逆變器外文文獻(xiàn)及翻譯

1、Inverter1 IntroductionAn inverter is an electrical device that converts direct current (DC) to alternating current (AC); the converted AC can be at any required voltage and frequency with the use of appropriate transformers, switching, and control circuits.Solid-state inverters have no moving parts

2、and are used in a wide range of applications, from small switching power supplies in computers, to large electric utility high-voltage direct current applications that transport bulk power. Inverters are commonly used to supply AC power from DC sources such as solar panels or batteries.There are two

3、 main types of inverter. The output of a modified sine wave inverter is similar to a squarewave output except that the output goes to zero volts for a time before switching positive or negative. It is simple and low cost and is compatible with most electronic devices, except for sensitive or special

4、ized equipment, for example certain laser printers. A pure sine wave inverter produces a nearly perfect sine wave output (<3% total harmonic distortion) that is essentially the same as utility-supplied grid power. Thus it is compatible with all AC electronic devices. This is the type used in grid

5、-tie inverters. Its design is more complex, and costs 5 or 10 times more per unit power The electrical inverter is a high-power electronic oscillator. It is so named because early mechanical AC to DC converters were made to work in reverse, and thus were "inverted", to convert DC to AC.The

6、 inverter performs the opposite function of a rectifier.2 Applications2.1 DC power source utilizationAn inverter converts the DC electricity from sources such as batteries, solar panels, or fuel cells to AC electricity. The electricity can be at any required voltage; in particular it can operate AC

7、equipment designed for mains operation, or rectified to produce DC at any desired voltageGrid tie inverters can feed energy back into the distribution network because they produce alternating current with the same wave shape and frequency as supplied by the distribution system. They can also switch

8、off automatically in the event of a blackout.Micro-inverters convert direct current from individual solar panels into alternating current for the electric grid. They are grid tie designs by default.2.2 Uninterruptible power suppliesAn uninterruptible power supply (UPS) uses batteries and an inverter

9、 to supply AC power when main power is not available. When main power is restored, a rectifier supplies DC power to recharge the batteries.2.3 Induction heatingInverters convert low frequency main AC power to a higher frequency for use in induction heating. To do this, AC power is first rectified to

10、 provide DC power. The inverter then changes the DC power to high frequency AC power.2.4 HVDC power transmissionWith HVDC power transmission, AC power is rectified and high voltage DC power is transmitted to another location. At the receiving location, an inverter in a static inverter plant converts

11、 the power back to AC.2.5 Variable-frequency drivesA variable-frequency drive controls the operating speed of an AC motor by controlling the frequency and voltage of the power supplied to the motor. An inverter provides the controlled power. In most cases, the variable-frequency drive includes a rec

12、tifier so that DC power for the inverter can be provided from main AC power. Since an inverter is the key component, variable-frequency drives are sometimes called inverter drives or just inverters.2.6 Electric vehicle drivesAdjustable speed motor control inverters are currently used to power the tr

13、action motors in some electric and diesel-electric rail vehicles as well as some battery electric vehicles and hybrid electric highway vehicles such as the Toyota Prius and Fisker Karma. Various improvements in inverter technology are being developed specifically for electric vehicle applications. 2

14、 In vehicles with regenerative braking, the inverter also takes power from the motor (now acting as a generator) and stores it in the batteries.2.7 The general caseA transformer allows AC power to be converted to any desired voltage, but at the same frequency. Inverters, plus rectifiers for DC, can

15、be designed to convert from any voltage, AC or DC, to any other voltage, also AC or DC, at any desired frequency. The output power can never exceed the input power, but efficiencies can be high, with a small proportion of the power dissipated as waste heat.3 Circuit description3.1 Basic designsIn on

16、e simple inverter circuit, DC power is connected to a transformer through the centre tap of the primary winding. A switch is rapidly switched back and forth to allow current to flow back to the DC source following two alternate paths through one end of the primary winding and then the other. The alt

17、ernation of the direction of current in the primary winding of the transformer produces alternating current (AC) in the secondary circuit.The electromechanical version of the switching device includes two stationary contacts and a spring supported moving contact. The spring holds the movable contact

18、 against one of the stationary contacts and an electromagnet pulls the movable contact to the opposite stationary contact. The current in the electromagnet is interrupted by the action of the switch so that the switch continually switches rapidly back and forth. This type of electromechanical invert

19、er switch, called a vibrator or buzzer, was once used in vacuum tube automobile radios. A similar mechanism has been used in door bells, buzzers and tattoo guns.As they became available with adequate power ratings, transistors and various other types of semiconductor switches have been incorporated

20、into inverter circuit designs3.2 Output waveformsThe switch in the simple inverter described above, when not coupled to an output transformer, produces a square voltage waveform due to its simple off and on nature as opposed to the sinusoidal waveform that is the usual waveform of an AC power supply

21、. Using Fourier analysis, periodic waveforms are represented as the sum of an infinite series of sine waves. The sine wave that has the same frequency as the original waveform is called the fundamental component. The other sine waves, called harmonics, that are included in the series have frequencie

22、s that are integral multiples of the fundamental frequency.The quality of output waveform that is needed from an inverter depends on the characteristics of the connected load. Some loads need a nearly perfect sine wave voltage supply in order to work properly. Other loads may work quite well with a

23、square wave voltage.3.3 Three phase invertersThree-phase inverters are used for variable-frequency drive applications and for high power applications such as HVDC power transmission. A basic three-phase inverter consists of three single-phase inverter switches each connected to one of the three load

24、 terminals. For the most basic control scheme, the operation of the three switches is coordinated so that one switch operates at each 60 degree point of the fundamental output waveform. This creates a line-to-line output waveform that has six steps. The six-step waveform has a zero-voltage step betw

25、een the positive and negative sections of the square-wave such that the harmonics that are multiples of three are eliminated as described above. When carrier-based PWM techniques are applied to six-step waveforms, the basic overall shape, or envelope, of the waveform is retained so that the 3rd harm

26、onic and its multiples are cancelled4 History4.1 Early invertersFrom the late nineteenth century through the middle of the twentieth century, DC-to-AC power conversion was accomplished using rotary converters or motor-generator sets (M-G sets). In the early twentieth century, vacuum tubes and gas fi

27、lled tubes began to be used as switches in inverter circuits. The most widely used type of tube was the thyratron.The origins of electromechanical inverters explain the source of the term inverter. Early AC-to-DC converters used an induction or synchronous AC motor direct-connected to a generator (d

28、ynamo) so that the generator's commutator reversed its connections at exactly the right moments to produce DC. A later development is the synchronous converter, in which the motor and generator windings are combined into one armature, with slip rings at one end and a commutator at the other and

29、only one field frame. The result with either is AC-in, DC-out. With an M-G set, the DC can be considered to be separately generated from the AC; with a synchronous converter, in a certain sense it can be considered to be "mechanically rectified AC". Given the right auxiliary and control eq

30、uipment, an M-G set or rotary converter can be "run backwards", converting DC to AC. Hence an inverter is an inverted converter.4.2 Controlled rectifier invertersSince early transistors were not available with sufficient voltage and current ratings for most inverter applications, it was th

31、e 1957 introduction of the thyristor or silicon-controlled rectifier (SCR) that initiated the transition to solid state inverter circuits.The commutation requirements of SCRs are a key consideration in SCR circuit designs. SCRs do not turn off or commutate automatically when the gate control signal

32、is shut off. They only turn off when the forward current is reduced to below the minimum holding current, which varies with each kind of SCR, through some external process. For SCRs connected to an AC power source, commutation occurs naturally every time the polarity of the source voltage reverses.

33、SCRs connected to a DC power source usually require a means of forced commutation that forces the current to zero when commutation is required. The least complicated SCR circuits employ natural commutation rather than forced commutation. With the addition of forced commutation circuits, SCRs have be

34、en used in the types of inverterIn applications where inverters transfer power from a DC power circuits described above.source to an AC power source, it is possible to use AC-to-DC controlled rectifier circuits operating in the inversion mode. In the inversion mode, a controlled rectifier circuit op

35、erates as a line commutated inverter. This type of operation can be used in HVDC power transmission systems and in regenerative braking operation of motor control systems.Another type of SCR inverter circuit is the current source input (CSI) inverter. A CSI inverter is the dual of a six-step voltage

36、 source inverter. With a current source inverter, the DC power supply is configured as a current source rather than a voltage source. The inverter SCRs are switched in a six-step sequence to direct the current to a three-phase AC load as a stepped current waveform. CSI inverter commutation methods i

37、nclude load commutation and parallel capacitor commutation. With both methods, the input current regulation assists the commutation. With load commutation, the load is a synchronous motor operated at a leading power factor. As they have become available in higher voltage and current ratings, semicon

38、ductors such as transistors or IGBTs that can be turned off by means of control signals have become the preferred switching components for use in inverter circuits.4.3 Rectifier and inverter pulse numbersRectifier circuits are often classified by the number of current pulses that flow to the DC side

39、 of the rectifier per cycle of AC input voltage. A single-phase half-wave rectifier is a one-pulse circuit and a single-phase full-wave rectifier is a two-pulse circuit. A three-phase half-wave rectifier is a three-pulse circuit and a three-phase full-wave rectifier is a six-pulse circuit。 With thre

40、e-phase rectifiers, two or more rectifiers are sometimes connected in series or parallel to obtain higher voltage or current ratings. The rectifier inputs are supplied from special transformers that provide phase shifted outputs. This has the effect of phase multiplication. Six phases are obtained f

41、rom two transformers, twelve phases from three transformers and so on. The associated rectifier circuits are 12-pulse rectifiers, 18-pulse rectifiers and so on. When controlled rectifier circuits are operated in the inversion mode, they would be classified by pulse number also. Rectifier circuits th

42、at have a higher pulse number have reduced harmonic content in the AC input current and reduced ripple in the DC output voltage. In the inversion mode, circuits that have a higher pulse number have lower harmonic content in the AC output voltage waveform.11逆變器1 簡(jiǎn)介逆變器是一種能將直流電轉(zhuǎn)化為可變的交流電的電子裝置，使用適當(dāng)?shù)淖儔浩?、開

43、關(guān)以及控制電路可以將轉(zhuǎn)化的交流電調(diào)整到任何需要的電壓以及頻率值。固定的逆變器沒有移動(dòng)部件，其應(yīng)用范圍極其廣泛，從小型計(jì)算機(jī)開關(guān)電源，到大型電力公司高壓直流電源應(yīng)用，運(yùn)輸散貨。逆變器通常用于提供從諸如太陽能電池板或電池直流電源轉(zhuǎn)換的交流電源.逆變器有兩種主要類型。對(duì)修改后正弦波逆變器輸出是一個(gè)類似方波輸出，輸出去除了一時(shí)間為零伏特，然后才轉(zhuǎn)到正或負(fù)。它的電路簡(jiǎn)單而且成本一般較低，并與大多數(shù)電子設(shè)備兼容，除了敏感或?qū)Ｓ迷O(shè)備，例如某些激光打印機(jī)。純正弦波逆變器產(chǎn)生一個(gè)近乎完美的正弦波輸出“（<3的總諧波失真），它本質(zhì)上與公用事業(yè)電網(wǎng)提供的相同。因此它與所有的交流電子設(shè)備兼容。這是網(wǎng)逆變器配合使

44、用的類型。它的設(shè)計(jì)更為復(fù)雜，成本5 人以上每單位功率。1 電逆變器是一種高功率電子振蕩器的10倍。它是如此命名是因?yàn)樵缙跈C(jī)械A(chǔ)C到DC專換器的工作作了相反，因此是“倒“，轉(zhuǎn)換成直流到交流。變頻器的整流執(zhí)行相反的功能2 應(yīng)用2.1 直流電源利用率逆變器將直流電，如電池，太陽能電池板，燃料電池等轉(zhuǎn)換為交流電直流電。轉(zhuǎn)換的交流電可以是任意需要大小的交流電，特別是它可以操作交流設(shè)備用于電源操作，或者濾波產(chǎn)生任何需要的直流電壓。配電網(wǎng)絡(luò)逆變器可以將能量反饋到分配網(wǎng)絡(luò)，因?yàn)樗麄儺a(chǎn)生的交流電和分配網(wǎng)絡(luò)提供的交流電的波形和頻率可以是一樣的。而且他們也可以自動(dòng)關(guān)斷輸出當(dāng)遇到停電事故時(shí)。微型逆變器將由個(gè)人太陽能電

45、池板產(chǎn)生的直流電轉(zhuǎn)化為交流電并入電網(wǎng)。接從個(gè)人的太陽能電池板的電流。它們使用默認(rèn)的輸電網(wǎng)設(shè)計(jì)。2.2 不間斷電源不間斷電源（UPS當(dāng)主電源無法使用時(shí)使用電池和逆變器提供交流電源。當(dāng)主電源恢復(fù)時(shí)，一個(gè)整流器供應(yīng)直流電源對(duì)電池進(jìn)行充電。2.3 感應(yīng)加熱逆變器將低頻交流電源轉(zhuǎn)化為更高的頻率以用于感應(yīng)加熱使用。要做到這一點(diǎn)，首先交流電源經(jīng)過濾波提供直流電源。該逆變器，然后更改為高頻率的交流電源直流電源。2.4 高壓直流輸電隨著高壓直流輸電，交流電源進(jìn)行整流和高壓直流電源被傳輸?shù)搅硪粋€(gè)位置。在接收的位置，在一個(gè)靜止變流器廠將直流電源轉(zhuǎn)換回交流電2.5 變頻驅(qū)動(dòng)器一個(gè)變頻驅(qū)動(dòng)控制器通過控制供應(yīng)給電機(jī)的電源

46、電壓和頻率來控制交流電機(jī)的運(yùn)行速度。逆變器提供控制信號(hào)。在大多數(shù)情況下，變頻驅(qū)動(dòng)器包括一個(gè)整流器，因而提供給逆變器的直流電源可以由交流主電源提供。由于逆變器是關(guān)鍵部件，變頻驅(qū)動(dòng)器有時(shí)也被稱為逆變器驅(qū)動(dòng)器或只是逆變器2.6 電動(dòng)汽車驅(qū)動(dòng)調(diào)速電動(dòng)機(jī)控制逆變器是目前用于電力牽引在一些電動(dòng)和柴油電動(dòng)軌道車輛以及一些電池電動(dòng)汽車上的電機(jī)，如豐田 Prius 和菲斯克噶瑪混合動(dòng)力電動(dòng)汽車高速公路交通工具。在變頻技術(shù)的各項(xiàng)改善措施正在制定專門針對(duì)電動(dòng)車輛的應(yīng)用。與更新制動(dòng)車輛，還需要從變頻器的電機(jī)（現(xiàn)在作為發(fā)電機(jī)）和它儲(chǔ)存在電池里的電源。2.7 一般情況下一個(gè)變壓器允許交流電源被轉(zhuǎn)換為任何所需的電壓，但是卻

47、在相同的頻率。逆變器，直流加整流器，可以設(shè)計(jì)成任何轉(zhuǎn)換電壓，交流或直流，在任何需要的頻率，以任何其他電壓，也可以是交流或直流。輸出功率不能超過輸入功率，但效率可以很高，可以允許作為一部分余熱消耗掉功率很小的一部分。3 電路描述3.1 基本設(shè)計(jì)在一個(gè)簡(jiǎn)單的逆變電路中，直流電源通過初級(jí)繞組的中心抽頭連接到變壓器。開關(guān)以極高的頻率來回切換，使電流回流在變壓器的初級(jí)繞組里流過一個(gè)方向后再向另一個(gè)方向流動(dòng)。初級(jí)繞組里電流方向的變化通過變壓器在次級(jí)繞組里產(chǎn)生交變電流。彈簧持有一個(gè)可移在開關(guān)設(shè)備機(jī)電版本包括兩個(gè)固定觸點(diǎn)和彈簧支撐移動(dòng)接觸點(diǎn)。動(dòng)的觸體來和固定觸點(diǎn)接觸，電磁鐵拉動(dòng)可移動(dòng)的觸體到對(duì)面的固定的觸體。

48、在電磁鐵的電流中斷的交換機(jī)中，使交換開關(guān)不斷來回迅速切換迅速。這種機(jī)動(dòng)逆變器式開關(guān)，稱為一個(gè)振動(dòng)器或蜂鳴器，曾經(jīng)在真空電子管汽車收音機(jī)中使用。一個(gè)類似的電子裝置已用于門鈴，蜂鳴器和紋身槍。當(dāng)開關(guān)管有有足夠的額定功率，晶體管和半導(dǎo)體開關(guān)各種其他類型的的電子開關(guān)器件可用已納入逆變器電路設(shè)計(jì)。3.2 輸出波形上述簡(jiǎn)單的逆變器中的開關(guān)，當(dāng)不耦合到輸出變壓器時(shí)，輸出電壓波形由于開關(guān)管簡(jiǎn)單的導(dǎo)通或關(guān)斷產(chǎn)生一個(gè)方波電壓輸出，而不是交流電最常見的正弦波形，它是一個(gè)AC電源波形通常由于其簡(jiǎn)單。利用傅里葉分析，周期性波形表示為一個(gè)無窮級(jí)數(shù)的正弦波的總和。正弦波中和原始波形具有相同的頻率的波稱為基波。其他頻率的正弦波，稱為諧波，這是該系列中包括有頻率是基波頻率的整數(shù)倍。輸出波形是從一個(gè)逆變器所需的質(zhì)量取決于逆變器所連接的負(fù)載特性。一些載入需要一個(gè)近乎完美的正弦波電壓供應(yīng)才能正常