電氣專業(yè)畢業(yè)設(shè)計(jì)外文翻譯--光伏陣列和逆變器

1、<p><b>　　附錄一： 中文翻譯</b></p><p><b>　　光伏陣列和逆變器</b></p><p>　　摘要-本文提出了一種雙向電子轉(zhuǎn)換器，這兩項(xiàng)措施的特性曲線光伏發(fā)電機(jī)和物理模擬其實(shí)時(shí)物理行為。這兩個(gè)轉(zhuǎn)換器的運(yùn)行模式（模擬和測(cè)量）可以用微控制器實(shí)施其數(shù)字化。該轉(zhuǎn)換器的電流控制的手段，是通過(guò)一個(gè)類比變滯后控制回路，其范

2、圍是由微控制器提供。在測(cè)量作業(yè)模式中，數(shù)字電壓控制回路的實(shí)施，使光伏發(fā)電支付其四特性曲線。在模擬運(yùn)行模式中，測(cè)量的電壓和電流范圍是從編程計(jì)算或衡量四特性曲線。</p><p>　　該系統(tǒng)每秒可以測(cè)量三次7光伏發(fā)電機(jī)的特性曲線，然后效仿其電氣性能測(cè)試的光伏逆變器。分析光伏發(fā)電機(jī)和逆變器，不但可以可靠地運(yùn)行，其結(jié)果可以幫助他們更好地工作。</p><p>　　比較它們的性能以及在實(shí)現(xiàn)最佳配置上

3、， 仿真和實(shí)驗(yàn)結(jié)果都非常令人滿意。</p><p><b>　　1 導(dǎo)言</b></p><p>　　完整的表征光伏陣列和逆變器，尤其是在不同操作條件下，采用光伏系統(tǒng)是一個(gè)非常重要的方面。對(duì)于光伏陣列，實(shí)驗(yàn)室中使用不同的設(shè)備，以獲取他們的I - V特性曲線。關(guān)于光伏逆變器，各種實(shí)時(shí)模擬器已經(jīng)被提出來(lái)在不同操作條件下用于測(cè)試逆變器。</p>

4、<p>　　然而，在一段時(shí)間內(nèi)實(shí)驗(yàn)室里的所有這些系統(tǒng)都無(wú)法“保存”幾個(gè)光伏發(fā)電機(jī)的四特性曲線的實(shí)時(shí)演變，從而“仿造”它提供一個(gè)變頻器。這些優(yōu)化設(shè)計(jì)的設(shè)備和光伏系統(tǒng)的配置顯示出的特征結(jié)果是非常有趣的。通過(guò)測(cè)量四特性曲線在一段時(shí)間內(nèi)的不同光伏陣列，可以從已知的能源里獲得最大值，這是可以用整個(gè)光伏發(fā)電機(jī)計(jì)算的最高能量。一旦獲得這一信息，就有可能確定出一個(gè)系統(tǒng)的配置功能（系列/并行方面，中環(huán)/字符串轉(zhuǎn)換器等）消耗的總能量 ，然后這個(gè)

5、能源與可以從整個(gè)光伏發(fā)電機(jī)獲得的最大能源相比?？傊?，不同配置的系統(tǒng)可以進(jìn)行比較，然后從能源的角度可以確定一個(gè)最理想的。</p><p>　　另一方面，一個(gè)分析在不同的現(xiàn)實(shí)條件下實(shí)現(xiàn)最大功率點(diǎn)跟蹤（最大功率跟蹤）技術(shù)的文獻(xiàn)提出一個(gè)仿真器復(fù)制這些實(shí)時(shí)的I - V特性曲線是可行的。此外，在實(shí)驗(yàn)室里這個(gè)模擬器可以進(jìn)行分析的行為，在特殊條件下（局部陰影，黎明，黃昏等）最大功率跟蹤技術(shù)和完整的光伏發(fā)電系統(tǒng)沒(méi)有必要進(jìn)行實(shí)地試驗(yàn)

6、，特別是等待大氣條件。實(shí)驗(yàn)室里，在沒(méi)有真正的光伏能源的條件下，光伏發(fā)電機(jī)的電氣性能仿真允許光伏逆變器進(jìn)行性能分析。</p><p>　　上一段描述的電子轉(zhuǎn)換器有兩個(gè)操作模式。其主要優(yōu)勢(shì)是擬議轉(zhuǎn)換器是把其性能和運(yùn)作模式結(jié)合起來(lái)的唯一設(shè)備：特性曲線測(cè)量作業(yè)模式允許獲得光電發(fā)生器的電壓和電流的轉(zhuǎn)變模式，在實(shí)驗(yàn)室里，這一模式就可以用于測(cè)試任何變頻器。因此，這個(gè)逆變器將通過(guò)一個(gè)相當(dāng)可靠的光伏電壓的電力仿真行為被測(cè)試，在實(shí)際

7、運(yùn)行條件下其性能將獲得一個(gè)非常高的精度。</p><p>　　設(shè)計(jì)和建造一個(gè)15千瓦的樣機(jī)，在測(cè)量作業(yè)模式中，這個(gè)原型可以每秒同時(shí)衡量三次7種不同的光伏發(fā)電機(jī)的特性曲線。就像將要顯示的一樣，實(shí)驗(yàn)測(cè)試取得了令人滿意的成果。在模擬操作模式中，原型可以仿效最高電壓和電流為500 V和30A的光伏發(fā)電機(jī)的行為，并分別提供了一個(gè)最大為15千瓦的功率。</p><p><b>　　2 系統(tǒng)的

8、提議描述</b></p><p>　　系統(tǒng)的提議方案如圖1 ，它主要由顯示在圖片中央的電子轉(zhuǎn)換器，顯示在光伏發(fā)電機(jī)左側(cè)的微控制器和顯示在右側(cè)逆變器組成。</p><p>　　圖1 模擬仿真測(cè)試系統(tǒng)</p><p>　　15千瓦的實(shí)驗(yàn)電子轉(zhuǎn)換原型是系統(tǒng)的的核心。其目前的控制手段是通過(guò)內(nèi)部類比控制回路實(shí)現(xiàn)的。同時(shí)包括帶有電壓和電流傳感器的測(cè)量板和轉(zhuǎn)換器。針對(duì)

9、過(guò)電壓和過(guò)電流，該轉(zhuǎn)換器包括若干電子對(duì)其防御。</p><p>　　電子轉(zhuǎn)換器能夠在測(cè)量和仿真這兩種不同的模式下運(yùn)行。這兩種運(yùn)行模式是通過(guò)集成在一臺(tái)PC的DSP微控制器驅(qū)動(dòng)的。</p><p>　　在測(cè)量操作模式中，該設(shè)備與7種不同的光伏發(fā)電機(jī)的最大值相連接。數(shù)字電壓控制回路是在微控制器編程以后，使光伏發(fā)電覆蓋其完整的I - V特性曲線。電壓控制回路為內(nèi)部電流環(huán)提供了參考。然后每秒三次連續(xù)

10、測(cè)量其特性曲線。獲得的數(shù)據(jù)都儲(chǔ)存在個(gè)人電腦，為后面的分析做準(zhǔn)備，還用于為模擬操作模式產(chǎn)生電流電壓模式。電腦還可以用來(lái)對(duì)四特性曲線進(jìn)行實(shí)時(shí)監(jiān)測(cè)。</p><p>　　在模擬操作模式下，被測(cè)試的逆變器連接到轉(zhuǎn)換器和微控制器從理想電流電壓模式產(chǎn)生參考電流，這是通過(guò)測(cè)量四特性曲線特定光伏發(fā)電機(jī)演變獲得的。這樣，無(wú)論是直接通過(guò)微控制器編程或通過(guò)前測(cè)量測(cè)量操作模式獲得，設(shè)備都可以作為任何電力陣列性能的實(shí)時(shí)仿真器。因此，光伏逆

11、變性能和效率以及表征任何最大功率跟蹤算法可以可靠地，準(zhǔn)確地被執(zhí)行。</p><p>　　正如介紹中所說(shuō)，設(shè)備可以仿效光電發(fā)電機(jī)的性能，最高可以達(dá)到15千瓦，最大短路電流和開(kāi)路電壓分別可以達(dá)到30安和500伏。</p><p>　　圖2顯示了變換器的結(jié)構(gòu)。從圖中可以看出，它是由一個(gè)雙向DC / DC轉(zhuǎn)換器以及過(guò)濾階段和能量耗散電路組成的。</p><p>　　圖2 電

12、子轉(zhuǎn)換器的結(jié)構(gòu)</p><p>　　該轉(zhuǎn)換器由兩個(gè)IGBT，T1和T2 ，以及兩個(gè)二極管D1、D2組成，是由一項(xiàng)糾正交流三相電壓源提供電流的。轉(zhuǎn)換器的輸出主要由允許短期和開(kāi)路作業(yè)的電感L和電容C1和C2 組成。過(guò)濾器的其他部分是根據(jù)減輕切換諧波，同時(shí)能消除諧振模式，并盡量減少損失的目的設(shè)計(jì)的。</p><p>　　在模擬操作模式下，該轉(zhuǎn)換器成為一個(gè)由交流電壓提供的勃克穆利糾正所。在這種情況

13、下，能源從AC源傳輸?shù)搅诉B接到輸出擬議轉(zhuǎn)換的光伏逆變器。為了使轉(zhuǎn)換器效仿光伏發(fā)電機(jī)的性能，測(cè)量輸出電壓被發(fā)送到外部微控制器（ DSP ），控制器的作用是計(jì)算從編好的I-V特性曲線中由轉(zhuǎn)換器收集的電流 。</p><p>　　如圖3所示，電感L中的電流IL由變滯環(huán)電流控制回路來(lái)控制。這個(gè)控制回路可以實(shí)現(xiàn)短路操作，這樣就可以測(cè)量和仿真光伏陣列。轉(zhuǎn)換器的輸出過(guò)濾器基本不影響動(dòng)態(tài)電流控制環(huán)路，因?yàn)檫^(guò)濾器是用來(lái)過(guò)濾頻率遠(yuǎn)高

14、于控制回路所需的切換諧波?？傊?，除了快速的輸出電壓變化，轉(zhuǎn)換器的輸出電流實(shí)際上和電感器中的電流相等。</p><p>　　在測(cè)量作業(yè)模式下，轉(zhuǎn)換器由光電發(fā)電器提供能量驅(qū)動(dòng)。光電發(fā)電器的能量在耗散電路中消散。這個(gè)耗散電路包括一個(gè)IGBT的T3，二極管 D3 ，和耗散電阻R。在這種工作模式下，通過(guò)轉(zhuǎn)換器，光電發(fā)電器可以完整地作出伏安特性曲線。</p><p>　　原則上，可以用兩種方法來(lái)概括光

15、電發(fā)電器的特性曲線。一個(gè)是以電流為軸，一個(gè)是以電壓為軸。然而，從伏安特性曲線的外形來(lái)看，很明顯用第二種方法會(huì)得到更好的結(jié)果，因?yàn)榈谝环N方法所得到的斜坡遠(yuǎn)高于第二種方法所得到的斜坡。由此我們可以得出一個(gè)結(jié)論：轉(zhuǎn)換器的輸出電壓必須受到控制，而且要斷路、短路時(shí)的參考點(diǎn)不同。</p><p><b>　　附錄二： 外文原文</b></p><p>　　The Analysis

16、 of Photovoltaic Arrays and Inverters</p><p>　　Abstract - This paper proposes a bi-directional electronic converter that both measures the characteristic curves of photovoltaic generators and physically emul

17、ates their real-time physical behavior. The two converter operation modes (emulation and measurement) are digitally implemented in a microcontroller. The converter current is controlled by means of an analogical variable

18、-hysteresis control loop, whose reference is provided by the microcontroller. In the measuring operation mode, a digital</p><p>　　The system can measure three times per second the characteristic curves of up

19、 to seven photovoltaic generators and then emulate their electrical behavior to test photovoltaic inverters. Analysis of photovoltaic generators and inverters can thus be reliably carried out, and the results can help to

20、 both</p><p>　　compare their performance and achieve optimal configurations.</p><p>　　Simulation and experimental results are very satisfactory.</p><p>　　I. INTRODUCTION</p>

21、<p>　　The complete characterization of photovoltaic arrays and inverters, specially their performance under different operating conditions, is a very important aspect in photovoltaic systems. In the case of photovo

22、ltaic arrays, different equipments are used in the laboratories to obtain their I- V characteristic curves. Concerning the photovoltaic inverters, a variety of real-time simulators have been proposed to test the inverter

23、s under different operating conditions.</p><p>　　However, all these systems are not able to both “save” the real-time evolution of the I-V characteristic curves of several photovoltaic generators during a pe

24、riod of time, and then “reproduce” it to supply an inverter at the laboratory. An equipment with these characteristics results to be very interesting for an optimum design and configuration of the photovoltaic systems. B

25、y measuring the I-V characteristic curves of different photovoltaic arrays during a period of time, the maximum available </p><p>　　On the other hand, with an emulator that can reproduce in real time these I

26、- V characteristic curves, a reliable analysis in real conditions of the different maximum power point tracking (MPPT) techniques proposed in the literature can be carried out. In addition, with this emulator it is possi

27、ble to analyze at the laboratory the behavior of both the MPPT techniques and the complete photovoltaic system under special conditions (partial shading, dawn, nightfall, etc.) with no need to make field t</p><

28、;p>　　In this paper, an electronic converter is proposed that has the two operation modes described in the previous paragraph. The main advantage of the proposed converter is its ability to combine both operation modes

29、 in an only equipment: the characteristic curves measuring operation mode permits to obtain a pattern for the evolution of the voltage and current of the photovoltaic generator, and this pattern can then be used to test

30、any inverter at the laboratory. This inverter will be tested, theref</p><p>　　A 15 kW prototype has been designed and built. In the measuring operation mode, this prototype can measure simultaneously three t

31、imes per second the characteristic curves of 7 different photovoltaic generators. Experimental tests have achieved satisfactory results, as will be exposed later. In the emulating operation mode, the prototype can emulat

32、e the behavior of a photovoltaic generator with maximum voltage and current of 500 V and 30 A, respectively, providing a maximum power of 15 kW.</p><p>　　Ⅱ. DESCRIPTIOONF THEP ROPOSED SYSTEM</p><p

33、>　　The scheme of the proposed system is presented in Fig. 1. It consists mainly of the electronic converter, shown in the central picture, the microcontroller, shown on the left and the photovoltaic generators and inv

34、erters, shown on the right.</p><p>　　Fig. 1. Proposed emulation-measurement system</p><p>　　The 15 kW experimental electronic converter prototype is the heart of the system. Its current is contr

35、olled by means of an inner analogical control loop.Together with the converter, a measuring board with the voltage and current sensors is included. The converter includes several electronic protections against over-volta

36、ges and over-currents. </p><p>　　The electronic converter can operate in two different modes: measuring and emulating. Both operation modes are driven by means of the DSP microcontroller, which is integrated

37、 in a PC.</p><p>　　In the measuring operation mode, the equipment is connected to a maximum of 7 different photovoltaic generators. A digital voltage control loop is then programmed in the microcontroller to

38、 make the photovoltaic generators cover their complete I- V characteristic curves. The voltage control loop provides the reference for the inner current loop. The characteristic curves are then continuously measured thre

39、e times per second. The data obtained are stored in the PC so that they can be both analyzed</p><p>　　In the emulating operation mode, the inverter to be tested is connected to the converter and the microcon

40、troller generates the current reference from the desired current-voltage pattern, which was obtained by measuring the evolution of the I-V characteristic curve of a particular photovoltaic generator. In this way, the equ

41、ipment behaves as a real-time emulator of any electrical array behavior that has been either programmed directly in the microcontroller or obtained by previous measurements in</p><p>　　As it was pointed out

42、in the introduction, the equipment can emulate the behavior of photovoltaic generators up to 15 kW, with maximum short-circuit currents and open-circuit voltages of 30 A and 500 V, respectively.</p><p>　　Fig

43、. 2. Structure of the electronic converter</p><p>　　Fig. 2 shows the structure of the proposed converter. As it can be observed, it consists of a bi-directional DC/DC converter, a filtering stage and an ener

44、gy dissipation circuit.</p><p>　　The converter, which is made up of two IGBT, TI and T2, and two diodes, DI and D2, is supplied by means of a rectified AC three-phase voltage source. The output of the conver

45、ter consists mainly of the inductor L and the capacitors C1 and C2, which permit the short and open-circuit operation. The other elements of the filter are designed with the aim of attenuating switching harmonics, while

46、eliminating resonant modes and minimizing losses.</p><p>　　In the emulating operation mode, the converter works as a Buck supplied by the rectified AC voltage. In this situation, the energy flows from the AC

47、 source to the photovoltaic inverter that is connected to the output of the proposed converter. In order to make the converter emulate the behavior of a photovoltaic generator, the measurement of the output voltage is se

48、nt to the external microcontroller (DSP), which calculates the current to be generated by the converter from the programmed I-V char</p><p>　　The current IL through the inductor L is controlled by means of t

49、he variable-hysteresis control loop shown in Fig. 3. This control loop permits the short-circuit operation that is required both to measure and to emulate the photovoltaic arrays. The filter at the output of the converte

50、r hardly affects the dynamics of the current control loop because it is designed to filter switching harmonics whose frequencies are higher than that expected for the current loop. In short, except for quick output </

51、p><p>　　The variable-hysteresis current control loop presented in Fig. 3 achieves constant frequency operation by means of tuning the hysteresis width AI as a unction of the duty cycle D. The hysteresis width i

52、s in fact the current ripple. The necessary limitation of this ripple will produce variable frequency behavior at low and high duty cycles. </p><p>　　In the measuring operation mode, the converter works as a

53、 Boost supplied by the photovoltaic generators. The energy coming from the photovoltaic generators is dissipated in the dissipation circuit, which consists of an IGBT, T3, a diode, D3, and a dissipation resistor, R. In t

54、his operation mode, the converter has to make the photovoltaic generators cover their complete I- V characteristic curves. </p><p>　　In principle, there are two options to cover the characteristic curve of a

55、 photovoltaic generator. It can be covered along either the current axis or the voltage axis. However, from the shape of the I-V characteristic curves, it is clear that better results will be obtained if the second optio