diào)速以其優(yōu)異的調(diào)速和起制動(dòng)性能，高效率、高功率因數(shù)和節(jié)電效果，廣泛的適用范圍及其它許多優(yōu)點(diǎn)而

71、被國(guó)內(nèi)外公認(rèn)為最有發(fā)展前途的調(diào)速方式。電氣傳動(dòng)控制系統(tǒng)通常由電動(dòng)機(jī)、控制裝置和信息裝置3部分組成，電氣傳動(dòng)關(guān)系到合理地使用電動(dòng)機(jī)以節(jié)約電能和控制機(jī)械的運(yùn)轉(zhuǎn)狀態(tài)，實(shí)現(xiàn)電能-機(jī)械能的轉(zhuǎn)換，達(dá)到優(yōu)質(zhì)、高產(chǎn)、低耗目的。電氣傳動(dòng)分成不調(diào)速和調(diào)速兩大類，調(diào)速又分交流調(diào)速和直流調(diào)速兩種方式。不調(diào)速電動(dòng)機(jī)直接由電網(wǎng)供電，但隨著電力電子技術(shù)的發(fā)展這類原本不調(diào)速的機(jī)械越來越多地改用調(diào)速傳動(dòng)以節(jié)約電能(節(jié)約15%~20%或更多)，改善產(chǎn)品質(zhì)量，提高產(chǎn)量。在我

72、國(guó)60%的發(fā)電量是通過電動(dòng)機(jī)消耗的，因此調(diào)速傳動(dòng)是一個(gè)重要行業(yè)，已經(jīng)得到國(guó)家重視，目前已有一定規(guī)模。</p><p>　　近年來交流調(diào)速中最活躍、發(fā)展最快的就是變頻調(diào)速技術(shù)，變頻調(diào)速是交流調(diào)速的基礎(chǔ)和主干內(nèi)容。上個(gè)世紀(jì)變壓器的出現(xiàn)使改變電壓變得很容易，從而造就了一個(gè)龐大的電力行業(yè)。長(zhǎng)期以來，交流電的頻率一直是固定的，變頻調(diào)速技術(shù)的出現(xiàn)使頻率變?yōu)榭梢猿浞掷玫馁Y源。</p><p>　　這1

73、0年來，變頻技術(shù)的應(yīng)用在我國(guó)有很大的發(fā)展，并取得了良好的效果可以說，變頻技術(shù)已為大多數(shù)用戶所接受，但是不能不指出，我國(guó)在變頻技術(shù)的應(yīng)用方面，與發(fā)達(dá)國(guó)家的水平尚有很大差距，目前，我國(guó)在用的交流電動(dòng)機(jī)使用變頻調(diào)速運(yùn)行的僅6%左右，而下業(yè)發(fā)達(dá)國(guó)家已達(dá)(60%~70%)，日本在風(fēng)機(jī)、水泵上變頻調(diào)速的采用率已達(dá)10% ,而我國(guó)還不足0.01%.在日本，空調(diào)器的70%采用了變頻調(diào)速，而我國(guó)才剛剛起步。從這個(gè)現(xiàn)實(shí)出發(fā)，變頻技術(shù)尚有很大的發(fā)展空間，應(yīng)該

74、鍥而不舍地做好推廣應(yīng)用工作。</p><p>　　而且隨著控制技術(shù)和控制手段的不斷提高，變頻調(diào)速又由變壓變頻控制的變頻調(diào)速發(fā)展到了矢量控制變頻調(diào)速，通過控制交流電動(dòng)機(jī)里相當(dāng)于并勵(lì)直流電動(dòng)機(jī)勵(lì)磁繞組的磁通變化，提高變頻器的恒轉(zhuǎn)矩輸出范圍和動(dòng)靜態(tài)特性，使得交流電動(dòng)機(jī)變頻調(diào)速系統(tǒng)的性能超過了直流電動(dòng)機(jī)調(diào)壓調(diào)速系統(tǒng)的性能。為了簡(jiǎn)化控制系統(tǒng)，減少設(shè)備故障率，在矢量控制變頻調(diào)速的基礎(chǔ)上又發(fā)展了無速度傳感器的矢量控制變頻調(diào)速。

75、在一些對(duì)動(dòng)靜態(tài)特性要求不太高的應(yīng)用中，無速度傳感器的矢量控制變頻調(diào)速己完全可以和有速度傳感器的矢量控制變頻調(diào)速相媲美。矢量控制對(duì)交流電機(jī)調(diào)速具有劃時(shí)代的意義。</p><p>　　變頻調(diào)速是電機(jī)調(diào)速的最佳方式，是企業(yè)技術(shù)改造和產(chǎn)品更新?lián)Q代的理想設(shè)備，是工業(yè)自動(dòng)化系統(tǒng)必不可少的組成部分，是實(shí)現(xiàn)生產(chǎn)過程和管理自動(dòng)化的前提，也是信息化發(fā)展的先決條件。在我國(guó)傳統(tǒng)產(chǎn)業(yè)中，采用直流電機(jī)拖動(dòng)的調(diào)速系統(tǒng)約占調(diào)速系統(tǒng)總量的85%~

76、90%，而交流調(diào)速系統(tǒng)僅占10%~15%。效率低、質(zhì)量差、消耗大、故障率高己成為制約企業(yè)發(fā)展的瓶頸。因此，必須積極推廣先進(jìn)的交流變頻調(diào)速技術(shù)，用先進(jìn)的設(shè)備武裝傳統(tǒng)產(chǎn)業(yè)，促進(jìn)自動(dòng)化、工業(yè)化和信息化的進(jìn)一步發(fā)展。</p><p>　　1.2 變頻調(diào)速發(fā)展趨勢(shì)</p><p>　　如果說以第一個(gè)晶閘管的出現(xiàn)作為交流電動(dòng)機(jī)變頻調(diào)速的起點(diǎn)，可以認(rèn)為它的發(fā)展歷史己40多年了。而變頻調(diào)速技術(shù)真正高速發(fā)展

77、時(shí)期，應(yīng)該是在PWM調(diào)制技術(shù)的出現(xiàn)和微機(jī)控制技術(shù)發(fā)展之后。特別是最近20年來，隨著交流調(diào)速技術(shù)的應(yīng)用普及，交流變頻調(diào)速在化工、火電廠、礦山、油田、機(jī)械制造、城市建設(shè)、水處理、甚至家電等行業(yè)己經(jīng)全面推廣使用，一般主要用于節(jié)能及控制。隨著變頻技術(shù)的普及和深入，以及國(guó)際、國(guó)內(nèi)電器設(shè)備使用的有關(guān)標(biāo)準(zhǔn)意識(shí)的強(qiáng)化，電力系統(tǒng)行業(yè)和用戶對(duì)變頻技術(shù)的質(zhì)量要求也越來越高。變頻調(diào)速的發(fā)展趨勢(shì)主要圍繞下面幾個(gè)方而展開。</p><p>

78、　　1) 高性能的智能控制變頻器</p><p>　　380V系統(tǒng)的低壓變頻器是國(guó)內(nèi)的主要研究對(duì)象，應(yīng)用交流調(diào)速的基本理論，結(jié)合神經(jīng)網(wǎng)絡(luò)控制、魯棒控制、模糊控制，或其他智能控制等手段，實(shí)現(xiàn)電機(jī)運(yùn)行參數(shù)的自動(dòng)辨識(shí)，以期達(dá)到自適應(yīng)、自調(diào)整的最優(yōu)控制。這方面己有一定的研究成果。</p><p>　　2) 速度傳感器研究</p><p>　　從前面所述的各種變頻調(diào)速的理論可

79、知，一般系統(tǒng)都要用到轉(zhuǎn)速傳感器。在實(shí)際使用中，由于變頻設(shè)備和被控電動(dòng)機(jī)有一定的距離，而高精度的轉(zhuǎn)速傳感器都要使用專門的電源，被控電動(dòng)機(jī)有的是在戶外，運(yùn)行工況非常惡劣，要保證速度反饋的準(zhǔn)確性，有時(shí)不得不采取特別措施，因此也會(huì)增加額外費(fèi)用，運(yùn)行的可靠性和控制精度也會(huì)因此受到影響。無速度傳感器的變頻調(diào)速系統(tǒng)，是通過現(xiàn)場(chǎng)采集的電流電壓量，以及控制的實(shí)施策略，綜合出被控電機(jī)的實(shí)際轉(zhuǎn)速。這種控制方案要求計(jì)算機(jī)的控制速度較高，并有足夠的精度。<

80、/p><p>　　3) 針對(duì)功率因數(shù)提高和諧波污染的研究</p><p>　　低壓變頻調(diào)速系統(tǒng)的控制雖然己經(jīng)是非常成熟了，但目前國(guó)際、國(guó)內(nèi)的產(chǎn)品，一般都是矢量控制和直接轉(zhuǎn)矩控制，重點(diǎn)放在電機(jī)變頻控制理論的實(shí)現(xiàn)和完善上，而對(duì)變頻器的輸出波形、功率因數(shù)，以及諧波污染等問題還沒有引起足夠的重視。最近10多年來，國(guó)外在這一領(lǐng)域己有較深入的研究。有的針對(duì)功率因數(shù)，有的強(qiáng)調(diào)輸出波形。多重化技術(shù)就是為了解決

81、輸出波形問題。最近幾年的研究表明，利用PWM輸出控制解決諧波輸出問題，是比較理想的方法，它可以省去多重化中的變壓器，或過多的開關(guān)元器件，使變頻器的體積和重量減少，但這種方法不能解決所有諧波的消除問題，只能部分消除特定諧波。這方面的研究論文還不多，也還沒有成熟的類似低壓變頻器的產(chǎn)品出現(xiàn)。</p><p>　　4) 高壓變頻器的研究</p><p>　　變頻器的主要作用之一是節(jié)能。而高壓電動(dòng)機(jī)

82、的節(jié)能效果是比較明顯的，大功率的風(fēng)機(jī)和水泵用電動(dòng)機(jī)一般都是高壓電動(dòng)機(jī)。國(guó)內(nèi)，高壓變頻調(diào)速和它的節(jié)能控制還是一個(gè)比較薄弱的環(huán)節(jié).它主要是針對(duì)6~10kV的交流電動(dòng)機(jī)進(jìn)行變頻調(diào)速控制。這種高壓電動(dòng)機(jī)廣泛應(yīng)用于火力發(fā)電廠的送風(fēng)機(jī)和引風(fēng)機(jī)上。同樣也可用于其他如石油化工、礦山、冶煉、機(jī)械制造等行業(yè)的變頻節(jié)能控制。從某種意義上講，由于目前國(guó)內(nèi)還不能完全生產(chǎn)高質(zhì)量的合格電力電子器件，而且，國(guó)外低壓變頻器的性能價(jià)格比也比國(guó)內(nèi)自己研究的變頻器高得多。因此

83、,在這方面還有許多研究工作要做。</p><p>　　隨著電力電子技術(shù)最近20多年的飛速發(fā)展，功率半導(dǎo)體器件的成本逐年下降，技術(shù)工藝和性能也得到不斷改善.電力電子器件的應(yīng)用己從傳統(tǒng)的直流調(diào)速、直流屏、斬波器等領(lǐng)域延伸到交流調(diào)速和電力系統(tǒng)的質(zhì)量控制領(lǐng)域.并正朝著高電壓、大功率的方向發(fā)展.這也是千年之交和世紀(jì)之交我國(guó)電力電子技術(shù)應(yīng)用的發(fā)展趨勢(shì)。</p><p>　　5) 無換向器同步電機(jī)的變頻

84、調(diào)速</p><p>　　無換向器電動(dòng)機(jī)也是在20世紀(jì)70年代發(fā)展起來的新型調(diào)速系統(tǒng)。它是一種變頻調(diào)速同步電動(dòng)機(jī).也可以認(rèn)為是一種用半導(dǎo)體電子開關(guān)線路代替換向器和電刷作用的直流電動(dòng)機(jī)。根據(jù)采用的控制方式不同.可分為直流無換向器電動(dòng)機(jī)和交流無換向器電動(dòng)機(jī)。直流無換向器電動(dòng)機(jī)采用交-直-交或直-交變頻控制系統(tǒng);交流無換向器電動(dòng)機(jī)采用交-交變頻控制系統(tǒng)。近10年來.國(guó)內(nèi)外雜志上有許多相關(guān)的研究論文。而且，也有一定的成果

85、出現(xiàn)。</p><p>　　1.3 變頻調(diào)速控制方式</p><p>　　交流變頻調(diào)速技術(shù)在20世紀(jì)得到了迅速發(fā)展。這與一些關(guān)鍵性技術(shù)的突破性進(jìn)展有關(guān)，它們是交流電動(dòng)機(jī)的矢量控制技術(shù)、直接轉(zhuǎn)矩控制技術(shù)、PWM技術(shù)以及微型計(jì)算機(jī)和大規(guī)模集成電路為基礎(chǔ)的全數(shù)字化控制技術(shù)、自整定技術(shù)等。</p><p><b>　　1) 矢量控制技術(shù)</b><

86、/p><p>　　矢量變換控制技術(shù)是西門子公司于1971年提出的一種新的控制思想和控制理論。它是以轉(zhuǎn)子磁場(chǎng)定向，采用矢量變換的方法實(shí)現(xiàn)定子電流勵(lì)磁分量和轉(zhuǎn)矩分量之間的解藕，達(dá)到對(duì)交流電動(dòng)機(jī)的磁鏈和電流分別控制的目的，從而獲得了優(yōu)良的靜、動(dòng)態(tài)性能。迄今為止，矢量控制技術(shù)己經(jīng)獲得了長(zhǎng)足的發(fā)展，并得到了廣泛應(yīng)用。</p><p>　　2) 無速度傳感器矢量控制技術(shù)</p><p&

87、gt;　　無速度傳感器控制技術(shù)免去了傳感器帶來的環(huán)境適應(yīng)性、安裝維護(hù)等問題，降低了成本，提高了系統(tǒng)的可靠性，同時(shí)結(jié)合矢量控制，具有矢量控制的優(yōu)良性能。無速度傳感器技術(shù)中速度估算的方法，除了根據(jù)數(shù)學(xué)模型計(jì)算電動(dòng)機(jī)轉(zhuǎn)速外，目前應(yīng)用較多的有模型參考自適應(yīng)法和擴(kuò)展卡爾曼濾波法。此外全維轉(zhuǎn)子磁通觀測(cè)器，齒諧波電勢(shì)(RSH)等理論也出現(xiàn)在無速度傳感器技術(shù)中。從1983年提出無速度傳感器矢量控制策略以來，一直受到學(xué)術(shù)界和產(chǎn)業(yè)界的高度重視，日立、安川電

88、機(jī)等公司在1987年分別發(fā)表了研究成果，并相繼推出了產(chǎn)品。目前，無速度傳感器矢量控制變頻器的調(diào)速范圍為1:50左右，個(gè)別廠商有1:75甚至更高的產(chǎn)品。</p><p>　　3) 直接轉(zhuǎn)矩控制技術(shù)</p><p>　　1985年.德國(guó)的M . Depen-block首次提出直接轉(zhuǎn)矩控制技術(shù)(DTC)。DTC控制直接在定子坐標(biāo)系下分析交流電動(dòng)機(jī)的數(shù)學(xué)模型。采用定子磁場(chǎng)定向而無需解藕電流，直接控

89、制電動(dòng)機(jī)的磁鏈和轉(zhuǎn)矩，以使轉(zhuǎn)矩得到快速響應(yīng)，從而獲得高效的控制性能。</p><p>　　直接轉(zhuǎn)矩控制技術(shù)是近10年繼矢量控制技術(shù)之后發(fā)展起來的又一種新型的高性能交流變頻調(diào)速技術(shù)，這種控制技術(shù)與矢量控制技術(shù)相比，對(duì)電機(jī)參數(shù)不敏感，不受轉(zhuǎn)子參數(shù)的影響，簡(jiǎn)單易行，具有廣闊的發(fā)展和應(yīng)用前景。</p><p>　　4) PWM控制技術(shù)</p><p>　　1964年，德國(guó)的

90、A. Schonung等率先提出了脈寬調(diào)制(PWM -pulse width modulation)變頻的思想，為近代交流調(diào)速系統(tǒng)開辟了新的發(fā)展領(lǐng)域。PWM控制技術(shù)通過改變矩形脈沖的寬度來控制逆變器輸出交流基波電壓的幅值，通過改變調(diào)制周期來控制其輸出頻率，從而在逆變器上同時(shí)進(jìn)行輸出電壓幅值和頻率的控制。PWM技術(shù)簡(jiǎn)化了逆變器的結(jié)構(gòu)，能夠明顯的改善變頻器的輸出波形，降低電動(dòng)機(jī)的諧波損耗，并減小轉(zhuǎn)矩脈動(dòng)，同時(shí)提高了系統(tǒng)的動(dòng)態(tài)響應(yīng)性能。PWM

91、技術(shù)還可用于整流器的控制，能夠?qū)崿F(xiàn)輸入電流非常接近正弦.。并可使電網(wǎng)功率因數(shù)為1。PWM整流器因而被稱為“綠色”變流器。目前，PWM技術(shù)己成為變頻器中應(yīng)用最為廣泛的控制技術(shù)。交流電機(jī)調(diào)速性能的不斷提高在很大程度上是由于PWM技術(shù)的不斷進(jìn)步。目前廣泛應(yīng)用的是在規(guī)則采樣PWM的基礎(chǔ)上發(fā)展起來的準(zhǔn)優(yōu)化PWM法，即三次諧波疊加法和電壓空間矢量PWM法。</p><p>　　5) 數(shù)字化控制技術(shù)</p>&l

92、t;p>　　控制技術(shù)的數(shù)字化是靜止變頻裝置的核心技術(shù)，也是今后的發(fā)展趨勢(shì)。目前市場(chǎng)上的變頻裝置幾乎全面實(shí)現(xiàn)了數(shù)字化控制。采用DSP和ASIC技術(shù)實(shí)現(xiàn)了快速運(yùn)算和高精度控制，可以得到良好的電流波形，使變頻器的噪音大幅度降低，并且掃描時(shí)間大幅度縮短，目前電流響應(yīng)為0.1~0.7ms，速度響應(yīng)為2~4 ms,足以滿足傳動(dòng)領(lǐng)域的控制要求。同時(shí)由于應(yīng)用微電子技術(shù)和ASIC技術(shù)，裝置的元器件數(shù)量得以大幅度減少，從而使變頻裝置的體積減小，可靠性

93、得到大幅度提高。全數(shù)字控制方式使變頻器的信息處理能力大為增強(qiáng)。采用模擬控制方式無法實(shí)現(xiàn)的復(fù)雜控制在今天都己成為現(xiàn)實(shí)，從而所謂的RAS概念即可靠性(Reliability)、可操作性(Availability)、可維修性(Serviceability)得以充實(shí)。</p><p><b>　　6) 自整定技術(shù)</b></p><p>　　自整定技術(shù)在變頻調(diào)速系統(tǒng)中的應(yīng)用日

94、益廣泛，它可以根據(jù)速度和負(fù)載的變化自動(dòng)調(diào)整控制系統(tǒng)的參數(shù)，使得系統(tǒng)具有快速的動(dòng)態(tài)響應(yīng)。自整定技術(shù)分為離線式和在線式兩種。離線式的研究成果己經(jīng)在相當(dāng)多的產(chǎn)品中應(yīng)用，它是在運(yùn)行系統(tǒng)程序之前通過運(yùn)行一段自整定程序，辨識(shí)相關(guān)數(shù)據(jù)，并修改系統(tǒng)程序的相關(guān)參數(shù)，以期獲得良好的系統(tǒng)控制性能。另外，改進(jìn)控制技術(shù)，提高系統(tǒng)魯棒性也和自整定技術(shù)緊密相聯(lián)系。</p><p>　　2 PLC抗干擾分析</p><p&g

95、t;　　隨著科學(xué)技術(shù)的發(fā)展，PLC在工業(yè)控制中的應(yīng)用越來越廣泛。PLC控制系統(tǒng)的可靠性直接影響到工業(yè)企業(yè)的安全生產(chǎn)和經(jīng)濟(jì)運(yùn)行，系統(tǒng)的抗干擾能力是關(guān)系到整個(gè)系統(tǒng)可靠運(yùn)行的關(guān)鍵。自動(dòng)化系統(tǒng)中所使用的各種類型PLC，有的是集中安裝在控制室，有的是安裝在生產(chǎn)現(xiàn)場(chǎng)和各電機(jī)設(shè)備上，它們大多處在強(qiáng)電電路和強(qiáng)電設(shè)備所形成的惡劣電磁環(huán)境中。要提高PLC控制系統(tǒng)可靠性，一方面要求PLC生產(chǎn)廠家用提高設(shè)備的抗干擾能力；另一方面，要求工程設(shè)計(jì)、安裝施工和使用維

96、護(hù)中引起高度重視，多方配合才能完善解決問題，有效地增強(qiáng)系統(tǒng)的抗干擾性能。 </p><p>　　2.1 干擾源及干擾一般分類</p><p>　　影響PLC控制系統(tǒng)的干擾源與一般影響工業(yè)控制設(shè)備的干擾源一樣，大都產(chǎn)生在電流或電壓劇烈變化的部位，這些電荷劇烈移動(dòng)的部位就是噪聲源，即干擾源。 </p><p>　　干擾類型通常按干擾產(chǎn)生的原因、噪聲干擾模式和噪聲的波形性

97、質(zhì)的不同劃分。其中：按噪聲產(chǎn)生的原因不同，分為放電噪聲、浪涌噪聲、高頻振蕩噪聲等；按噪聲的波形、性質(zhì)不同，分為持續(xù)噪聲、偶發(fā)噪聲等；按噪聲干擾模式不同，分為共模干擾和差模干擾。共模干擾和差模干擾是一種比較常用的分類方法。共模干擾是信號(hào)對(duì)地的電位差，主要由電網(wǎng)串入、地電位差及空間電磁輻射在信號(hào)線上感應(yīng)的共態(tài)(同方向)電壓迭加所形成。共模電壓有時(shí)較大，特別是采用隔離性能差的配電器供電室，變送器輸出信號(hào)的共模電壓普遍較高，有的可高達(dá)130V以

98、上。共模電壓通過不對(duì)稱電路可轉(zhuǎn)換成差模電壓，直接影響測(cè)控信號(hào)，造成元器件損壞(這就是一些系統(tǒng)I/O模件損壞率較高的主要原因)，這種共模干擾可為直流、亦可為交流。差模干擾是指作用于信號(hào)兩極間的干擾電壓，主要由空間電磁場(chǎng)在信號(hào)間耦合感應(yīng)及由不平衡電路轉(zhuǎn)換共模干擾所形成的電壓，這種讓直接疊加在信號(hào)上，直接影響測(cè)量與控制精度。 </p><p>　　2.2 PLC控制系統(tǒng)中電磁干擾的主要來源 </p>&l

99、t;p>　　1) 來自空間的輻射干擾 </p><p>　　空間的輻射電磁場(chǎng)(EMI)主要是由電力網(wǎng)絡(luò)、電氣設(shè)備的暫態(tài)過程、雷電、無線電廣播、電視、雷達(dá)、高頻感應(yīng)加熱設(shè)備等產(chǎn)生的，通常稱為輻射干擾，其分布極為復(fù)雜。若PLC系統(tǒng)置于所射頻場(chǎng)內(nèi)，就回收到輻射干擾，其影響主要通過兩條路徑：一是直接對(duì)PLC內(nèi)部的輻射，由電路感應(yīng)產(chǎn)生干擾；而是對(duì)PLC通信內(nèi)網(wǎng)絡(luò)的輻射，由通信線路的感應(yīng)引入干擾。輻射干擾與現(xiàn)場(chǎng)設(shè)備布置