本文關鍵詞： 多脈波整流 直流側諧波抑制 諧波畸變率 電壓不平衡度　出處：《中國礦業(yè)大學》2016年碩士論文　論文類型：學位論文

【摘要】：大功率整流電路會給電網(wǎng)帶來大量的諧波污染,多脈波整流系統(tǒng)能很好的解決上述問題,但該系統(tǒng)并不能完全消除網(wǎng)側低次諧波,為達到更好的諧波抑制效果,本文研究了一種應用于隔離場合的基于常規(guī)18脈波整流系統(tǒng)主電路拓撲結構的帶單相逆變器的網(wǎng)側諧波抑制系統(tǒng)。本文從常規(guī)12脈波整流系統(tǒng)出發(fā),根據(jù)系統(tǒng)直流側變量與交流側變量之間的轉換關系,計算出系統(tǒng)網(wǎng)側電流和系統(tǒng)直流側電壓傅里葉表達式�；谥绷鱾戎C波抑制原理,本文分別討論了直流側統(tǒng)一調制和直流側電壓可調這兩種直流側諧波抑制技術,并通過仿真分別驗證了這兩種方法對網(wǎng)側電流諧波的抑制效果。本文在18脈波整流系統(tǒng)的基礎上,研究了一種基于單相逆變器的直流側諧波抑制系統(tǒng)。單相逆變器產(chǎn)生交流輔助方波電壓,通過高頻變壓器耦合到系統(tǒng)直流側,改進直流側電流波形,使得網(wǎng)側電流諧波得到抑制,并與常規(guī)18脈波整流系統(tǒng)輸入電流及輸出電壓進行比較。多脈波整流系統(tǒng)輸出電壓不平衡的原因主要有網(wǎng)側電壓不平衡和整流變壓器結構不對稱。首先,本文研究了整流變壓器繞組匝數(shù)不對稱對系統(tǒng)輸出電壓不平衡的影響,根據(jù)三角形正余弦定理計算出它們之間的表達式,并通過仿真繪制出它們之間的波形示意圖;其次,本文研究了變壓器在結構對稱的情況下,系統(tǒng)三相輸入電壓不平衡與整流變壓器輸出電壓不平衡度之間的定量關系;最后研究了在各種不平衡條件下,網(wǎng)側電流總諧波畸變率的變化規(guī)律,并與仿真結果進行比較。最后搭建了18脈波整流系統(tǒng)平臺,給出了主電路器件選型的具體步驟及控制系統(tǒng)軟件實現(xiàn)流程圖。并對18脈波直流側諧波抑制系統(tǒng)進行調試,完成實驗驗證。
[Abstract]:The high-power rectifier circuit will bring a lot of harmonic pollution to the power network, the multi-pulse rectifier system can solve the above problems well, but the system can not completely eliminate the low-order harmonics of the grid side, in order to achieve better harmonic suppression effect. A grid-side harmonic suppression system with single-phase inverter based on the main circuit topology of conventional 18-pulse rectifier system is studied in this paper. According to the conversion relationship between DC side variables and AC side variables, Fourier expressions of system network side current and system DC side voltage are calculated, based on the principle of DC side harmonic suppression. In this paper, two kinds of DC side harmonic suppression techniques are discussed, which are DC side unified modulation and DC side voltage adjustable. The simulation results show that these two methods can suppress the current harmonics on the grid side. This paper is based on the 18 pulse rectifier system. A DC side harmonic suppression system based on single-phase inverter is studied. The single-phase inverter generates AC auxiliary square wave voltage, which is coupled to the DC side of the system by high-frequency transformer to improve the DC side current waveform. The current harmonics on the grid side are suppressed. And compared with the conventional 18 pulse rectifier system input current and output voltage. The main reasons for the unbalanced output voltage of the multi-pulse rectifier system are the voltage imbalance of the grid side and the structure of the rectifier transformer asymmetry. First of all. In this paper, the influence of the unsymmetrical number of turns in the winding of rectifier transformer on the unbalanced output voltage of the system is studied, and the expressions between them are calculated according to the triangle sine cosine theorem. The waveform diagram between them is drawn by simulation. Secondly, the quantitative relationship between the unbalanced three-phase input voltage and the output voltage unbalance of rectifier transformer is studied in this paper. Finally, the variation law of total harmonic distortion rate of grid-side current under various unbalanced conditions is studied and compared with the simulation results. Finally, an 18-pulse rectifier system platform is built. The specific steps of the main circuit device selection and the software flow chart of the control system are given, and the 18 pulse DC side harmonic suppression system is debugged, and the experimental verification is completed.
【學位授予單位】：中國礦業(yè)大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TM761

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相關期刊論文 前1條

1 馬宏偉;李永東;鄭澤東;許烈;;一種PWM整流器的模型預測控制方法[J];電力自動化設備;2013年11期

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本文編號：1464008