【摘要】：隨著分布式發(fā)電系統(tǒng)的迅速發(fā)展,并網(wǎng)逆變器得到廣泛應(yīng)用。由于在地處偏遠(yuǎn)的分布式發(fā)電系統(tǒng)中,長距離的傳輸線以及大量變壓裝置的存在給電網(wǎng)帶來一個(gè)不可忽略的等效阻抗,使得電網(wǎng)呈弱電網(wǎng)特性。因此,弱電網(wǎng)和并網(wǎng)逆變器之間構(gòu)成交互式系統(tǒng),電網(wǎng)阻抗將會(huì)對(duì)并網(wǎng)逆變器控制系統(tǒng)的穩(wěn)定性造成一定的影響。本文主要研究了弱電網(wǎng)條件下電網(wǎng)阻抗對(duì)并網(wǎng)逆變器穩(wěn)定性的影響。首先,對(duì)基于LCL濾波的并網(wǎng)逆變器控制系統(tǒng)進(jìn)行小信號(hào)建模,給出了比例諧振(PR)調(diào)節(jié)器參數(shù)設(shè)計(jì)方案。以電感-電阻(L-R)串聯(lián)模型作為弱電網(wǎng)模型,分析了電網(wǎng)阻抗所帶來的逆變器控制系統(tǒng)的穩(wěn)定性問題。然后,分析了幾種常用的阻抗測(cè)量方法,并選取了小信號(hào)注入法作為弱電網(wǎng)阻抗的在線測(cè)量手段。同時(shí),論文對(duì)無源阻尼和有源阻尼兩種常用的諧振抑制方案進(jìn)行了進(jìn)一步的分析,在此基礎(chǔ)上引出了混合阻尼抑制方案,并與電網(wǎng)阻抗測(cè)量技術(shù)相結(jié)合,組成了基于混合阻尼的并網(wǎng)逆變器自適應(yīng)控制策略,使得并網(wǎng)逆變器在各種電網(wǎng)阻抗條件下都可以保持較為優(yōu)良的系統(tǒng)特性。最后論文根據(jù)系統(tǒng)的要求,設(shè)計(jì)并搭建了一臺(tái)基于數(shù)字控制的1.5kW并網(wǎng)逆變器實(shí)驗(yàn)平臺(tái),給出了硬件和軟件設(shè)計(jì)過程,并在此平臺(tái)上完成了電網(wǎng)阻抗對(duì)并網(wǎng)逆變器穩(wěn)定性影響實(shí)驗(yàn),驗(yàn)證了混合阻尼自適應(yīng)控制方案的正確性和可行性。
[Abstract]:With the rapid development of distributed generation system, grid-connected inverter is widely used. In the remote distributed generation system, the existence of long distance transmission lines and a large number of voltage transformers brings a non-negligible equivalent impedance to the power network, which makes the power network show weak network characteristics. Therefore, there is an interactive system between the weak grid and grid-connected inverter, and the impedance of the grid will affect the stability of the grid-connected inverter control system. In this paper, the influence of grid impedance on the stability of grid-connected inverter is studied. Firstly, the control system of grid-connected inverter based on LCL filter is modeled with small signal, and the parameter design scheme of proportional resonant (PR) regulator is presented. Taking the inductance resistance (L-R) series model as the weak grid model, the stability of the inverter control system caused by the power grid impedance is analyzed. Then, several commonly used impedance measurement methods are analyzed, and the small signal injection method is selected as the on-line measurement method of the impedance of weak electric network. At the same time, two common resonant suppression schemes, passive damping and active damping, are further analyzed in this paper. On this basis, a hybrid damping suppression scheme is proposed, which is combined with the impedance measurement technology of power network. The adaptive control strategy of grid-connected inverter based on hybrid damping is formed, which makes the grid-connected inverter keep excellent system characteristics under various grid impedance conditions. Finally, according to the requirements of the system, an experimental platform of 1.5kW grid-connected inverter based on digital control is designed and built, and the design process of hardware and software is given. On this platform, the influence of grid impedance on the stability of grid-connected inverter is completed, and the correctness and feasibility of hybrid damping adaptive control scheme are verified.
【學(xué)位授予單位】：南京航空航天大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TM464

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 劉飛;段善旭;查曉明;;基于LCL濾波器的并網(wǎng)逆變器雙環(huán)控制設(shè)計(jì)[J];中國電機(jī)工程學(xué)報(bào);2009年S1期

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本文編號(hào)：2249302