本文選題：并網(wǎng)逆變器　切入點：電網(wǎng)　出處：《哈爾濱工業(yè)大學》2015年碩士論文　論文類型：學位論文

【摘要】：在分布式新能源發(fā)電大量增加及電網(wǎng)智能化的發(fā)展趨勢下,電網(wǎng)系統(tǒng)的構(gòu)成及其動態(tài)特性變得愈加復雜,導致其穩(wěn)定性更加容易受到影響。新能源發(fā)電多數(shù)通過逆變器并網(wǎng),系統(tǒng)中各逆變器之間存在不同程度的差異,引起不同形式的兼容性問題。其中由于阻抗不匹配而引起的諧波振蕩問題尤為關(guān)鍵,嚴重時可導致整個發(fā)電網(wǎng)絡(luò)的癱瘓。對于分布式發(fā)電系統(tǒng)中某一獨立逆變器來說,除自身外其他逆變器等效總體阻抗對其穩(wěn)定性的影響可通過電網(wǎng)阻抗反映。因此,本課題以電網(wǎng)阻抗辨識為基礎(chǔ),對并網(wǎng)逆變器的穩(wěn)定性進行分析,對保證電網(wǎng)系統(tǒng)的穩(wěn)定運行具有一定的意義。首先對電網(wǎng)阻抗在線辨識的實現(xiàn)方案進行了研究,分析了脈沖響應(yīng)分析法的基本原理,對其擾動注入和響應(yīng)分析部分進行了具體設(shè)計,驗證了其所具有的快速性及寬頻帶特性。在仿真中對電網(wǎng)阻抗在線辨識方案進行了驗證,分析了辨識過程中的響應(yīng)波形及辨識結(jié)果的影響因素。利用諧波線性化方法建立了逆變器控制系統(tǒng)中鎖相環(huán)及電流控制的小信號模型,結(jié)合逆變器主電路平均模型,得到了逆變器輸出阻抗的頻域模型,并以頻率掃描的方式在仿真中對其進行了驗證。確定了逆變器輸出阻抗的影響因素,為后續(xù)的穩(wěn)定性分析奠定了基礎(chǔ)。利用電網(wǎng)阻抗及逆變器輸出阻抗模型,采用基于阻抗的穩(wěn)定性分析方法,分析了電網(wǎng)阻抗對并網(wǎng)逆變器穩(wěn)定性的影響。根據(jù)穩(wěn)定性分析結(jié)果及逆變器輸出阻抗的影響因素,確定了解決諧振問題的方法。通過仿真,將穩(wěn)定性分析理論與逆變器系統(tǒng)的時域響應(yīng)聯(lián)系到一起,對分析方法做出了驗證。最后建立了并網(wǎng)逆變器穩(wěn)定性分析實驗平臺,并在實驗平臺中進行了電網(wǎng)阻抗在線辨識及穩(wěn)定性分析實驗,對各項研究內(nèi)容做出了驗證。
[Abstract]:With the increase of distributed new energy generation and the development trend of intelligent power grid, the composition and dynamic characteristics of power system become more complex, which makes its stability more vulnerable. There are different degrees of differences among the inverters in the system, which cause different kinds of compatibility problems, among which the harmonic oscillation caused by impedance mismatch is particularly critical. For an independent inverter in a distributed generation system, the effect of the equivalent total impedance of the inverter other than itself on its stability can be reflected by the grid impedance. Based on grid impedance identification, this paper analyzes the stability of grid-connected inverter, which has a certain significance to ensure the stable operation of power system. Firstly, the realization scheme of on-line identification of grid impedance is studied. The basic principle of impulse response analysis is analyzed, and its disturbance injection and response analysis are designed to verify its rapidity and broadband characteristics. In the simulation, the on-line identification scheme of power network impedance is verified. The response waveform in the identification process and the influencing factors of the identification results are analyzed. The small signal model of phase-locked loop and current control in inverter control system is established by using harmonic linearization method, and combined with the average model of inverter main circuit. The frequency domain model of the output impedance of the inverter is obtained, and it is verified in the simulation by frequency scanning. The influence factors of the output impedance of the inverter are determined. It lays a foundation for the subsequent stability analysis. Using the power grid impedance and inverter output impedance model, the impedance based stability analysis method is adopted. The influence of grid impedance on the stability of grid-connected inverter is analyzed. According to the results of stability analysis and the influence factors of inverter output impedance, the method of solving resonance problem is determined. The stability analysis theory is combined with the time-domain response of the inverter system, and the analysis method is verified. Finally, a grid-connected inverter stability analysis experimental platform is established. The on-line identification and stability analysis experiments of power system impedance are carried out on the experimental platform, and the research contents are verified.
【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】：2015
【分類號】：TM464

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相關(guān)期刊論文 前1條

1 許德志;汪飛;阮毅;毛華龍;張巍;楊影;;多逆變器并網(wǎng)系統(tǒng)輸出阻抗建模與諧波交互[J];電機與控制學報;2014年02期

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本文編號：1601665