【摘要】：風(fēng)能是太陽能的另一種存在方式,具有取之不盡、用之不竭、無污染、廉價等優(yōu)點。風(fēng)力發(fā)電相比于太陽能、核能等新能源具有最優(yōu)的成本效益,因此世界各國都在積極發(fā)展風(fēng)力發(fā)電。為了規(guī)范新能源并網(wǎng),各國針對新能源并網(wǎng)推出了各自的并網(wǎng)導(dǎo)則,其中對低電壓穿越能力(Low Voltage Ride Through,LVRT)有明確的嚴(yán)格要求。雙饋感應(yīng)風(fēng)力發(fā)電機(Double-Fed Induction Generator,DFIG)因其具有變換器容量小、重量輕、損耗低、可變速恒頻運行等優(yōu)點,占據(jù)風(fēng)電市場主要份額。因此研究DFIG的低電壓穿越具有代表性意義。首先,本文基于三相靜止ABC坐標(biāo)系和兩相旋轉(zhuǎn)dq坐標(biāo)系建立了 DFIG的數(shù)學(xué)模型,分析DFIG的工作原理,之后基于功率解耦的數(shù)學(xué)模型以及同步旋轉(zhuǎn)dq坐標(biāo)系的數(shù)學(xué)模型介紹了矢量控制策略。其次,針對傳統(tǒng)矢量控制策略下DFIG系統(tǒng)低電壓穿越能力弱,需改進控制算法的問題,介紹狀態(tài)反饋精確線性化與變結(jié)構(gòu)控制理論,通過狀態(tài)反饋精確線性化理論將DFIG非線性、強耦合的數(shù)學(xué)模型線性化,并利用動態(tài)響應(yīng)速度快的變結(jié)構(gòu)控制理論設(shè)計系統(tǒng)低電壓穿越控制器。在MATLAB中,搭建6× 1.5MW系統(tǒng)。通過仿真驗證,狀態(tài)反饋精確線性化變結(jié)構(gòu)控制較傳統(tǒng)矢量控制能有效提高雙饋風(fēng)力發(fā)電系統(tǒng)低電壓穿越能力。最后,針對電網(wǎng)電壓大幅跌落,添加轉(zhuǎn)子側(cè)Crowbar電路和直流側(cè)卸荷電路,分析了 Crowbar電路阻值的選取和投切時間對低電壓穿越效果的影響。針對Crowbar電路接入后,雙饋發(fā)電機以異步電機運行從電網(wǎng)吸收無功功率,不利于電網(wǎng)電壓恢復(fù)的問題,通過將定子電壓參考值與定子端電壓相減,經(jīng)PI調(diào)節(jié)后再與系統(tǒng)的實時無功功率相減,再經(jīng)PI調(diào)節(jié)后得到無功電流的給定值,優(yōu)化電網(wǎng)側(cè)變換器無功功率控制策略。在Crowbar電路投入運行后,控制網(wǎng)側(cè)變換器向電網(wǎng)輸出無功以支撐電網(wǎng)電壓恢復(fù)。
[Abstract]:Wind energy is another way of solar energy, which has the advantages of inexhaustible, pollution-free, cheap and so on. Compared with solar energy, nuclear energy and other new energy, wind power generation has the best cost-effectiveness, so all countries in the world are actively developing wind power generation. In order to standardize the grid connection of new energy, various countries have put forward their own grid connection guidelines for new energy, which has strict requirements for low voltage traversing capability (Low Voltage Ride Through,LVRT). Doubly-fed induction wind turbine (Double-Fed Induction Generator,DFIG) has the advantages of small capacity, light weight, low loss, variable speed and constant frequency operation, so it occupies the main share of wind power market. So it is significant to study the low voltage traversal of DFIG. Firstly, based on three-phase static ABC coordinate system and two-phase rotating dq coordinate system, the mathematical model of DFIG is established, and the working principle of DFIG is analyzed. Then the vector control strategy is introduced based on the power decoupling mathematical model and the synchronous rotating dq coordinate system. Secondly, aiming at the low voltage traversing ability of DFIG system under traditional vector control strategy and the need to improve the control algorithm, the state feedback exact linearization and variable structure control theory are introduced. The DFIG is nonlinear by the state feedback exact linearization theory. The strong coupling mathematical model is linearized and the low voltage traversing controller is designed by using the variable structure control theory with fast dynamic response. In MATLAB, a 6 脳 1.5MW system is built. The simulation results show that the state feedback accurate linearization variable structure control can effectively improve the low voltage traversing ability of the doubly-fed wind power generation system compared with the traditional vector control. Finally, the influence of the selection of Crowbar circuit resistance and switching time on the low voltage traversing effect is analyzed by adding rotor side Crowbar circuit and DC side unloading circuit to the large drop of power grid voltage. In view of the problem that the doubly-fed generator absorbs reactive power from the power network by asynchronous motor after the Crowbar circuit is connected, which is not conducive to the voltage recovery of the power grid, the reference value of the stator voltage and the stator terminal voltage are subtracted by subtracting the stator voltage reference value from the stator terminal voltage. After being adjusted by PI and subtracted from the real-time reactive power of the system, the given value of reactive power current is obtained by PI regulation, and the reactive power control strategy of power side converter is optimized. After the Crowbar circuit is put into operation, the grid side converter is controlled to output reactive power to the power grid to support the grid voltage recovery.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TM614

【參考文獻】

相關(guān)期刊論文 前10條

1 ;2016年中國風(fēng)電裝機容量統(tǒng)計[J];風(fēng)能;2017年02期

2 王慶龍;譚敏;李國麗;楊淑英;謝震;;雙饋風(fēng)力發(fā)電機電網(wǎng)磁鏈定向矢量控制實驗[J];合肥學(xué)院學(xué)報(自然科學(xué)版);2015年04期

3 羅名煜;陸暢;沈攀;李紅;韓楊;;大規(guī)模DFIG風(fēng)電場接入對電網(wǎng)的影響及其對策研究[J];電源學(xué)報;2015年05期

4 王振樹;劉巖;雷鳴;卞紹潤;石云鵬;;基于Crowbar的雙饋機組風(fēng)電場等值模型與并網(wǎng)仿真分析[J];電工技術(shù)學(xué)報;2015年04期

5 栗然;王倩;盧云;劉會蘭;祝晉堯;;Crowbar阻值對雙饋感應(yīng)發(fā)電機低電壓穿越特性的影響[J];電力自動化設(shè)備;2014年04期

6 凌禹;蔡旭;汪寧渤;;定子撬棒和直流側(cè)卸荷電路協(xié)調(diào)的故障穿越技術(shù)[J];中國電力;2013年12期

7 徐海亮;章瑋;賀益康;陳建生;;雙饋型風(fēng)電機組低電壓穿越技術(shù)要點及展望[J];電力系統(tǒng)自動化;2013年20期

8 楊偉;易成星;曲藝;;風(fēng)電大規(guī)模并網(wǎng)對系統(tǒng)暫態(tài)穩(wěn)定性的影響[J];電力學(xué)報;2013年04期

9 田云飛;張立濤;徐昊亮;;大規(guī)模風(fēng)電并網(wǎng)對電力系統(tǒng)的影響及應(yīng)對措施[J];電氣自動化;2013年03期

10 賈書杰;徐建源;朱鈺;王剛;程緒可;;風(fēng)電場的功率波動對電網(wǎng)電壓穩(wěn)定性影響研究[J];東北電力技術(shù);2013年02期

，

本文編號：2351052