電網(wǎng)故障下并網(wǎng)逆變器的運(yùn)行仿真研究

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摘要 近些年來(lái)我國(guó)風(fēng)電、太陽(yáng)能等新能源發(fā)展迅猛的同時(shí)，新能源發(fā)電機(jī)組大規(guī)模地引入電網(wǎng)對(duì)電網(wǎng)的穩(wěn)定性是個(gè)嚴(yán)峻的考驗(yàn)，新能源發(fā)電機(jī)組對(duì)于電力系統(tǒng)造成的影響也已經(jīng)成為諸多學(xué)者和電力系統(tǒng)專(zhuān)家們關(guān)注的一個(gè)研究熱點(diǎn)。針對(duì)大規(guī)模引入新能源的現(xiàn)狀，當(dāng)前新能源發(fā)電機(jī)組對(duì)電力系統(tǒng)影響的研究主要關(guān)注于電網(wǎng)電壓跌落情況下的影響。根據(jù)新能源發(fā)電機(jī)組運(yùn)行規(guī)則，當(dāng)電網(wǎng)發(fā)生外部故障時(shí)，發(fā)電機(jī)組不能立刻脫網(wǎng)運(yùn)行，因?yàn)樵陔娋W(wǎng)發(fā)生故障的情況下，切除大容量的發(fā)電機(jī)組會(huì)危及整個(gè)電力系統(tǒng)，因此必須要研究在電網(wǎng)發(fā)生故障時(shí)，如何保證發(fā)電機(jī)組具備與電網(wǎng)的持續(xù)運(yùn)行能力。
并網(wǎng)逆變器作為能量回饋的主要部件，擔(dān)負(fù)著將系統(tǒng)輸出的直流電逆變?yōu)榻涣麟婐伻腚娋W(wǎng)的重任，因此對(duì)其在電網(wǎng)故障下的運(yùn)行展開(kāi)深入的研究具有非常重要的意義。
本畢業(yè)設(shè)計(jì)擬對(duì)并網(wǎng)逆變器的控制策略展開(kāi)研究，通過(guò)SIMULINK軟件模擬并網(wǎng)逆變器在不同電網(wǎng)故障下并網(wǎng)逆變器的運(yùn)行，如三相對(duì)稱(chēng)電壓跌落和單相電壓跌落等電網(wǎng)故障下的運(yùn)行，總結(jié)出并網(wǎng)逆變器在電網(wǎng)故障下運(yùn)行時(shí)各項(xiàng)參數(shù)的變化規(guī)律，同時(shí)根據(jù)不同電壓跌落程度對(duì)電網(wǎng)進(jìn)行一定的無(wú)功補(bǔ)償，使得并網(wǎng)逆變器電流輸出穩(wěn)定。仿真結(jié)果表明，不同的電網(wǎng)故障對(duì)并網(wǎng)逆變器的運(yùn)行都有較大的影響。因此，必須采取相應(yīng)的控制策略來(lái)減小電網(wǎng)故障的影響，通過(guò)對(duì)電網(wǎng)輸送一定的無(wú)功補(bǔ)償可以減小電網(wǎng)故障的影響，甚至消除影響。

關(guān)鍵詞：并網(wǎng)逆變器；SVPWM；電網(wǎng)故障；控制策略；無(wú)功補(bǔ)償

The Research on the grid-connected inverter operating under grid failures
Abstract In recent years, the new energy of wind power , solar energy and other has been developing rapidly , while these new energy generators are a severe test to the stability of the grid , the impact of new energy generators for power system has leaded many scholars and the power system experts to focus on the hot research topic concerns. For large-scale introduction of new energy , the current study of the impact of new energy turbine generators for power system mainly focuses on the influence of the grid voltage drop. Based on the current rules for the operation of new energy generators, when the external grid failure occurs, generators can not grid off immediately, Because in case of the grid failure the removal of large capacity generators would endanger the entire power system. Therefore,experts must study how to ensure that generators and the grid have the ability to continue to run normally.
The grid-connected inverter is the main component of the energy feedback, which is responsible for transforming the output of the DC to the AC, so the research on the grid-connected inverter operating under grid failures is importantly significant.
I intends to study the control strategy of the grid-connected inverter in the graduation project. I will use simulink simulation software to simulate the operation of the grid-connected inverter under different grid failures , such as three-phase and single-phase voltage drop, etc. I will also summarize various parameters variation of the grid-connected inverter under different grid failures. At the same time, depending on the voltage drop on the grid , a certain degree of reactive power is poured to maintain grid electric current stability. Finally, the simulation results show that the effect of the grid failures for the grid-connected inverter operation is serious. Therefore, we must take the appropriate control strategies to reduce the impact of the grid failures. A certain degree of reactive power is poured into the grid, which can reduce the impact of the grid failures, or even eliminate the impact.
Key words: the grid-connected inverter, the grid failures, the control strategies, reactive compensation.

目錄
第一章 緒論 1
1.1 課題研究背景 1
1.2 并網(wǎng)逆變器國(guó)內(nèi)外研究現(xiàn)狀 2
1.3 分布式發(fā)電系統(tǒng)并網(wǎng)標(biāo)準(zhǔn) 3
1.4 課題研究意義 6
1.5 主要研究?jī)?nèi)容及論文結(jié)構(gòu)安排 7
第二章 并網(wǎng)逆變器簡(jiǎn)介及控制原理…………………………………8
2.1 并網(wǎng)逆變器的技術(shù)現(xiàn)狀 8
2.1.1 并網(wǎng)逆變器的原理 8
2.1.2 并網(wǎng)逆變器拓?fù)浼胺诸?lèi) 9
2.1.3 并網(wǎng)逆變器的控制技術(shù) 11
2.1.3.1 并網(wǎng)逆變器控制目的…………………….………………11
2.1.3.2 并網(wǎng)逆變器控制策略………..…………………………..12
2.2 并網(wǎng)逆變器的數(shù)學(xué)模型 14
2.3 SVPWM的控制算法 16
2.3.1 SVPWM的基本原理 16
2.3.2 SVPWM的算法 18
2.3.2.1 3s/2r/2坐標(biāo)轉(zhuǎn)換……………………….…………………...18
2.3.2.2 扇區(qū)判斷方法………………………...……………………22
2.3.2.3 扇區(qū)內(nèi)矢量作用時(shí)間的算法…………………………..….22
2.3.2.4 矢量切換點(diǎn)算法………………………………...…………23
2.4 本章小結(jié)………………………..…………………….…………………....25
第三章 電網(wǎng)電壓故障下并網(wǎng)逆變器仿真建模與驗(yàn)證 26
3.1 電網(wǎng)電壓跌落故障類(lèi)型 26
3.2 并網(wǎng)逆變器仿真模型構(gòu)建 28
3.3 網(wǎng)側(cè)正常情況下仿真結(jié)果 32
3.4 網(wǎng)側(cè)不同故障時(shí)仿真結(jié)果 33
3.4.1 網(wǎng)側(cè)三相短路故障下并網(wǎng)逆變器仿真 34
3.4.2 網(wǎng)側(cè)單相故障故障下并網(wǎng)逆變器仿真 35
3.4.3 網(wǎng)側(cè)故障時(shí)無(wú)功補(bǔ)償并網(wǎng)逆變器仿真 38
3.5 本章小結(jié)…………………………………………………………..……….39
第四章 總結(jié)與展望 40
4.1 全文總結(jié) 40
4.2 論文展望 40
致謝 41
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