雙饋風力發(fā)電系統(tǒng)串電阻低電壓穿越控制研究
發(fā)布時間：2019-03-01 14:33
【摘要】：能源危機和環(huán)境污染，，加大了人類對可再生能源的需求，近年來風力發(fā)電技術作為主流新能源之一獲得了突飛猛進的發(fā)展。隨著風電機組容量的日益增大以及風電滲透率的不斷提高，風電與電網(wǎng)之間的相互影響引起了廣泛的重視。DFIG作為當前兩大主流機型之一，因其結構原因在電網(wǎng)電壓出現(xiàn)跌落故障時，會出現(xiàn)轉子過電流和過電壓、直流母線電壓波動等問題，嚴重時風機的解列還可能造成電網(wǎng)的大面積癱瘓。因此，電網(wǎng)故障條件下保證雙饋風電機組的不脫網(wǎng)運行成為新的研究熱點。本文以電網(wǎng)電壓跌落條件下的雙饋風電系統(tǒng)為研究對象，設計了外接保護裝置和優(yōu)化DFIG勵磁策略的低電壓穿越方案，并通過仿真和實驗對方案的可行性進行了驗證。 首先，基于PSCAD/EMTDC軟件搭建了雙饋風力發(fā)電系統(tǒng)的數(shù)學模型，并在此基礎上分析了雙饋感應發(fā)電機的工作原理及其矢量控制策略。之后，對電網(wǎng)電壓嚴重跌落情況下雙饋感應電機的電磁暫態(tài)特性進行了理論的分析和仿真驗證。 其次，提出了一種適用寬功率因數(shù)范圍的串接連續(xù)可調電阻的硬件保護方案。設計的保護裝置采用三單相結構，串接在風機升壓變壓器高壓側和匯流母線之間，每相裝置均由功率二極管構成的不控整流電路及并聯(lián)IGBT的電阻共同組成�？紤]電網(wǎng)故障初始時引起的暫態(tài)現(xiàn)象最為嚴重，采用全幅值補償策略計算等效電阻初值，保證了電網(wǎng)電壓跌落時刻機端電壓的穩(wěn)定。同時設計了低功率因數(shù)優(yōu)化控制策略，提升了保護裝置在低功率因數(shù)工作環(huán)境的穩(wěn)壓效果。 然后，提出了基于滑模定子磁鏈觀測器的滅磁控制策略。采用滑模磁鏈觀測器對DFIG定子磁鏈進行跟蹤，將觀測到的磁鏈與其經(jīng)50Hz帶通濾波器后得到的交流分量作差，獲取定子磁鏈的直流分量。之后，控制機側變流器勵磁電流，使之建立與磁鏈直流分量反向的漏磁場，加速了暫態(tài)直流分量的衰減。對滅磁控制策略的仿真結果驗證了該方案的有效性。 最后，搭建了包含小型風電系統(tǒng)網(wǎng)側變換器和電阻保護裝置的實驗平臺，進行了電網(wǎng)電壓跌落故障的低電壓穿越實驗研究。串接電阻的低電壓穿越保護裝置采用DSP2812作為主控芯片，調節(jié)PWM占空比，實現(xiàn)串接的等效電阻阻值調節(jié)。最后模擬了三相電壓對稱跌落跌落故障，串入電阻保護裝置后使得機端電壓維持在期望范圍，驗證了所設計的電阻保護裝置的有效性，同時再次驗證了理論研究的正確性。
[Abstract]:Energy crisis and environmental pollution have increased human demand for renewable energy. Wind power generation technology as one of the mainstream new energy has been developed by leaps and bounds in recent years. With the increasing capacity of wind turbine and the increasing permeability of wind power, the interaction between wind power and power grid has attracted extensive attention. DFIG, as one of the two mainstream models at present, has attracted more and more attention. Due to its structural reasons, the overcurrent and overvoltage of the rotor and the voltage fluctuation of the DC bus will occur when the voltage drop occurs in the power network. In serious cases, the unwinding of the fan may also cause the large area paralysis of the power network. Therefore, it is a new research hotspot to ensure the operation of doubly-fed wind turbine under the condition of power grid failure. Taking the doubly-fed wind power system under the condition of voltage sag as the research object, this paper designs an external protection device and a low voltage traversal scheme to optimize the excitation strategy of DFIG. The feasibility of the scheme is verified by simulation and experiment. Firstly, the mathematical model of doubly-fed wind power generation system is built based on PSCAD/EMTDC software, and the working principle and vector control strategy of doubly-fed induction generator are analyzed. Then, the electromagnetic transient characteristics of doubly-fed induction machine under the condition of serious voltage sags are analyzed theoretically and verified by simulation. Secondly, a hardware protection scheme, which is suitable for wide power factor range, is proposed. The designed protection device adopts a three-phase structure, connected in series between the high-voltage side of the fan-boost transformer and the bus. Each phase device is composed of an uncontrolled rectifier circuit composed of a power diode and a resistance of the parallel IGBT. Considering the transient phenomenon caused by the initial fault of the power network, the full-amplitude compensation strategy is used to calculate the initial value of the equivalent resistance to ensure the stability of the terminal voltage at the time of the voltage drop. At the same time, the optimal control strategy of low power factor is designed to improve the voltage stabilization effect of the protection device in the low power factor working environment. Then, a sliding mode stator flux observer based demagnetization control strategy is proposed. A sliding mode flux observer is used to track the stator flux of DFIG. The DC component of stator flux is obtained by the difference between the observed flux and the AC component obtained by 50Hz bandpass filter. After that, the excitation current of the converter is controlled to establish the leakage magnetic field which is opposite to the DC component of the flux chain, and the attenuation of the transient DC component is accelerated. The simulation results of the demagnetization control strategy verify the effectiveness of the proposed scheme. Finally, an experimental platform consisting of a network-side converter and a resistance protection device for a small wind power system is built, and an experimental study on the low voltage traversal of the voltage sag fault in the power grid is carried out. DSP2812 is used as the main control chip to adjust the duty cycle of the PWM to realize the equivalent resistance adjustment of the serial resistance in the low voltage traversing protection device of the serial resistance. Finally, the three-phase voltage symmetry sag fault is simulated, and the terminal voltage is maintained in the desired range after connecting to the resistance protection device. The validity of the designed resistance protection device is verified, and the correctness of the theoretical research is verified again.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TM614
本文編號：2432516
[Abstract]:Energy crisis and environmental pollution have increased human demand for renewable energy. Wind power generation technology as one of the mainstream new energy has been developed by leaps and bounds in recent years. With the increasing capacity of wind turbine and the increasing permeability of wind power, the interaction between wind power and power grid has attracted extensive attention. DFIG, as one of the two mainstream models at present, has attracted more and more attention. Due to its structural reasons, the overcurrent and overvoltage of the rotor and the voltage fluctuation of the DC bus will occur when the voltage drop occurs in the power network. In serious cases, the unwinding of the fan may also cause the large area paralysis of the power network. Therefore, it is a new research hotspot to ensure the operation of doubly-fed wind turbine under the condition of power grid failure. Taking the doubly-fed wind power system under the condition of voltage sag as the research object, this paper designs an external protection device and a low voltage traversal scheme to optimize the excitation strategy of DFIG. The feasibility of the scheme is verified by simulation and experiment. Firstly, the mathematical model of doubly-fed wind power generation system is built based on PSCAD/EMTDC software, and the working principle and vector control strategy of doubly-fed induction generator are analyzed. Then, the electromagnetic transient characteristics of doubly-fed induction machine under the condition of serious voltage sags are analyzed theoretically and verified by simulation. Secondly, a hardware protection scheme, which is suitable for wide power factor range, is proposed. The designed protection device adopts a three-phase structure, connected in series between the high-voltage side of the fan-boost transformer and the bus. Each phase device is composed of an uncontrolled rectifier circuit composed of a power diode and a resistance of the parallel IGBT. Considering the transient phenomenon caused by the initial fault of the power network, the full-amplitude compensation strategy is used to calculate the initial value of the equivalent resistance to ensure the stability of the terminal voltage at the time of the voltage drop. At the same time, the optimal control strategy of low power factor is designed to improve the voltage stabilization effect of the protection device in the low power factor working environment. Then, a sliding mode stator flux observer based demagnetization control strategy is proposed. A sliding mode flux observer is used to track the stator flux of DFIG. The DC component of stator flux is obtained by the difference between the observed flux and the AC component obtained by 50Hz bandpass filter. After that, the excitation current of the converter is controlled to establish the leakage magnetic field which is opposite to the DC component of the flux chain, and the attenuation of the transient DC component is accelerated. The simulation results of the demagnetization control strategy verify the effectiveness of the proposed scheme. Finally, an experimental platform consisting of a network-side converter and a resistance protection device for a small wind power system is built, and an experimental study on the low voltage traversal of the voltage sag fault in the power grid is carried out. DSP2812 is used as the main control chip to adjust the duty cycle of the PWM to realize the equivalent resistance adjustment of the serial resistance in the low voltage traversing protection device of the serial resistance. Finally, the three-phase voltage symmetry sag fault is simulated, and the terminal voltage is maintained in the desired range after connecting to the resistance protection device. The validity of the designed resistance protection device is verified, and the correctness of the theoretical research is verified again.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TM614
【參考文獻】
相關期刊論文 前10條
1 賀益康;周鵬;;變速恒頻雙饋異步風力發(fā)電系統(tǒng)低電壓穿越技術綜述[J];電工技術學報;2009年09期
2 王勇;張純江;柴秀慧;高俊娥;杜翠;;電網(wǎng)電壓跌落情況下雙饋風力發(fā)電機電磁過渡過程及控制策略[J];電工技術學報;2011年12期
3 張學廣;徐殿國;李偉偉;;雙饋風力發(fā)電機三相短路電流分析[J];電機與控制學報;2008年05期
4 李輝;趙猛;葉仁杰;唐顯虎;劉志詳;;電網(wǎng)故障下雙饋風電機組暫態(tài)電流評估及分析[J];電機與控制學報;2010年08期
5 朱軍衛(wèi),龔春英;逆變器單極性電流SPWM控制與滯環(huán)控制比較[J];電力電子技術;2004年01期
6 胡家兵;孫丹;賀益康;趙仁德;;電網(wǎng)電壓驟降故障下雙饋風力發(fā)電機建模與控制[J];電力系統(tǒng)自動化;2006年08期
7 張學廣;徐殿國;潘偉明;姚春光;;基于電網(wǎng)電壓定向的雙饋風力發(fā)電機滅磁控制策略[J];電力系統(tǒng)自動化;2010年07期
8 劉軍鋒;李葉松;萬淑蕓;;基于U-I模型的感應電機定子磁鏈觀測方法研究[J];電氣傳動;2008年04期
9 王曉蘭;吳東佶;;雙饋發(fā)電機自適應定子磁鏈觀測及參數(shù)辨識[J];電氣傳動;2008年07期
10 郭健;;大規(guī)模風電并入電網(wǎng)對電力系統(tǒng)的影響[J];電氣自動化;2010年01期
本文編號：2432516
本文鏈接：http://sikaile.net/kejilunwen/dianlilw/2432516.html
教材專著
