本文選題：雙饋異步風(fēng)力發(fā)電機(jī)　切入點(diǎn)：DFIG網(wǎng)側(cè)變換器　出處：《長(zhǎng)沙理工大學(xué)》2014年碩士論文

【摘要】：全世界能源危機(jī)的大環(huán)境下,新能源的研究與開(kāi)發(fā)成為研究熱點(diǎn),作為新能源之一的風(fēng)能是一種可再生資源,全球的蘊(yùn)藏量十分豐富。風(fēng)力發(fā)電是一種分布式發(fā)電,風(fēng)力發(fā)電機(jī)并網(wǎng)會(huì)對(duì)電網(wǎng)構(gòu)成沖擊,電網(wǎng)的一些故障也會(huì)對(duì)風(fēng)力發(fā)電機(jī)安全穩(wěn)定運(yùn)行構(gòu)成威脅,在電網(wǎng)發(fā)生故障時(shí),風(fēng)力發(fā)電機(jī)如果具備優(yōu)良的控制性能,將極大地增強(qiáng)機(jī)組的低電壓穿越(LVRT)能力,防止風(fēng)力發(fā)電機(jī)脫離電網(wǎng),保證電網(wǎng)穩(wěn)定運(yùn)行。論文首先介紹了對(duì)稱電網(wǎng)故障下雙饋異步風(fēng)力發(fā)電機(jī)(DFIG)變換器常用的控制策略,目前電網(wǎng)故障大多是不對(duì)稱電網(wǎng)故障,該類故障會(huì)產(chǎn)生負(fù)序分量,在DFIG直流側(cè)產(chǎn)生二倍紋波分量,使用對(duì)稱電網(wǎng)故障下的控制策略來(lái)解決此類新問(wèn)題,因?yàn)榭刂颇Ｐ偷慕⒒鶞?zhǔn)點(diǎn)已經(jīng)發(fā)生改變,所以得到的控制算法不夠準(zhǔn)確,控制會(huì)有較大的誤差甚至危害機(jī)組運(yùn)行。論文推導(dǎo)了靜止abc坐標(biāo)系DFIG數(shù)學(xué)模型和旋轉(zhuǎn)dq坐標(biāo)系DFIG動(dòng)態(tài)數(shù)學(xué)模型,構(gòu)建了不對(duì)稱電網(wǎng)故障時(shí)DFIG網(wǎng)側(cè)變換器數(shù)學(xué)模型,在MATLAB環(huán)境中,驗(yàn)證了該模型建立的正確性。闡述了在該模型下“雙電流閉環(huán)控制策略”的建立過(guò)程。設(shè)計(jì)了不對(duì)稱電網(wǎng)故障時(shí)DFIG網(wǎng)側(cè)變換器性能仿真試驗(yàn),驗(yàn)證加入雙環(huán)策略后,DFIG網(wǎng)側(cè)PWM變換器性能變化,仿真結(jié)果表明,雙環(huán)策略雖然能夠有效提高DFIG“低電壓穿越”性能,但是控制效果有限,存在改進(jìn)空間。論文最后提出基于模糊自適應(yīng)的PID控制器(Fuzzy PID)策略,該策略利用模糊自適應(yīng)技術(shù)對(duì)PID控制器參數(shù)進(jìn)行在線自適應(yīng)調(diào)整,提出基于神經(jīng)網(wǎng)絡(luò)自適應(yīng)的雙電流閉環(huán)控制(NNS-DCLC)策略,該策略利用神經(jīng)網(wǎng)絡(luò)技術(shù)對(duì)PID控制器參數(shù)進(jìn)行實(shí)時(shí)自適應(yīng)調(diào)整,通過(guò)不對(duì)稱電網(wǎng)故障時(shí)DFIG網(wǎng)側(cè)變換器性能仿真試驗(yàn),驗(yàn)證加入改進(jìn)策略后,DFIG網(wǎng)側(cè)PWM變換器性能變化,仿真結(jié)果表明,改進(jìn)策略比傳統(tǒng)雙環(huán)策略,控制性能更好,Fuzzy PID策略較NNS-DCLC策略,電流控制精度更高,動(dòng)態(tài)響應(yīng)時(shí)間更短,對(duì)直流側(cè)電壓波動(dòng)的消除更加有效。
[Abstract]:Under the environment of the global energy crisis, the research and development of new energy becomes a hot spot. As one of the new energy, wind energy is a renewable resource, and the global potential is very rich. Wind power generation is a distributed generation. Grid connection of wind turbines will impact the power grid, and some faults of the grid will also pose a threat to the safe and stable operation of wind turbines. If the power grid failure occurs, if the wind turbine has good control performance, It will greatly enhance the low voltage traversing LVRTs of the unit, prevent the wind turbine from leaving the grid and ensure the stable operation of the grid. Firstly, the paper introduces the common control strategy of the DFIGG converter under the symmetrical power grid fault. At present, most of the power network faults are asymmetric network faults, which will produce negative sequence components, produce double ripple components in the DC side of DFIG, and solve this new problem by using the control strategy under symmetrical power network faults. Because the reference point of the control model has changed, the control algorithm is not accurate enough. In this paper, the static abc coordinate DFIG mathematical model and the rotating DQ coordinate DFIG dynamic mathematical model are derived, and the DFIG grid-side converter mathematical model for asymmetric power network fault is constructed. In the MATLAB environment, the mathematical model of DFIG grid-side converter is constructed. The correctness of the model is verified. The establishment process of "double current closed-loop control strategy" under the model is described. The performance simulation test of DFIG grid-side converter is designed for asymmetric power network faults. The simulation results show that the dual-loop strategy can effectively improve the performance of DFIG "low voltage traversing", but the control effect is limited. Finally, a fuzzy adaptive fuzzy PID-based PID controller strategy is proposed, which adapts the parameters of the PID controller on line using fuzzy adaptive technology. An adaptive dual-current closed-loop control (NNS-DCLC) strategy based on neural network is proposed. The neural network technology is used to adjust the parameters of the PID controller in real time. The simulation test of the performance of the DFIG grid-side converter under asymmetric power network fault is carried out. The simulation results show that the improved strategy is better than the traditional double loop strategy, the control performance is better than the NNS-DCLC strategy, the current control accuracy is higher and the dynamic response time is shorter. The elimination of DC side voltage fluctuation is more effective.
【學(xué)位授予單位】：長(zhǎng)沙理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TM315

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本文編號(hào)：1682914