風力發(fā)電機外文翻譯

1、<p>　　畢業(yè)設計（外文翻譯）</p><p>　　題 目 在電網(wǎng)電壓不平衡條件下的動態(tài)建模和風力渦輪機的直接功率控制 </p><p>　　系 （院） 自動化系 </p><p>　　專 業(yè) 電氣工程與自動化 </p><p>　　學生姓名

2、 </p><p>　　學 號 2007090124 </p><p>　　指導教師 </p><p>　　職 稱 </p><p>　　2011年 3月 8日</p>&l

3、t;p>　　Dynamic modeling and direct power control of wind turbine driven DFIG under unbalanced network voltage condition</p><p>　　Abstract: This paper proposes an analysis and a direct power control (DPC) d

4、esign of a wind turbine driven doubly-fed induction generator(DFIG)under unbalanced network voltage conditions. A DFIG model described in the positive and negative synchronous reference frames is presented. Variations of

5、 the stator output active and reactive powers are fully deduced in the presence of negative sequence supply voltage and rotor flux. An enhanced DPC scheme is proposed to eliminate stator active power osci</p><

6、p>　　Key words: Doubly-fed induction generator (DFIG) Wind turbine, Direct power control (DPC), Stator voltage oriented (SVO), Unbalanced network</p><p>　　INTRODUCTION,Wind farms based on the doubly-fed in

7、duction generators (DFIG) with converters rated at 25%~30%of the generator rating for a given rotor speed variation range of±25%are becoming increasingly popular. Compared with the wind turbines using fixed speed in

8、duction generators or fully-fed synchronous generators with full-size converters the DFIG-based wind turbines offer not only the advantages of variable speed operation and four-quadrant active and reactive power capabili

9、ties, but also </p><p>　　Similar to direct torque control (DTC) of induction machines presented a few decades ago, which behaves as an alternative to vector control, direct power control (DPC)of DFIG-based w

10、ind turbine systems has been proposed recently(Gokhaleet al.,2002;Xu and Cartwright,2006;Zhi and Xu,2007). In (Gokh a le et al., 2002), the control scheme was based on the estimated rotor flux. Switching vectors were sel

11、ected from the optimal switching table using the estimated rotor flux position and the errors of r</p><p>　　This paper investigates an improved DPC scheme for a DFIG wind power generation system under unbala

12、nced network conditions. In the SVO dq reference frame, a mathematical DPC model of a DFIG system with balanced supply is presented, which is referred to as the conventional model in this paper. Then during network unbal

13、ance, a modified DFIG DPC model in the SVO positive dq and negative dq reference frames is developed .Based on the developed model, a system control strategy is proposed by eliminat</p><p>　　SIMULATION STUDI

14、ES,Simulations of the proposed DPC strategy for a DFIG-based wind power generation system were conducted using PSCAD/EMTDC. </p><p>　　A single-phase load at the primary side of the coupling transformer was u

15、sed to generate the voltage unbalance. The nominal DC link voltage was set at 1 200 V and the switching frequencies for both converters were 2 000 Hz. The main target of the grid side converter was assigned to control th

16、e DC link voltage with the similar method used in(Song and Nam,1999;Hu et al.,2007).As shown in Fig.7,a high frequency AC filter is shunt-connected to the stator side to absorb the switching harmonics genera</p>&

17、lt;p>　　converters. Initial studies with various active and reactive power steps were carried out to test the dynamic response using the conventional control scheme shown in Fig.4 in the conditions of balanced supply v

18、oltage. First, the DFIG was assumed to be in speed control, viz., the rotor speed was set externally, as the large inertia of the wind turbine resulting in a slow change of the rotor speed. The active and reactive powers

19、 were initially set at 0 MW and0.5 MV·A, respectively, where refers to</p><p>　　CONCLUSION，This paper has proposed an analysis and an improved DPC design for a DFIG-based wind power generation system du

20、ring network voltage unbalance. Simulation results were presented to demonstrate the feasibility of the proposed control scheme. Conclusions can be drawn as follows: (1)The conventional DPC scheme without net-work unbala

21、nce considered can provide pretty good dynamic system performance when the supply voltage is strictly balanced. However, once the net-work is slightly unbalan</p><p>　　動態(tài)建模與驅(qū)動的雙饋風力發(fā)電機直接供電網(wǎng)絡的電壓不平衡條件下的控制</p

22、><p>　　摘要：本文提出了一種分析和直接功率控制（DPC）的驅(qū)動的不平衡電網(wǎng)電壓條件下雙饋感應發(fā)電機（雙饋）風力發(fā)電機組的設計。一個雙饋模型中描述的正面和負面的同步提出了參考框架。變化的定子輸出有功，無功的權(quán)力是完全推導出的負序電壓和轉(zhuǎn)子磁鏈的存在。增強的DPC的計劃，提出在網(wǎng)絡，以消除不平衡定子有功功率振蕩。建議中的管制機制將消除轉(zhuǎn)子電流調(diào)節(jié)器和正，負序轉(zhuǎn)子電流分解處理。仿真結(jié)果使用PSCAD / EMTDC的

23、提出在2兆瓦雙饋風力發(fā)電系統(tǒng)，以驗證網(wǎng)絡下的平衡和不平衡的狀況下，提出的控制方案的可行性。</p><p>　　關(guān)鍵詞：雙饋感應發(fā)電機（雙饋）風力發(fā)電機組，直接功率控制（DPC），定子電壓定向，非平衡網(wǎng)絡</p><p>　　風力發(fā)電場的雙饋感應發(fā)電機與轉(zhuǎn)換器在25％?30給定轉(zhuǎn)子速度變化范圍± 25％額定發(fā)電機（雙饋）的基礎正在變得越來越受歡迎。相對于采用固定速異步風力發(fā)電機或

24、完全夠了全尺寸的轉(zhuǎn)換器，同步發(fā)電機雙饋型風力渦輪機不僅提供了變速操作和四象限有功，無功功率能力渦輪機的優(yōu)點，同時也降低轉(zhuǎn)換器成本和功率損耗。然而，無論輸配電網(wǎng)絡通?？梢杂行〉姆€(wěn)態(tài)和瞬態(tài)電壓不平衡大。如果電壓不平衡不是由雙饋電機控制系統(tǒng)的考慮，定子電流極不平衡，甚至可能成為一個小定子電壓不平衡。創(chuàng)建不平等的不平衡電流加熱定子繞組，在電磁轉(zhuǎn)矩和定子輸出有功，無功權(quán)力?？刂婆c雙饋風力發(fā)電機組的條件下不平衡網(wǎng)絡系統(tǒng)的運行是基于傳統(tǒng)或定子磁場定向

25、或定子電壓導向矢量控制采用雙皮（在正面和負面的同步旋轉(zhuǎn)坐標系實施比例積分）電流調(diào)節(jié)器，分別具有測量轉(zhuǎn)子分解為正，負序分量電流來控制它們。這種方法的一個主要缺點是，分解的時間序列的轉(zhuǎn)子組件介紹當前的延誤可能會影響整個系統(tǒng)的穩(wěn)定性和動態(tài)響應。因此，一個電流控制計劃按比例諧振（PR）在定子靜止坐標系的基礎上，提出監(jiān)管機構(gòu)在它可以直接控制的順序分解而不需要轉(zhuǎn)子電流。鑒于，對矢量控制方案的性能，高度依賴于如定子</p><p&

26、gt;　　類似的直接轉(zhuǎn)矩控制的感應電機器（DTC）提出了幾十年前，它作為一個矢量控制的替代行為，直接功率控制（DPC）的的雙饋型風力發(fā)電機組已經(jīng)提出了近期該控制方案是基于轉(zhuǎn)子磁通估計。交換載體選自最優(yōu)開關(guān)使用轉(zhuǎn)子磁通估計位置和轉(zhuǎn)子磁通與有功功率表的錯誤。轉(zhuǎn)子磁通參考乃采用無功功率的參考。由于轉(zhuǎn)子供電頻率，相當于雙饋電機轉(zhuǎn)差頻率，可能非常低，轉(zhuǎn)子磁通估計可能有重大影響的機床參數(shù)的變化。對估計的定子磁鏈為基礎，提出了DPC的戰(zhàn)略。由于定子電

27、壓相對諧波和無頻率固定，雙饋電機定子磁鏈估計精度可以得到保證。交換載體選自最優(yōu)開關(guān)利用估計定子磁鏈的位置和有功，無功權(quán)力的錯誤表。因此，控制系統(tǒng)簡單，機器的參數(shù)對系統(tǒng)性能的影響被認為是不可靠的。然而，像傳統(tǒng)的存款，縮節(jié)胺具有開關(guān)頻率不固定的問題，由于對有功和無功功率的變化，發(fā)電機的轉(zhuǎn)速和功率控制器的磁滯帶寬顯著影響。最近，修改后的DPC的戰(zhàn)略已經(jīng)提出根據(jù)證券及期貨條例的雙饋型風力發(fā)電具有恒定的開關(guān)頻率同步發(fā)電系統(tǒng)矢量控制的參照系。該控制

28、方法直接計算出每個開關(guān)周期內(nèi)所需的旋翼控制電壓的基礎上，估計定子磁鏈，主動和被動的權(quán)力和他們的錯誤。該控制策略提供了改善，與定子（</p><p>　　本文研究了雙饋風力發(fā)電的網(wǎng)絡條件下的不平衡產(chǎn)生的DPC系統(tǒng)的改進方案。在主導方向的作用下，一個數(shù)學的DPC與供求平衡的雙饋系統(tǒng)模型提出了一種被稱為本文中的傳統(tǒng)模式。然后在網(wǎng)絡失衡，修改后的雙饋縮節(jié)胺在高級獸醫(yī)師正面和負面的電話號碼查詢電話號碼查詢參考框架模型。模型

29、的基礎上開發(fā)的，系統(tǒng)的控制策略，提出了消除了定子輸出網(wǎng)絡條件下的不平衡有功功率振蕩。最后，在一個2兆瓦雙饋風力發(fā)電系統(tǒng)的仿真結(jié)果的正確性，并證明該控制策略的可行性。</p><p>　　擬議的DPC的雙饋型風力發(fā)電系統(tǒng)的策略進行了模擬使用PSCAD / EMTDC的。在一個耦合變壓器一次側(cè)單相負載是用來產(chǎn)生的電壓不平衡。標稱直流母線電壓設定在1 200 V和兩個轉(zhuǎn)換器的開關(guān)頻率為2 000赫茲。該電網(wǎng)側(cè)變換器的主

30、要目標是控制與分配使用的類似方法的直流母線電壓。各種有功、無功功率的步驟進行了初步研究，以測試使用的動態(tài)響應常規(guī)的控制計劃，圖4所示的均衡供應電壓的條件。首先，雙饋被認為是速度控制，即，轉(zhuǎn)子轉(zhuǎn)速為外部設定為風在轉(zhuǎn)子的速度緩慢變化引起的汽輪機大慣性。各種電源應用步驟，即，有功、無功引用從0變化到2的即時的1.3兆瓦。</p><p>　　結(jié)論:本文提出了一種分析和改進的DPC的雙饋型風力發(fā)電在電網(wǎng)電壓不平衡的系統(tǒng)設

31、計。仿真結(jié)果提交證明該控制方案的可行性。可以得出結(jié)論如下：（1）傳統(tǒng)的DPC沒有網(wǎng)絡工作考慮不平衡方案能提供不錯的動力系統(tǒng)性能時，電源電壓為嚴格平衡。但是，一旦網(wǎng)絡工作稍有不平衡，性能惡化，高定子/轉(zhuǎn)子電流不平衡，在定子有功/無功功率和電磁轉(zhuǎn)矩顯著振蕩。 （2）擬議DPC的計劃，這是高級獸醫(yī)師積極的電話號碼查詢+和消極電話號碼查詢參照系實施，取得了積極和負序矢量控制方案的轉(zhuǎn)子電流分解過程中擺脫使用雙皮轉(zhuǎn)子加強了消除定子輸出有功功率振蕩和