【摘要】：隨著一次能源的不斷消耗和所造成的環(huán)境污染等問題的日益嚴(yán)重化，，可再生綠色能源的發(fā)展得到了人們越來越多的關(guān)注。光伏發(fā)電被認(rèn)為在是最具有潛力在將來取代一次能源作為電力發(fā)電的新能源形勢。因此，國內(nèi)外學(xué)者們已經(jīng)將運(yùn)用于光伏發(fā)電的并網(wǎng)逆變器技術(shù)當(dāng)作重要研究方向。本文以一臺250kW單級式的三相并網(wǎng)逆變器為基礎(chǔ)，重點(diǎn)研究了并網(wǎng)控制策略中的鎖相環(huán)技術(shù)和并網(wǎng)電流控制技術(shù)。 本文首先研究了單同步旋轉(zhuǎn)dq坐標(biāo)系鎖相法(SSRF-PLL)在電網(wǎng)電壓不平衡條件下存在的鎖相問題。總結(jié)了幾種已有的不平衡鎖相控制技術(shù)，經(jīng)過分析得到鎖相動態(tài)響應(yīng)速度慢的缺點(diǎn)。所以，本文提出了一種基于不平衡電網(wǎng)對稱分量法快速相序分離的鎖相技術(shù)，從而提高了鎖相環(huán)的動態(tài)性能。針對電網(wǎng)不平衡對并網(wǎng)逆變器電流控制技術(shù)的影響，本文通過建立網(wǎng)側(cè)逆變器和功率模型，研究了不平衡條件下的兩種控制目標(biāo)：一是抑制直流輸入電壓脈動；二是抑制并網(wǎng)電流的負(fù)序分量。根據(jù)并網(wǎng)逆變器的自身特點(diǎn)，本文采用了電網(wǎng)電壓正、負(fù)序分量前饋抑制負(fù)序電流的不平衡控制策略。通過仿真驗(yàn)證了本文所采用的不平衡鎖相與電流控制方法的有效性。 本文搭建了一臺250kW的三相并網(wǎng)逆變系統(tǒng)，對系統(tǒng)主電路功率器件參數(shù)進(jìn)行了簡單介紹，并對整個并網(wǎng)的數(shù)字控制結(jié)構(gòu)進(jìn)行了詳細(xì)設(shè)計(jì)。在實(shí)驗(yàn)平臺的基礎(chǔ)上，采用本文所研究的不平衡鎖相控制和電流控制方法在理想電網(wǎng)和不平衡電網(wǎng)下分別進(jìn)行了實(shí)驗(yàn)，并對實(shí)驗(yàn)波形進(jìn)行詳細(xì)分析。實(shí)驗(yàn)結(jié)果，驗(yàn)證了快速不平衡鎖相方法在電網(wǎng)突變條件下能夠迅速跟蹤電網(wǎng)相位信息；也驗(yàn)證了不平衡抑制負(fù)序電流控制技術(shù)在電網(wǎng)不平衡后仍能保證并網(wǎng)電流完全對稱。
[Abstract]:With the continuous consumption of primary energy and the increasing severity of environmental pollution, the development of renewable green energy has received more and more attention. Photovoltaic power generation is considered to be the most potential to replace primary energy as a new energy situation in the future. Therefore, scholars at home and abroad have used grid-connected inverter technology for photovoltaic power generation as an important research direction. Based on a 250kW single-stage three-phase grid-connected inverter, the phase-locked loop technology and grid-connected current control technology in grid-connected control strategy are studied in this paper. In this paper, the phase-locked problem of single synchronous rotating dq coordinate system phase-locked method (SSRF-PLL) under the condition of unbalanced voltage of power grid is studied. Several existing unbalanced phase-locked control techniques are summarized, and the shortcomings of slow phase-locked dynamic response are obtained by analysis. Therefore, a phase-locked technique based on unbalanced power grid symmetric component method for rapid phase sequence separation is proposed in this paper, which improves the dynamic performance of phase-locked loop. In view of the influence of grid imbalance on the current control technology of grid-connected inverter, this paper studies two kinds of control objectives under unbalanced condition by establishing grid-side inverter and power model: one is to suppress DC input voltage pulsation; The second is to suppress the negative sequence component of grid-connected current. According to the characteristics of grid-connected inverter, this paper adopts the unbalanced control strategy of voltage positive and negative sequence component feedforward to suppress negative sequence current. The effectiveness of the unbalanced phase-locked and current control method used in this paper is verified by simulation. In this paper, a three-phase grid-connected inverter system of 250kW is built, the parameters of the main circuit power device of the system are briefly introduced, and the whole digital control structure of the grid-connected system is designed in detail. On the basis of the experimental platform, the unbalanced phase-locked control and current control methods studied in this paper are used to carry out experiments in ideal power grid and unbalanced power grid respectively, and the experimental waveforms are analyzed in detail. The experimental results verify that the fast unbalanced phase-locked method can quickly track the phase information of the power grid under the condition of sudden change of the power grid, and also verify that the negative sequence current control technology of unbalanced suppression can still ensure the complete symmetry of the grid-connected current after the imbalance of the power grid.
【學(xué)位授予單位】：南京航空航天大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TM464

【參考文獻(xiàn)】

相關(guān)期刊論文 前9條

1 周林;張林強(qiáng);李懷花;杜金其;龍崦平;廖波;;光伏并網(wǎng)逆變器負(fù)序分量補(bǔ)償法控制策略[J];高電壓技術(shù);2013年05期

2 王萬寶;張犁;胡海兵;邢巖;;三相電壓不平衡條件下改進(jìn)的鎖相技術(shù)[J];電力電子技術(shù);2013年07期

3 溫旭輝;;汽車電氣化進(jìn)程中的電機(jī)驅(qū)動技術(shù)[J];電力電子;2011年01期

4 ;中國光伏發(fā)電的技術(shù)現(xiàn)狀及展望[J];可再生能源;2002年03期

5 魏克新;汪水明;;電網(wǎng)不平衡條件下PWM整流器最優(yōu)化控制策略研究[J];現(xiàn)代電力;2009年05期

6 孔雪娟;羅f ;彭力;康勇;;基于周期控制的逆變器全數(shù)字鎖相環(huán)的實(shí)現(xiàn)和參數(shù)設(shè)計(jì)[J];中國電機(jī)工程學(xué)報;2007年01期

7 張強(qiáng);張崇巍;張興;謝震;;風(fēng)力發(fā)電用大功率并網(wǎng)逆變器研究[J];中國電機(jī)工程學(xué)報;2007年16期

8 耿強(qiáng);夏長亮;閻彥;陳煒;;電網(wǎng)電壓不平衡情況下PWM整流器恒頻直接功率控制[J];中國電機(jī)工程學(xué)報;2010年36期

9 徐友;鄭建勇;梅軍;姚磊;;負(fù)序電壓前饋補(bǔ)償?shù)娜喙夥孀兤鞑黄胶鈫沃芸刂撇呗訹J];中國電機(jī)工程學(xué)報;2012年36期

本文編號：2490346