電力電子技術(shù)外文翻譯

1、<p><b>　　畢業(yè)論文（設(shè)計）</b></p><p><b>　　外文翻譯</b></p><p>　　題 目： 電力電子技術(shù)二 </p><p>　　系部名稱： 專業(yè)班級： </p><p>

2、　　學(xué)生姓名： 學(xué) 號： </p><p>　　指導(dǎo)教師： 教師職稱： </p><p>　　20 年 3 月 15日</p><p><b>　　電力電子技術(shù)（二）</b></p><p><b>　　

3、A部分</b></p><p><b>　　晶閘管</b></p><p>　　在晶閘管的工作狀態(tài)，電流從陽極流向陰極。在其關(guān)閉狀態(tài)，晶閘管可以阻止正向</p><p>　　導(dǎo)電，使其不能運行。</p><p>　　可觸發(fā)晶閘管能使導(dǎo)通狀態(tài)的正向電流在短時間內(nèi)使設(shè)備處于阻斷狀態(tài)。 使正向電壓下降到只有導(dǎo)通狀態(tài)

4、的幾伏（通常為1至3伏電壓依賴于阻斷電壓的速度）。</p><p>　　一旦設(shè)備開始進行，閘極電流將被隔離。晶閘管不可能被閘關(guān)閉，但是可以作為一個二極管。在電路的中，只有當(dāng)電流處于消極狀態(tài)，才能使晶閘管處于關(guān)閉狀態(tài)，且電流降為零。在設(shè)備運行的時間內(nèi)，允許閘在運行的控制狀態(tài)直到器件在可控時間再次進入正向阻斷狀態(tài)。</p><p>　　在逆向偏置電壓低于反向擊穿電壓時，晶閘管有微乎其微的漏電流

5、。通常晶閘管的正向額定電壓和反向阻斷電壓是相同的。晶閘管額定電流是在最大范圍指定RMS和它是有能力進行平均電流。同樣的對于二極管，晶閘管在分析變流器的結(jié)構(gòu)中可以作為理想的設(shè)備。在一個阻性負載電路中的應(yīng)用中，可以控制運行中的電流瞬間傳至源電壓的正半周期。當(dāng)晶閘管嘗試逆轉(zhuǎn)源電壓變?yōu)樨撝禃r，其理想化二極管電流立刻變成零。</p><p>　　然而，按照數(shù)據(jù)表中指定的晶閘管，其反向電流為零。在設(shè)備不運行的時間中，電流為零

6、，重要的參數(shù)變也為零，這是轉(zhuǎn)彎時間區(qū)間從零交叉電流電壓的參考。晶閘管必須保持在反向電壓，只有在這個時間，設(shè)備才有能力阻止它不是處于正向電壓導(dǎo)通狀態(tài)。</p><p>　　如果一個正向電壓應(yīng)用于晶閘管的這段時間已過，設(shè)備可能因為過早地啟動并有可能導(dǎo)致設(shè)備和電路損害。數(shù)據(jù)表指定晶閘管通過的反向電壓在這段期間和超出這段時間外的一個指定的電壓上升率。這段期間有時被稱為晶閘管整流電路的周期。</p><

7、p>　　根據(jù)使用要求，各種類型的晶閘管是可得到的。在除了電壓和電流的額定率，轉(zhuǎn)彎時間，和前方的電壓降以及其他必須考慮的特性包括電流導(dǎo)通的上升率和在關(guān)閉狀態(tài)的下降率。 </p><p>　　1?？刂凭чl管階段。 有時稱為晶閘管轉(zhuǎn)換器，這些都是用來要是整頓階段，如為直流和交流電機驅(qū)動器和高壓直流輸電線路應(yīng)用的電壓和電流的驅(qū)動。主要設(shè)備要求是在大電壓、電流導(dǎo)通狀態(tài)或低通態(tài)壓降中。這類型的晶閘管的生產(chǎn)晶圓直徑到10

8、厘米，其中平均電流目前大約是4000A，阻斷電壓為5之7KV。 2。逆變級的晶閘管。這些設(shè)計有小關(guān)斷時間，除了低導(dǎo)通狀態(tài)電壓，雖然在設(shè)備導(dǎo)通狀態(tài)電壓值較小，可設(shè)定為2500V和1500A。他們的關(guān)斷時間通常在幾微秒范圍到100μs之間，取決于其阻斷電壓的速率和通態(tài)壓降。 3。光控晶閘管。這些會被一束脈沖光纖觸發(fā)使其被引導(dǎo)到一個特殊的敏感的晶閘管地區(qū)。光化的晶閘管觸發(fā)，是使用在適當(dāng)波長的光的對硅產(chǎn)生多余的電子空穴。這些

9、晶閘管的主要用途是應(yīng)用在高電壓，如高壓直流系統(tǒng)，有許多晶閘管被應(yīng)用在轉(zhuǎn)換器閥門上。光控晶閘管已經(jīng)發(fā)現(xiàn)的等級，有4kV的3kA，導(dǎo)通狀態(tài)電壓2V、光觸發(fā)5毫瓦的功率要求。 </p><p>　　還有其它一些晶閘管，如輔助型關(guān)斷晶閘管（關(guān)貿(mào)總協(xié)定），這些晶閘管其他變化，不對稱硅可控（ASCR）和反向進行，晶閘管（RCT）的。這些都是應(yīng)用。</p><p><b>　　B部

10、分</b></p><p>　　功率集成電路功率集成電路的種類</p><p>　　現(xiàn)代半導(dǎo)體功率控制相當(dāng)數(shù)量的電路驅(qū)動，除了電路功率器件本身。 這些控制電路通常由微處理器控制，其中包括邏輯電路。這種在同一芯片上包含或作為功率器件來控制和驅(qū)動電路將大大簡化了整個電路的設(shè)計和擴大潛在的應(yīng)用范圍。這樣的整合將會產(chǎn)生一個更便宜和更可靠的電源控制系統(tǒng)?？偟膩碚f，將減少復(fù)雜性（較少獨立

11、電路和使用這類功率集成電路系統(tǒng)組件）。 這樣的整合已經(jīng)被證明有很多應(yīng)用。 這里有三個類功率積體電路包括所謂的智能或智能開關(guān)，高電壓集成電路（HVIC能夠）和離散模塊。功率集成電路領(lǐng)域，特別是智能交換機和HVIC，被認為是500-100 A和目前的水平相差約1000伏或更少。離散模塊涵蓋更廣泛的電壓電流范圍。 </p><p>　　智能開關(guān)垂直電力及其他組件的設(shè)備，而無需動力裝置的垂直過程的順序是可行

12、的。 如片上的過流和過溫傳感器，以及驅(qū)動部分都是可用的，可以包含例子。PN結(jié)形成的N - 漂移地區(qū)和P -區(qū)域始終是反向偏置，如果垂直功率場效應(yīng)管的漏極是相對于電源，從而積極為這個路口提供了電氣隔離之間的橫向和縱向的場效應(yīng)管。高電壓（HVIC）集成電路都采用傳統(tǒng)的邏輯設(shè)備制造過程，但一些修改，使橫向高電壓設(shè)備也可兼容低電壓的設(shè)備。兩個簡單的例子，每個在其中的各種設(shè)備之間實現(xiàn)了電氣隔離的方式不相同，HVIC有更多的復(fù)雜性。 </p&

13、gt;<p>　　離散模塊是由多個芯片安裝在一個共同的絕緣基板，密封成一個包。他不包括各種芯片垂直器件，驅(qū)動電路芯片和控制電路芯片（甚至一個PWM控制器），以及其他可能的功能。盡管這種方法并不是一個完全集成制造方法，但是我們有潛力，因為它目前廣泛應(yīng)用在智能開關(guān)或HVIC。</p><p>　　石化商業(yè)化所面臨的挑戰(zhàn)</p><p>　　使用整合的電力電子電路面臨幾個經(jīng)濟和技術(shù)

14、方面的挑戰(zhàn)。技術(shù)問題包括:</p><p>　　1。電氣隔離從低電壓元件高壓元件。2。熱管理功率器件，通常工作在更高的溫度下的成套設(shè)備。3。高壓導(dǎo)線上的互連芯片運行在低電壓設(shè)備或低電壓地區(qū)。4。制造過程中必須提供的設(shè)備和組件的完整范圍 </p><p>　　除了晶體管二極管、電阻、電容此外，功率集成電路使用面臨許多經(jīng)濟問題。 這些包括：1。大量的前期開發(fā)成本之前，任何生產(chǎn)運行。2

15、。成本差異的三種類型。3。需要大批量應(yīng)用到恢復(fù)大開發(fā)費用。</p><p>　　在解決挑戰(zhàn)的研究進展</p><p>　　低壓設(shè)備與來自高壓元素，也可以實現(xiàn)介電分離、PN結(jié)分離、或自己分離。介質(zhì)隔離能實現(xiàn)兩種方式。隔離主要由蝕刻切片或晶圓片上面生長著一層二氧化矽。其次，把矽沉積在二氧化硅中。沉積下來的硅退火后的，高溫，在再結(jié)晶過程中，可以用于制作低壓設(shè)備。介質(zhì)隔離是免費的寄生設(shè)備，如二極

16、管。</p><p><b>　　C部分</b></p><p>　　硅控整流器（SCR）</p><p>　　SCR已成為大功率電器的重要組成部分和信號調(diào)理控制的一部分。在某些方面，它是一個固態(tài)繼電器的替換品，雖然在某些方面還有一些差距。在理想中的標(biāo)準(zhǔn)二極管，是一個單向傳導(dǎo)電流的器件。在理想的意義上可控硅整流器，就像是一個二極管不會在任何一個

17、方向進行，直到它被打開或關(guān)閉。注相似一個二極管，但添加了終端，叫做門。如果SCR是向前偏見，否則就無法行為?，F(xiàn)在，假設(shè)一個電壓，就放在陰極門。會有一些積極的電壓值 - 觸發(fā)電壓 - 其中可控硅將開始進行陽極陰極和行為像一個正常的二極管。即使門電壓拿走，它也會繼續(xù)進行這樣一個二極管，這是，一旦打開，將為零，無論門。只有這樣，才能把可控硅回“關(guān)”是有正向偏壓條件下帶走。這意味著電壓必須跌破的可控硅的正向壓降，使低于最低值，電流下降稱為維持電

18、流，或從陽極陰極必須實際極性相反。認為可控硅不能輕易被關(guān)閉的事實限制了它在直流應(yīng)用到那些下面的一些減少持有正向電流值的方法可以提供案件。在交流電路中，可控硅整流器自動打開時，在每半個周期的交流電壓施加到可控硅的極性就會相反。</p><p>　　可控硅的特點及規(guī)格如下。1。最大正向電流。有一個最大電流可控硅可以放在正向電流中，不會損壞。此值各不相同，從幾百毫安還有千余毫安放大器，大型工業(yè)類型。2。反向峰值電壓

19、。一個二極管，有一個額外相反偏差電壓電壓那能適用于控硅整流器無損害。他們的值不同，幾個伏特到幾千伏特。3。觸發(fā)電壓。最低柵極電壓來驅(qū)動不同的可控硅導(dǎo)通類型之間的大小，從幾伏到40V。4。觸發(fā)電流。有一個最低的觸發(fā)電流，在提供電壓源前必須SCR可以被關(guān)閉。幾個值有所不同，從幾毫安到幾百毫安。5。保持電流。這是指最低陽極對陰極電流必要可控硅保持在正向?qū)щ姞顟B(tài)進行。該值從20到100毫安。</p><p><

20、;b>　　AC操作</b></p><p>　　一個變化中的可控硅的是以半波運行的直流電壓RMS操作。觸發(fā)電壓是由一些電路研制生產(chǎn)在一定的外加交流信號選擇階段的脈沖。因此，在可控硅打開一個重復(fù)的方式，如圖所示。 SCR關(guān)閉，當(dāng)然，在每半個周期當(dāng)AC極性反轉(zhuǎn)。通過改變部分正半周時，觸發(fā)應(yīng)用，有效（RMS）的直流電壓值應(yīng)用于負載可提高。當(dāng)然，這可能是此直流電壓半波整流電路的最大有效值。如果需要更多的

21、電源，可選用可控硅全波橋式電路。觸發(fā)電壓，現(xiàn)在必須在每半個周期產(chǎn)生并應(yīng)用到可控硅觸發(fā)（門）終端。在過程控制應(yīng)用中，控制器的輸出信號將被用來驅(qū)動電路，改變了在該脈沖被應(yīng)用到門，從而改變了通電的載入時間。加到負載上的電壓脈動直流。此配置不能用于帶負荷操作，需要交流電壓。</p><p><b>　　觸發(fā)控制 </b></p><p>　　SCR在過程控制的應(yīng)用，電路控制

22、信號轉(zhuǎn)換成合適的觸發(fā)信號傳送到SCR是必需的。這樣的電路通常是由電子系統(tǒng)組成，該系統(tǒng)使用的控制電壓決定交流負載電壓。</p><p>　　控制信號電壓通過一個指示燈來提供相應(yīng)的驅(qū)動器晶體管，從而確保了電源電路控制電路隔離。在低基數(shù)驅(qū)動電容充電慢，直到不會達到周期后期的可控硅的觸發(fā)電壓（因此低負荷功率）。 一個大控制信號提供在高調(diào)速系統(tǒng)中，電容器收取的速率將要快得多。然后，可控硅將打開更長的周期，將提供更多

23、的能力來承擔(dān)負載。</p><p>　　電力電子技術(shù) Power Electronic Technology (II)</p><p><b>　　Part A </b></p><p>　　Thyristors </p><p>　　In the on-state of the thyristor, t he mai

24、n current flows from the anode to the cathode. In its</p><p>　　off-state, the thyristor can block a forward polarity voltage and not conduct.</p><p>　　The thyristor can be triggered into the on-

25、state by applying a pulse of positive gate current for a short duration provided that the device is in its forward blocking state. The forward voltage drop in the on-state is only a few volts (typically 1 to 3 V dependin

26、g on the device blocking voltage rating).</p><p>　　Once the device begins to conduct, it is latched on and the gate current can be removed. T he thyristor cannot be turned off by the gate, and the thyristor

27、conducts as a diode. Only when the anode current tries to go negative under the influence of the circuit in which the thyristor is</p><p>　　connected does the thyristor turn off and the current go to zero. T

28、his allows the gate to regain</p><p>　　control in order to turn the device on at some controllable time after it has again entered the</p><p>　　forward blocking state.</p><p>　　In r

29、everse bias at voltages below the reverse breakdown voltage, only a negligibly small</p><p>　　leakage current flows in the thyristor. Usually the thyristor voltage rating for forward and reverse blocking vol

30、tages are the same. Usually the thyristor voltage rating for forward and reverse blocking voltages are the same. Using the same arguments as for diodes, the thyristor can be represented by the idealized characteristics i

31、n analyzing converter topologies.</p><p>　　In an application of resistant load circuit, control can be exercised over the instant of current conduction during the positive half cycle of source voltage. When

32、the thyristor current tries to reverse itself when the source voltage goes negative, the idealized thyristor would have its current become zero immediately.</p><p>　　However, as specified in the thyristor da

33、ta sheets, the thyristor current reverses itself before</p><p>　　becoming zero. The important parameter is not the time it takes for the current to become zero</p><p>　　from its negative value,

34、but rather the turn-off time interval t q from the zero crossover of the</p><p>　　current to the zero crossover of the voltage across the thyristor. D uring t q a reverse voltage must bemaintained across the

35、 thyristor and only after this time is the device capable of blocking a forward voltage without going into its on-state.</p><p>　　If a forward voltage is applied to the thyristor before this interval has pas

36、sed, the device may prematurely turn on and damage to the device and circuit could result. Thyristor data sheets specify with a specified reverse voltage applied during this interval as well as a specified rate-of-rise o

37、f voltage beyond this interval. This interval is sometimes called the circuit-commutated-recovery time of the thyristor.</p><p>　　Depending on the application requirements, various types of thyristor are av

38、ailable. In</p><p>　　addition to voltage and current ratings, turn-off time , and the forward voltage drop, other</p><p>　　characteristics that must be considered include the rate-of-rise of the

39、 current (d i /d t ) at turn-on and the rate-of-rise of voltage (d u /d t ) at turn-off.</p><p>　　1. Phase-control thyristors. Sometimes termed converter thyristors, these are used primarily for rectifying l

40、ine-frequency voltage and current in applications such as phase-controlle drectifiers for dc and ac motor drives and in high-voltage dc power transmission. T he main device requirements are large voltage and current hand

41、ling capabilities and a low on-state voltage drop. T his type of thyristor has been produced in wafer diameters of up to 10 cm, where the average current is about 4000 A w</p><p>　　2. Inverter-grade thyristo

42、rs. T hese are designed to have small turn-off times t q in addition tolow on-state voltages, although on-state voltages are larger in devices with shorter values of t.T hese devices are available with ratings up to 2500

43、V and 1500A. Their turn-off times are usually in the range of a few microseconds to 100 μ s depending on their blocking voltage ratings and on-state voltage drops.</p><p>　　3. Light-activated thyristors. The

44、se can be triggered on by a pulse of light guided by optical fibers to a special sensitive region of the thyristor. The light-activated triggering of the thyristor uses the ability of light of appropriate wavelengths to

45、generate excess electron-hole pairs in the silicon. The primary use of these thyristors are in high-voltage applications such as high-voltage dc transmission where many thyristors are connected in series to make up a con

46、verter valve. Light-activa</p><p>　　There are other variations of these thyristors such as gate-assisted-turn-off thyristors (GATT),asymmetrical silicon-controlled-recrifiers (ASCR), and reverse-conducting-t

47、hyristors (RCT).T hese are utilized based on the application.</p><p><b>　　Part B</b></p><p>　　Power Integrated Circuits</p><p>　　Types of Power Integrated Circuits</

48、p><p>　　Modern semiconductor power control circuits have a considerable amount of control drive</p><p>　　circuitry in addition to the power device itself. The control circuitry often includes logic

49、 circuitrycontrolled by microprocessors. The inclusion of such control and drive circuitry on the same chipor wafer as the power device would greatly simplify the overall circuit design and broaden the range of potential

50、 applications. A cheaper and more reliable power control system would result from such integration. Overall, there would be a reduction in the complexity (fewer separate components) of cir</p><p>　　Such inte

51、gration has already been demonstrated in many applications. There are three classesof power integrated circuits including so-called smart or intelligent switches , high voltageintegrated circuits (HVICs), and discrete mo

52、dules. The domain of power integrated circuits,particularly smart switches and HVICs, is considered to be current levels less than 500-100 A andvoltages of approximately 1000 V or less. Discrete modules cover a much wide

53、r voltage-current range.</p><p>　　Smart switches are vertical power devices onto which additional components are added to theextent feasible without requiring major changes to the vertical power device proce

54、ss sequence.F eatures such as on-chip sensors for overcurrents and overtemperature as well as portions of drive circuits are examples of things that can be included. The pn junction formed from the N — drift region and t

55、he P-body region is always reverse biased if the drain of the vertical power MOSFET is positive with respec</p><p>　　High-voltage integrated circuits (HVICs) are made using conventional logic-level device<

56、;/p><p>　　fabrication process but with some modifications so that lateral high-voltage devices can also be</p><p>　　fabricated on the wafer compatibly with the low voltage devices. Two simple examp

57、les differ from each other in the manner in which electrical isolation between the various devices is realized.A ctual HVICs have considerably more complexity.</p><p>　　Discrete modules are composed of multi

58、ple chips mounted on a common insulating substrateand hermetically sealed into a single package. The various chips may include vertical powerdevices, a drive circuit chip, and a control circuit chip (perhaps even a PWM c

59、ontroller), andpossibly other functionality. Although this approach is not a completely integrated fabrication method, we include it because of its potential and its current widespread application compared to smart switc

60、hes or HVICs.</p><p>　　Challenges Facing PIC Commercial Commercialization</p><p>　　The use of power-integrated circuits in power electronics applications faces several</p><p>　　chal

61、lenges both technical and economic. T he technical issues include:</p><p>　　1. Electrical isolation of high-voltage components from low-voltage components.</p><p>　　2. Thermal management-power d

62、evices usually operate at higher temperatures thanlow-voltage devices.</p><p>　　3. On-chip interconnections with high-voltage conductor runs over low-voltage devices or</p><p>　　low-voltage regi

63、ons.</p><p>　　4. Fabrication process must provide full range of devices and components — transistors</p><p>　　(BJT, MOSFETs, IGBTs) diodes, resistors, capacitors, etc.</p><p>　　I n

64、addition, the use of power integrated circuits faces several economic issues. T hese include:</p><p>　　1. Large up-front development costs prior to any production runs.</p><p>　　2. Cost differen

65、tials between the three types of PICs.</p><p>　　3. Need for high volume applications to recover large development expenses.</p><p>　　Progress in Resolving Challenges</p><p>　　Isolat

66、ion of low-voltage devices from high-voltage elements, can be accomplished by either</p><p>　　dielectric isolation, pn junction isolation, or self-isolation. Dielectric isolation can be implemented in two wa

67、ys. The isolation basically consists of etching a pocket in the chip or wafer and then growing a layer of silicon dioxide in it. Next, a layer of silicon is deposited over the SiO 2 . After annealing the deposited silico

68、n at a high temperature, it becomes recrystallized and can then be used for fabricating the low-voltage devices. Dielectric isolation is free of parasitic devices such</p><p><b>　　Part C</b></

69、p><p>　　Silicon-Controlled Rectifier (SCR)</p><p>　　The SCR has become an important part of high-power electrical signal conditioning and</p><p>　　control. In some regards, it is a sol

70、id-state replacement for the relay, although there are some</p><p>　　problems if that analogy is taken too far. The standard diode is, in the ideal sense, a device that</p><p>　　will conduct cur

71、rent in only one direction. The SCR, again in the ideal sense, is like a diode thatwill not conduct in either direction until it is turned on or “ fired. ” Note the similarity to a diode,but with the added terminal, call

72、ed the gate . If the SCR is forward biased ( that is, positive voltageon the anode with respect to the cathode), it will not conduct. Now, suppose a voltage is placed onthe gate with respect to the cathode. There will be

73、 some positive value of this voltage — the t</p><p>　　Characteristics and specifications of SCRs are as follows.</p><p>　　1. Maximum forward current. There is a maximum current that the SCR can

74、carry in the</p><p>　　forward direction without damage. This value varies from a few hundred milliamps to</p><p>　　more than a thousand amps, for large industrial types.</p><p>　　2.

75、 Peak reverse voltage. Like a diode, there is a perk reverse-bias voltage that can be</p><p>　　applied to the SCR without damage. The value varies from a few volts to several</p><p>　　thousand v

76、olts.</p><p>　　3. Trigger voltage. The minimum gate voltage to drive the SCR into conduction varies</p><p>　　between types and sizes, from a few volts to 40 V.</p><p>　　4. Trigger c

77、urrent. There is a minimum current that the source of trigger voltage must be</p><p>　　able to provide before the SCR can be fired. This varies from a few milliamps to several</p><p>　　hundred m

78、illiamps.</p><p>　　5. Holding current . This refers to the minimum anode-to-cathode current necessary to</p><p>　　keep the SCR conducting in the forward-conducting state. The value varies from 2

79、0 to</p><p><b>　　100 mA.</b></p><p>　　AC Operation</p><p>　　The operation of an SCR varies in the rms dc voltage in half-wave operation. The trigger</p><p>

80、;　　voltage is developed by some circuit that produces a pulse at a certain selected phase of the</p><p>　　applied ac signal. Thus, the SCR turns on in a repetitive fashion as shown. The SCR is turned back of

81、f, of course, in each half cycle when the ac polarity reverses. By changing the part of the positive half cycle when the trigger is applied, the effective (rms) value of dc voltage applied to the load can be increased. O

82、f course, with this circuit the maximum possible rms dc voltage is that which would be developed by a half-wave rectifier. If more power is required, the SCR can be used with a fu</p><p>　　Trigger Control &l

83、t;/p><p>　　To use the SCR in process-control applications, special circuitry to convert control signalsinto suitable trigger signals to the SCRs is required. These circuits are usually composed ofelectronic sys

84、tems that use the control voltage to determine the phase of the ac load voltage atwhich the SCR should be turned on.</p><p>　　The control-signal voltage is used to provide base drive to a transistor via an L

85、ED that</p><p>　　ensures isolation of the control circuit from the power circuit. At low-base drive the capacitor is</p><p>　　charged slowly, and will not reach the SCR trigger voltage until lat

86、e in the cycle (hence low load power).</p><p>　　A large control signal will provide high base drive, and the capacitor will charge much more quickly. Then the SCR will turn on much earlier in the cycle, and