電氣外文翻譯--改進(jìn)的單周控制應(yīng)用于statcom

1、<p><b>　　英文原文</b></p><p>　　Application of Advanced One-cycle Control in STATCOM</p><p>　　0 Introductions</p><p>　　Static Synchronous Compensator (STATCOM) is a flex

2、ible AC transmission system, one of the core device, which through the power grid into or from the grid to absorb some of the reactive power, can stabilize the voltage, flicker suppression, power factor, etc. to improve.

3、 In order to ensure stable and reliable work of STATCOM, the control method of choice is very important. STATCOM current control methods used in the main have a direct current control and indirect current control, but mo

4、st of thes</p><p>　　Embarks from the instantaneous power principle of detailed balance, infers the inverter output current to the output voltage transformation relationship, thus has omitted the electric cur

5、rent PI regulator, reduced the controlled variable adjustment order of complexity, but this method needs the known STATCOM installment the equivalent resistance and the equivalent inductance value, but these two paramete

6、r generally with difficulty precision measuring. Embarks from the STATCOM structure, establis</p><p>　　Is insensitive based on single week control's static synchronous compensator (OCC-STATCOM) to system

7、's frequency departure, installment Lu good is very high, simultaneously only need carries on the examination to the input current and the STATCOM concurrent side voltage then, the control structure is simple, receiv

8、es the attention more and more. But as a result of the OCC-STATCOM main circuit power component existence inherent dead time, this will have the negative effect to its output's idle cu</p><p>　　1 One-cyc

9、le Control static synchronous compensator's principle </p><p>　　See Figure based on the single week control's single-phase STATCOM installment structure drawing 1, (sometimes installs is composed of

10、the voltage inverter and the connection reactor connects reactor also to use to connect transformer to replace). Sometimes, in connects between the reactor and the inverter also installs outputs the filter to filter the

11、high frequency burr signal which the inverter outputs. Its principle of work is, examines the STATCOM junction point electric current as well as </p><p>　　When STATCOM effective work, the power source side i

12、dle work output is 0, is equal after undergoing the compensation, the three-phase load for the pure resistance load, the net side current waveform completely tracks the voltage waveform. Considers the single-phase circui

13、t, may obtain the ideal control goal expression</p><p>　　In the formula, is the installment junction point voltage; is the net side electric current; R expresses after the control equivalent resistive load

14、. Supposes single week control the switching period is T, the duty factor is D. When , on the invertors the bridge arm break over, gets down the bridge arm to shut off; When, gets down the bridge arm break over, on the b

15、ridge arm shuts off. The theoretical analysis may know, when STATCOM effective work, and the D relations are</p><p><b>　　(1)</b></p><p>　　In the formula, , is the electric current

16、sampling resistance value; is the invertors concurrent side voltage. Considered the turn-on frequency is bigger than the network voltage frequency far, in a switching period basic invariable, type (1) may realize thro

17、ugh the single week control way. Takes single week constant of integration, may promote the single week governing equation is</p><p><b>　　(2)</b></p><p>　　May result in OOC-STATCOM

18、 according to type (2) the control scheme to see Figure 2. In chart,, for direct-current side electric capacity voltage datum value; obtains by () after the PI adjustment. The control circuit carries on the integral in

19、 each switching period to , when the integral valve conforms to type (2), the switching signal turn over, the integrated circuit repositions, waiting next cycle again integral, thus obtains satisfies-like (2) D.</p>

20、;<p>　　Fig. 1 Configuration of STATCOM based on one-cycle control</p><p>　　Fig. 2 Principle scheme of one-cycle control</p><p>　　Fig. 3 Schematic of Inverter Bridge</p><p>

21、;　　2 dead area effects compensate </p><p>　　Because in the invertors main circuit's power on-off element is not the perfect switch, to prevent the invertors high and low bridge arm to occur goes nonstop

22、to the short trouble, must establish a section of dead time in its driving signal, guaranteed after the identical bridge arm high and low two power tubes can shut off first, clears. Considers the single-phase circuit, su

23、pposes the control signal the dead time is , the invertors output inductance electric current inflow invertors direction </p><p>　?。╝）On L actual voltage waveform</p><p>　?。╞）On L ideal voltage

24、waveform</p><p>　?。╟）Actual and difference of the ideal voltage waveform</p><p>　　Fig. 4 Schematic of dead-time effect</p><p>　　When single week control effective work, has the fo

25、llowing relations</p><p><b>　　(3)</b></p><p>　　Considered that the dead area effect the influence, carries on the compensation to it. When is positive, switching period's duty

26、factor increases k, may obtain under the single week control requirement</p><p>　　The above equation simplifies may result in</p><p>　　Unites vertical (2) may result in this time's Shan Zhou

27、 the governing equation is</p><p><b>　　(4)</b></p><p>　　Likewise may promote, when for negative, reduces k switching period's duty factor, the single week governing equation is&

28、lt;/p><p><b>　　(5)</b></p><p>　　Contrast type (3) ~ (5) may know, only need increase an gain in the original control circuit's foundation is the 2k proportional component and a meas

29、uring current polar mark examination module then serves the control purpose. Improvement Shan Zhou the control scheme see Figure 5. In the chart, Sign indicates conforms to the function, when inputs >0, outputs 1, ot

30、herwise outputs - 1.</p><p>　　Fig. 5 Principle scheme of advanced one-cycle control</p><p>　　3 simulation result </p><p>　　To confirm proposed that control method's validity, th

31、is article uses Matlab to carry on the simulation analysis and with Shan who has not carried on the dead area compensation Zhou the control method compares. Artificial circuit's coil in voltage is 220 V, the frequenc

32、y is 50 Hz; The invertors concurrent side electric capacity is 2000 F, the voltage control in 500 V; Connects reactor 0.2 mH; Indirect of LC output filter invertors and connection reactors, inductance 1. 6 mH, electric c

33、apacity 31</p><p>　?。╝）has not put into when the STATCOM installment simulation oscillogram</p><p>　?。╞）has not considered when the dead area effect compensates the oscillogram</p><p&

34、gt;　　（c）after uses this article to propose the method compensation oscillogram</p><p>　　Fig. 6 Results of simulation</p><p>　　,, the simulation result see Figure 6. Its Chinese Library 6(a) for

35、has not put into when the STATCOM installment the simulation oscillogram; Figure 6(b) has not considered when the dead area compensation the oscillogram; Figure 6(c) is uses this article to propose time the control metho

36、d profile. The figure shows, installs when does not carry on the dead area compensation, after the compensation net side electric current voltage waveform has the big harmonic content. When uses this article prop</p&g

37、t;<p>　　In order to see the dead area to the pulse-duration modulation (PWM) voltage influence, the PWM oscillograms see Figure 7. And, the inventor output voltage is , the dead time hypothesis is 10, before Figur

38、e 7 (a) is inserts the person dead area the PWM profile, after Figure 7(b) is inserts the person dead area the PWM profile. As seen in Figure 7, inserts the person dead area before and after PWM pulse width obvious diffe

39、rent, after passing through an inertial element obviously, after inserting </p><p>　　Before (a) insertion dead area, inverter output voltage</p><p>　　After (b) insertion dead area, inverter outp

40、ut voltage</p><p>　　Fig.7 PWM waveform</p><p>　　4 conclusions </p><p>　　Is insensitive based on the single week control's static synchronous compensator to system's freque

41、ncy departure, installment robustness is high. But the static synchronous compensator's main circuit power component existence inherent dead time, causes the inverter output wave shape to contain the massive overtone

42、s, serious influence STATCOM work effect. This article has analyzed the single week control principle and inverter’s dead area effect. The dead area existence was equal in changing the </p><p><b>　　中文譯

43、文</b></p><p>　　改進(jìn)的單周控制應(yīng)用于STATCOM</p><p><b>　　0引言</b></p><p>　　靜止同步補(bǔ)償器(STATCOM)是柔性交流輸電系統(tǒng)的核心裝置之一，它通過(guò)向電網(wǎng)注入或從電網(wǎng)吸收一定的無(wú)功功率，可以穩(wěn)定電壓、抑制閃變、提高功率因數(shù)等。為保證STATCOM穩(wěn)定可靠工作，選擇合適的控制方法

44、很重要。目前應(yīng)用于STATCOM的控制方法主要有直接電流控制和間接電流控制，但這些控制方法大多涉及多個(gè)控制參數(shù)的協(xié)同調(diào)整，實(shí)現(xiàn)較為困難。</p><p>　　從瞬時(shí)功率平衡原理出發(fā)，推導(dǎo)出逆變器輸出電流到輸出電壓的變換關(guān)系式，從而省去了電流PI調(diào)節(jié)器，降低了控制參數(shù)調(diào)整的復(fù)雜度，但該方法需已知STATCOM裝置的等效電阻和等效電感值，而這兩個(gè)參數(shù)一般難以精確測(cè)量。從STATCOM的結(jié)構(gòu)出發(fā)，建立其在dq坐標(biāo)系下的

45、微分方程，通過(guò)求解微分方程，直接得到STATCOM的控制關(guān)系式。但這種控制方法需要對(duì)STATCOM進(jìn)行精確建模，很難達(dá)到。</p><p>　　基于單周控制的靜止同步補(bǔ)償器(OCC-STATCOM)對(duì)系統(tǒng)的頻率偏差不敏感，裝置的魯棒性很高，同時(shí)只需對(duì)輸入電流和STATCOM直流側(cè)電壓進(jìn)行檢測(cè)即可，控制結(jié)構(gòu)簡(jiǎn)單，越來(lái)越受到關(guān)注。但由于OCC-STATCOM主電路功率器件存在固有的死區(qū)時(shí)間，這將對(duì)其輸出的無(wú)功電流幅值

46、和相位產(chǎn)生消極影響，從而降低裝置的無(wú)功補(bǔ)償效果。本文針對(duì)OCC-STATCOM的工作原理及其存在的問(wèn)題進(jìn)行分析，通過(guò)改變單周控制方程中的占空比實(shí)現(xiàn)對(duì)逆變器功率器件死區(qū)的補(bǔ)償，以提高STATCOM控制器的精度。</p><p>　　1單周控制靜止同步補(bǔ)償器的原理</p><p>　　基于單周控制的單相STATCOM裝置結(jié)構(gòu)圖見(jiàn)圖1，裝置由電壓型逆變器和連接電抗器組成(連接電抗器有時(shí)也用連接變

47、壓器代替)。有時(shí)，在連接電抗器和逆變器之間還裝設(shè)輸出濾波器以濾除逆變器輸出的高頻毛刺信號(hào)。其工作原理是，檢測(cè)STATCOM接入點(diǎn)電流以及逆變器直流側(cè)電容電壓，通過(guò)單周算法控制逆變器的電壓輸出，實(shí)現(xiàn)STATCOM向電網(wǎng)注入適當(dāng)?shù)某盎蛘邷蟮臒o(wú)功電流，達(dá)到調(diào)節(jié)功率因數(shù)的目的。</p><p>　　當(dāng)STATCOM有效工作時(shí)，電源側(cè)無(wú)功輸出為0，相當(dāng)于經(jīng)過(guò)補(bǔ)償后，三相負(fù)載為純電阻性負(fù)載，網(wǎng)側(cè)電流波形完全跟蹤電壓波形。

48、考慮單相電路，可以得出理想的控制目的表達(dá)式</p><p>　　式中，為裝置接入點(diǎn)電壓; 為網(wǎng)側(cè)電流;R表示經(jīng)控制后等效電阻負(fù)載。設(shè)單周控制的開(kāi)關(guān)周期為T(mén)，占空比為D。當(dāng)時(shí)，逆變器上橋臂導(dǎo)通，下橋臂關(guān)斷;當(dāng)時(shí)，下橋臂導(dǎo)通，上橋臂關(guān)斷。理論分析可知，當(dāng)STATCOM有效工作時(shí)，與D間的關(guān)系為</p><p><b>　　(1)</b></p><p&

49、gt;　　式中，，為電流采樣電阻值; 為逆變器直流側(cè)電壓?？紤]到開(kāi)關(guān)頻率遠(yuǎn)大于電網(wǎng)電壓頻率，在一個(gè)開(kāi)關(guān)周期內(nèi)基本不變，式(1)可通過(guò)單周控制的方式實(shí)現(xiàn)。取單周積分常數(shù)，可推出單周控制方程為</p><p><b>　　(2)</b></p><p>　　根據(jù)式(2)可得OOC-STATCOM的控制原理圖見(jiàn)圖2。圖中，，為直流側(cè)電容電壓基準(zhǔn)值; 由()經(jīng)PI調(diào)節(jié)得到。控

50、制電路在每個(gè)開(kāi)關(guān)周期均對(duì)進(jìn)行積分，當(dāng)積分值符合式(2)時(shí)，開(kāi)關(guān)信號(hào)翻轉(zhuǎn)，積分電路復(fù)位，等待下一周期重新積分，從而得到滿足式(2)的D。</p><p>　　圖1基于單周控制的STATCOM裝置結(jié)構(gòu)圖</p><p><b>　　圖2單周控制原理圖</b></p><p><b>　　圖3逆變橋示意圖</b></p&g

51、t;<p><b>　　2死區(qū)效應(yīng)補(bǔ)償</b></p><p>　　由于逆變器主電路中的功率開(kāi)關(guān)元件不是理想開(kāi)關(guān)，為防止逆變器上下橋臂發(fā)生直通短路故障，必須在其驅(qū)動(dòng)信號(hào)中設(shè)置一段死區(qū)時(shí)間，以保證同一橋臂上下兩功率管能先關(guān)斷后開(kāi)通?？紤]單相電路，設(shè)控制信號(hào)的死區(qū)時(shí)間為，逆變器輸出電感電流流入逆變器方向?yàn)檎孀儤蚴疽鈭D見(jiàn)圖3。圖中，為IGBT; 為快速恢復(fù)續(xù)流二級(jí)管。在中，逆變器

52、輸出電壓大小和的方向有關(guān)。當(dāng)為正時(shí)，通過(guò)和續(xù)流，逆變器輸出電壓為;當(dāng)為負(fù)時(shí)，通過(guò)和續(xù)流，逆變器輸出電壓為。死區(qū)效應(yīng)波形示意圖見(jiàn)圖4，輸出電感L上的實(shí)際電壓波形、理想電壓波形以及兩者之差，如圖4中(a),(b), (c)所示。設(shè)，則為正時(shí)， , 的延時(shí)導(dǎo)通對(duì)電路不產(chǎn)生影響，而 , 的延時(shí)導(dǎo)通，此時(shí)占空比變?yōu)?)?？紤]式(2)可知，占空比的改變，將會(huì)嚴(yán)重影響單周控制的控制精度，即因死區(qū)的存在，使得逆變器輸出的無(wú)功電流包含大量的諧波，從而影響

53、了STATCOM的工作效果，為此，本文提出了一種改進(jìn)單周控制策略。</p><p>　　(a)L上的實(shí)際電壓波形</p><p>　　(b) L上的理想電壓波形</p><p>　　(c)實(shí)際與理想電壓波形之差</p><p>　　圖4死區(qū)效應(yīng)波形示意圖</p><p>　　在單周控制有效工作時(shí)，有如下關(guān)系</p

54、><p><b>　　(3)</b></p><p>　　考慮死區(qū)效應(yīng)的影響，對(duì)其進(jìn)行補(bǔ)償。當(dāng)為正時(shí)，將開(kāi)關(guān)周期的占空比增大k，則在單周控制條件下可得出</p><p><b>　　上式化簡(jiǎn)可得</b></p><p>　　聯(lián)立式(2)可得此時(shí)的單周控制方程為</p><p>&

55、lt;b>　　(4)</b></p><p>　　同理可推出，當(dāng)為負(fù)時(shí)，將開(kāi)關(guān)周期的占空比減小k，單周控制方程為</p><p><b>　　(5)</b></p><p>　　對(duì)比式(3)~(5)可知，只需在原控制電路的基礎(chǔ)上增加一個(gè)增益為2k的比例環(huán)節(jié)和一個(gè)測(cè)量電流極性的符號(hào)檢測(cè)模塊即可達(dá)到控制目的。改進(jìn)的單周控制原理圖見(jiàn)

56、圖5。圖中，Sign表示符合函數(shù)，當(dāng)輸入>0時(shí)，輸出1，否則輸出1。</p><p>　　圖5改進(jìn)單周控制原理圖</p><p><b>　　3仿真結(jié)果</b></p><p>　　為了驗(yàn)證提出控制方法的有效性，本文利用Matlab進(jìn)行仿真分析，并與未進(jìn)行死區(qū)補(bǔ)償?shù)膯沃芸刂品椒ū容^。仿真電路的進(jìn)線電壓為220 V，頻率為50 Hz;逆變器

57、直流側(cè)電容為2000 F，電壓控制在500 V;連接電抗器0.2 mH;逆變器和連接電抗器之間接一LC輸出濾波器，電感1. 6 mH，電容31F;全橋逆變部分開(kāi)關(guān)頻率為5 kHz;直流電壓環(huán)的積分時(shí)間常數(shù)為0. 1ms。</p><p>　　(a)未投入STATCOM裝置時(shí)的仿真波形圖</p><p>　　(b)未考慮死區(qū)效應(yīng)時(shí)補(bǔ)償波形圖</p><p>　　(c)

58、采用本文提出方法補(bǔ)償后的波形圖</p><p><b>　　圖6仿真結(jié)果圖</b></p><p>　　,，仿真結(jié)果見(jiàn)圖6。其中圖6(a)為未投入STATCOM裝置時(shí)的仿真波形圖;圖6(b)為未考慮死區(qū)補(bǔ)償時(shí)的波形圖;圖6(c)為采用本文所提出控制方法時(shí)的波形。由圖可見(jiàn)，裝置不進(jìn)行死區(qū)補(bǔ)償時(shí)，經(jīng)補(bǔ)償后的網(wǎng)側(cè)電流電壓波形都有較大的諧波含量。而采用本文所提出控制方法時(shí)，網(wǎng)

59、側(cè)波形較理想，表明能夠有效消除死區(qū)效應(yīng)的消極影響，提高裝置的控制精度。</p><p>　　為了看出死區(qū)對(duì)脈寬調(diào)制(PWM)電壓的影響，PWM波形圖見(jiàn)圖7。其中，逆變器輸出電壓為,死區(qū)時(shí)間設(shè)定為10，圖7 (a)為插人死區(qū)前的PWM波形，圖7(b)為插人死區(qū)后的PWM波形。由圖7可見(jiàn)，插人死區(qū)前、后的PWM脈寬明顯不同，經(jīng)過(guò)一個(gè)慣性環(huán)節(jié)后可見(jiàn)，插人死區(qū)后的PWM波形不再是光滑的正弦波，而是包含有大量的高次諧波，這

60、即為圖6(b)產(chǎn)生諧波的原因。另外可見(jiàn)，PWM波的幅值穩(wěn)定在500 V，即直流側(cè)電壓能穩(wěn)定在500 V 。</p><p>　　插入死區(qū)前逆變器輸出電壓</p><p>　　插入死區(qū)后逆變器輸出電壓</p><p>　　圖7 PWM波形圖</p><p><b>　　4結(jié)語(yǔ)</b></p><p&g

61、t;　　基于單周控制的靜止同步補(bǔ)償器對(duì)系統(tǒng)的頻率偏差不敏感，裝置的魯棒性高。但靜止同步補(bǔ)償器的主電路功率器件存在固有死區(qū)時(shí)間，使得逆變器輸出波形包含大量的諧波，嚴(yán)重影響了STATCOM的工作效果。本文分析了單周控制的原理和逆變器的死區(qū)效應(yīng)。死區(qū)的存在相當(dāng)于改變了單周控制的占空比:當(dāng)逆變器輸出電流為正時(shí)，減小了占空比;當(dāng)逆變器輸出電流為負(fù)時(shí)，增大了占空比。本文提出了一種改進(jìn)單周控制策略，根據(jù)逆變器輸出電流的方向，對(duì)占空比進(jìn)行預(yù)補(bǔ)償，并推導(dǎo)