完整版逆變器外文文獻(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 o With thr

40、ee-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

41、from 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 t

42、hat 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.逆變器1簡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 關(guān)

43、以及限制電路可以將轉(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部件,其應(yīng)用范圍極其廣泛,從小型計算機(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.對修改后正弦波逆變器輸出是一個類似方波輸出,輸出去除了 一時間為零伏特,然后才轉(zhuǎn)到正或負(fù).它的電路簡單而且本錢一般較低,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).純粹弦波逆變器產(chǎn)生一個近 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)計更為復(fù)雜, 本錢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 名是由于早期機(jī)械A(chǔ)C到D次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響到分配網(wǎng)絡(luò),由于他們產(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關(guān)斷輸出當(dāng)遇到停電事故 時.微型逆變器將由個

45、人太陽能電池板產(chǎn)生的直流電轉(zhuǎn)化為交流電并入電網(wǎng).接從個人 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.2.2 不間斷電源不問斷電源UPS當(dāng)主電源無法使用時使用電池和逆變器提供交流電源.當(dāng)主電 源恢復(fù)時,一個整流器供應(yīng)直流電源對電池進(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,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€位置.在接收的 位置,在一個靜止變流器廠將直流電源轉(zhuǎn)換回交流電2.5 變頻驅(qū)動器一個變頻驅(qū)動限制器通過限制

46、供應(yīng)給電機(jī)的電源電壓和頻率來限制交流電機(jī)的運行速度.逆變器提供限制信號.在大多數(shù)情況下,變頻驅(qū)動器包括一個整流器,因而提供應(yīng) 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)動器有時也 被稱為逆變器驅(qū)動器或只是逆變器2.6 電動汽車驅(qū)動調(diào)速電動機(jī)限制逆變器是目前用于電力牽引在一些電動和柴油電動軌道車輛以及一些電池電動汽車上的電機(jī),如豐田Prius和菲斯克喝瑪混合動力電動汽車高速公路交 通工具.在變頻技術(shù)的各項改善舉措正在制定專門針對電動車輛的應(yīng)用.與更新制動車 輛,還需要從變頻器的電機(jī)現(xiàn)在作為發(fā)電機(jī)和它儲存在電池里的電源.2.7 一般情況下一個變壓器允許交流電源被轉(zhuǎn)換為任何所

47、需的電壓, 但是卻在相同的頻率.逆變器, 直流加整流器,可以設(shè)計成任何轉(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 許作為一局部余熱消耗掉功率很小的一局部.3電路描述3.1根本設(shè)計在一個簡單的逆變電路中,直流電源通過初級繞組的中央抽頭連接到變壓器.開關(guān) 以極高的頻率往返切換,使電流回流在變壓器的初級繞組里流過一個方向后再向另一個 方向流動.初級繞組里電流方向的變化通過變壓器在次級繞組里產(chǎn)生交變電流.在開關(guān)設(shè)備機(jī)電版本包括兩個固定觸點和彈簧支撐移動接觸點彈簧持有一個可移 動的觸體來和固定觸點接觸,電磁鐵拉動可移動的

48、觸體到對面的固定的觸體.在電磁鐵 的電流中斷的交換機(jī)中,使交換開關(guān)不斷往返迅速切換迅速.這種機(jī)動逆變器式開關(guān), 稱為一個振動器或蜂鳴器,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.3.2 輸出波形上述簡單的逆變器中的開關(guān),當(dāng)不耦合到輸出變壓器時,輸出電壓波形由于開關(guān)管簡單 的導(dǎo)通或關(guān)斷產(chǎn)生一個方波電壓輸出,而不是交流電最常見的正弦波形,它是一個 AC 電源波形通常由于其簡單.利用傅里葉分析,周期性波形表示為一個無窮級數(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.一些載入需要一個近乎完美的正弦波電壓供應(yīng)才能正常工作. 其他的負(fù)載可能使用方