發(fā)布時(shí)間：2018-07-02 19:51

  本文選題：電網(wǎng)不平衡 + 電網(wǎng)電壓跌落�。� 參考：《電子科技大學(xué)》2014年碩士論文

【摘要】：隨著大功率開(kāi)關(guān)器件和數(shù)字信號(hào)處理器技術(shù)的進(jìn)步,分布式發(fā)電系統(tǒng)得到廣泛應(yīng)用與發(fā)展,彌補(bǔ)了傳統(tǒng)發(fā)電能源的不足。實(shí)際電網(wǎng)不是理想的,是個(gè)動(dòng)態(tài)復(fù)雜的系統(tǒng),分布式發(fā)電系統(tǒng)在電網(wǎng)故障下要保持正常并網(wǎng)工作又要保證電能質(zhì)量,因此要求逆變器在電網(wǎng)不平衡故障情況下保證注入電網(wǎng)電能質(zhì)量,在電網(wǎng)電壓跌落故障下不脫網(wǎng),并抑制瞬間大電流沖擊,保護(hù)設(shè)備器件不受損壞。本文對(duì)電網(wǎng)故障下逆變器并網(wǎng)控制策略進(jìn)行了深入的研究。(1)電網(wǎng)故障下的電壓矢量的研究和分析。研究分析電網(wǎng)電壓不平衡故障時(shí)電壓正序、負(fù)序、零序分量的提取算法,為第三章單同步坐標(biāo)系控制結(jié)構(gòu)的改進(jìn)提供依據(jù);研究電網(wǎng)電壓跌落故障時(shí)電壓的分類及派生,為第四章低電壓穿越控制算法奠定基礎(chǔ),簡(jiǎn)化了控制策略的分析。(2)對(duì)電網(wǎng)不平衡故障下的并網(wǎng)逆變器控制策略進(jìn)行分析。首先在電網(wǎng)電壓理想條件下對(duì)并網(wǎng)逆變器進(jìn)行建模分析,引出電網(wǎng)電壓不平衡條件下對(duì)逆變器傳統(tǒng)單同步坐標(biāo)系控制結(jié)構(gòu)的影響,得出傳統(tǒng)的單同步坐標(biāo)系PI控制器結(jié)構(gòu)無(wú)法同時(shí)跟蹤正序分量和負(fù)序分量,必然會(huì)有二倍基波頻率振蕩的結(jié)論;然后以此結(jié)論為依據(jù),提出適應(yīng)電網(wǎng)不平衡故障的控制結(jié)構(gòu)—雙同步坐標(biāo)系PI控制結(jié)構(gòu),可以消除二倍基波頻率振蕩的影響;最后根據(jù)控制目標(biāo)和用戶需求的不同,提出不同的控制策略,滿足注入電網(wǎng)電流平衡或功率平衡的需求,仿真證實(shí)理論分析的有效性。(3)對(duì)電網(wǎng)電壓跌落故障下并網(wǎng)逆變器的低電壓穿越控制算法進(jìn)行研究分析。針對(duì)電網(wǎng)電壓跌落故障時(shí)并網(wǎng)逆變器的控制難點(diǎn)分別進(jìn)行研究分析并提出控制策略解決。通過(guò)雙同步坐標(biāo)系解耦鎖相環(huán)得到dv?的瞬時(shí)值來(lái)檢測(cè)電網(wǎng)電壓狀態(tài)及跌落深度;并對(duì)電網(wǎng)電壓跌落期間注入電網(wǎng)功率進(jìn)行合理分配與控制,防止過(guò)流;提出瞬時(shí)前饋控制策略抑制電網(wǎng)電壓跌落瞬間的大電流沖擊,通過(guò)理論分析電流沖擊的必然性和瞬時(shí)前饋控制的有效性,通過(guò)仿真實(shí)驗(yàn)證實(shí)低電壓穿越控制算法的有效性,在德陽(yáng)某公司逆變器調(diào)試區(qū)50kW儲(chǔ)能逆變器設(shè)備上進(jìn)行低電壓穿越實(shí)驗(yàn),通過(guò)項(xiàng)目認(rèn)證和驗(yàn)收,并完成零電壓穿越實(shí)驗(yàn)。
[Abstract]:With the development of high power switchgear and digital signal processor (DSP), distributed power generation system has been widely used and developed, which makes up for the shortage of traditional generation energy. The actual power grid is not ideal, it is a dynamic and complex system, distributed generation system should keep normal grid connection and ensure power quality. Therefore, the inverter is required to ensure the quality of power injected into the power network under the condition of unbalanced fault of the power network, not to get rid of the grid in the case of voltage drop fault, to suppress the instantaneous high current shock, and to protect the device from damage. In this paper, the inverter grid-connected control strategy under power network fault is deeply studied. (1) the research and analysis of voltage vector in power network fault. In order to improve the control structure of single synchronous coordinate system in chapter 3, the extraction algorithm of voltage positive sequence, negative sequence and zero sequence component in unbalanced voltage fault of power network is studied, and the classification and derivation of voltage in voltage sag fault are studied. It lays a foundation for the control algorithm of low voltage traversing in chapter 4 and simplifies the analysis of control strategy. (2) the control strategy of grid-connected inverter under unbalanced power network fault is analyzed. Firstly, the modeling and analysis of grid-connected inverter under ideal grid voltage conditions are carried out, and the influence of grid voltage imbalance on the traditional single-synchronous coordinate system control structure of inverter is introduced. It is concluded that the traditional Pi controller structure of single synchronous coordinate system can not track the positive and negative sequence components simultaneously, and there is bound to be a double fundamental frequency oscillation, which is based on the conclusion that the Pi controller structure can not track the positive and negative sequence components at the same time. The double synchronous coordinate system Pi control structure, which adapts to the unbalanced fault of power network, is proposed, which can eliminate the influence of the frequency oscillation of double fundamental wave. Finally, according to the difference of control objectives and users' demands, different control strategies are proposed. The simulation results show that the theoretical analysis is effective. (3) the low voltage traversal control algorithm of grid-connected inverter under voltage sag fault is studied and analyzed. The control difficulties of grid-connected inverter during voltage drop fault are studied and analyzed, and the control strategy is proposed. By decoupling phase locked loop in double synchronous coordinate system, the DVD? To detect the voltage state and the drop depth of the power grid, to distribute and control the power injected into the power network during the voltage drop, to prevent the overcurrent, and to put forward the instantaneous feedforward control strategy to restrain the large current shock at the moment of the voltage drop. Through the theoretical analysis of the inevitability of current shock and the effectiveness of instantaneous feedforward control, the effectiveness of the low voltage traversing control algorithm is verified by simulation experiments. The low voltage traversing experiment was carried out on 50kW energy storage inverter equipment of a company in Deyang, and the zero voltage traversing experiment was completed through project certification and acceptance.
【學(xué)位授予單位】：電子科技大學(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 袁曉玲;宋鵬飛;范發(fā)靖;陳宇;;光伏逆變器低電壓穿越控制策略[J];電力電子技術(shù);2013年03期

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本文編號(hào)：2090735