本文關(guān)鍵詞： 中點箝位型 零序電壓注入 雙調(diào)制波 混合調(diào)制 載波變幅調(diào)制　出處：《北京交通大學》2017年碩士論文　論文類型：學位論文

【摘要】：三電平中點箝位型(Neutral-Point-Clamped,NPC)變換器具有結(jié)構(gòu)簡單,開關(guān)應(yīng)力小,開關(guān)損耗少,電磁干擾低等優(yōu)點,但其固有的中點電壓不平衡的問題限制了這一拓撲在實際工業(yè)生產(chǎn)中的應(yīng)用。本文主要針對三電平NPC變換器中點電壓不平衡的問題進行研究。詳細分析了三電平NPC變換器的工作原理,研究了變換器直流側(cè)中點電壓平衡機理。在此基礎(chǔ)上,深入分析了零序電壓和中點平均電流之間的關(guān)系,分三種情況討論了零序電壓的取值限制對中點平均電流的影響。零序電壓注入法可以很好地控制三電平NPC變換器直流側(cè)的中點平衡,具有原理簡單、計算簡便等優(yōu)點,但是在調(diào)制系數(shù)較大或者功率因數(shù)較低的情況下存在不可消除的低頻波動。雙調(diào)制波法可以在全范圍內(nèi)消除中點波動,但會造成開關(guān)頻率的增大和諧波性能惡化。針對零序電壓法和雙調(diào)制波法的優(yōu)勢和劣勢,提出了零序電壓注入和雙調(diào)制波混合的調(diào)制方法,這種混合調(diào)制方法達到了在消除低頻波動的同時又能最大程度上降低開關(guān)頻率和保持諧波性能的目的。深入研究了載波變幅調(diào)制對三電平NPC變換器輸出參考電壓的影響,得出了載波幅值隨著直流側(cè)上下電容電壓成比例變化時三電平NPC變換器能夠輸出理想基波幅值的參考電壓和保持輸出參考電壓伏秒平衡的結(jié)論。在此基礎(chǔ)上,提出了基于載波變幅求解零序電壓的中點電壓平衡控制方法。該方法首先將載波幅值按照直流側(cè)上下電容電壓成比例變化,保持輸出參考電壓相關(guān)特性,然后根據(jù)控制直流側(cè)中點電壓平衡的原理向三相參考電壓中注入合適的零序電壓,控制直流側(cè)中點電壓平衡。這種控制策略不僅能夠使直流側(cè)中點電壓達到平衡,而且還能保持輸出參考電壓的相關(guān)特性。搭建了三電平NPC變換器實驗平臺,并對本文所提出的控制策略進行了實驗。實驗結(jié)果證明了本文所提出的中點電壓平衡控制策略的正確性和有效性。
[Abstract]:Three-level Neutral-Point-Clampedn NPC (NPC) converter has the advantages of simple structure, low switching stress, low switching loss and low electromagnetic interference. However, the inherent neutral point voltage imbalance has limited the application of this topology in practical industrial production. In this paper, the unbalanced neutral point voltage of three-level NPC converter is studied in detail. The principle of level NPC converter. The mechanism of neutral voltage balance in DC side is studied, and the relationship between zero-sequence voltage and midpoint average current is analyzed. The effect of zero sequence voltage limit on the average neutral current is discussed in three cases. The zero sequence voltage injection method can well control the neutral point balance in the DC side of the three-level NPC converter, and the principle is simple. It is easy to calculate, but there are some low frequency waves in the case of high modulation coefficient or low power factor. The double modulation wave method can eliminate the midpoint fluctuation in the whole range. However, the switching frequency will increase and the harmonic performance will deteriorate. Aiming at the advantages and disadvantages of zero-sequence voltage method and dual-modulation wave method, a hybrid modulation method of zero-sequence voltage injection and dual-modulation wave is proposed. The hybrid modulation method can reduce the switching frequency and maintain the harmonic performance at the same time as eliminating the low frequency fluctuation. The output reference of the three-level NPC converter based on the carrier variable amplitude modulation is deeply studied. The effect of voltage. It is concluded that the three-level NPC converter can output the reference voltage of the ideal fundamental amplitude and keep the balance of the output reference voltage in volts when the carrier amplitude varies proportionally with the voltage of the DC side up and down. On this basis, the conclusion is drawn that the three-level NPC converter can output the reference voltage of the ideal fundamental amplitude. . A midpoint voltage balance control method based on carrier amplitude-varying solution to zero sequence voltage is proposed. Firstly, the carrier amplitude is proportional to the upper and lower capacitance voltage of the DC side to maintain the output reference voltage-related characteristics. Then according to the principle of controlling the midpoint voltage balance at the DC side, a suitable zero-sequence voltage is injected into the three-phase reference voltage. This control strategy can not only balance the neutral voltage of DC side, but also maintain the characteristics of output reference voltage. A three-level NPC converter experimental platform is built. The experimental results show that the proposed midpoint voltage balance control strategy is correct and effective.
【學位授予單位】：北京交通大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TM46

【參考文獻】

相關(guān)期刊論文 前10條

1 余世瑤;王琛琛;辛宏亮;李治佟;;考慮三電平中點鉗位型變換器中點電壓波動抑制的混合調(diào)制方法[J];電工技術(shù)學報;2016年S1期

2 曾翔君;張曉;楊永兵;陳發(fā);楊旭;;具有飛跨電容輔助橋臂的三電平中點鉗位逆變器方案[J];電力系統(tǒng)自動化;2014年08期

3 王奎;鄭澤東;李永東;馮江華;劉可安;;基于五電平有源中點鉗位型雙PWM變換器的異步電機矢量控制系統(tǒng)[J];電工技術(shù)學報;2014年02期

4 劉戰(zhàn);譚國俊;李探;李浩;;有源中點箝位型五電平整流器DPC-SVM控制研究[J];電力電子技術(shù);2013年09期

5 王琛琛;張燦;游小杰;;基于雙調(diào)制波的中點電壓平衡算法[J];電工技術(shù)學報;2012年03期

6 洪峰;劉苗;嵇保健;王成華;;一種飛跨電容型多電平逆變器電容建壓方法[J];中國電機工程學報;2012年06期

7 石勇;;電容箝位型3電平復(fù)合全橋DC/DC變換器[J];電力電子技術(shù);2011年11期

8 李小凡;;飛跨電容型多電平變流器的多載波PWM方法[J];機電工程技術(shù);2011年04期

9 景巍;譚國俊;趙張飛;;有源鉗位三電平變頻器調(diào)制策略及損耗分析[J];電氣傳動;2011年02期

10 孫運全;尹強;盛吉;潘文婷;;級聯(lián)H橋型多電平變換器載波帶頻率變化的PWM方法的研究[J];低壓電器;2010年03期

相關(guān)博士學位論文 前1條

1 胡存剛;多電平二極管箝位型逆變器PWM控制方法及相關(guān)問題的研究[D];合肥工業(yè)大學;2008年

相關(guān)碩士學位論文 前3條

1 曾磊樂;T型三電平逆變器的中點電位控制算法研究[D];電子科技大學;2015年

2 張珍珍;基于載波的三電平逆變器中點電位控制技術(shù)的研究[D];太原理工大學;2015年

3 張燦;二極管箝位型三電平變換器母線電容電壓控制策略研究[D];北京交通大學;2011年

，

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