【摘要】：大功率整流器在國民經(jīng)濟的各個領(lǐng)域有著廣泛的應(yīng)用。但是,整流器件的強非線性和時變性使大功率整流器成為交流電網(wǎng)的主要諧波源。多脈波整流技術(shù)是解決大功率整流器諧波污染問題的有效途徑。該技術(shù)可以有效抑制輸入電流中的低次諧波,但對高次諧波無能為力。為進一步增強多脈波整流器的諧波抑制能力,本文將多脈波整流技術(shù)與直流側(cè)諧波抑制技術(shù)結(jié)合,在常規(guī)自耦型12脈波整流電路的基礎(chǔ)上,研究了一種帶Boost變換器的并聯(lián)型12脈波整流器。為了在仿真軟件中模擬星形自耦變壓器,建立了星形自耦變壓器的全解耦模型。首先,通過分析星形自耦變壓器輸入、輸出電壓相量的關(guān)系,確定了星形自耦變壓器的繞組結(jié)構(gòu)及變比;應(yīng)用相分量法,分析了星形自耦變壓器耦合電路中支路電壓、支路電流、節(jié)點電壓、節(jié)點電流之間的關(guān)系,得到了節(jié)點導(dǎo)納矩陣,該矩陣包含星形自耦變壓器的繞組連接特性、阻抗參數(shù)等相關(guān)信息,進一步確定了星形自耦變壓器的全解耦模型。仿真與實驗結(jié)果表明,應(yīng)用該模型,可對使用星形自耦變壓器的12脈波整流器進行有效模擬。為在直流側(cè)抑制并聯(lián)型12脈波整流器的輸入電流諧波,研究了理想狀態(tài)下12脈波整流器的直流側(cè)諧波抑制機理,并分析了輸入電壓不對稱諧波抑制性能的影響。利用開關(guān)函數(shù),計算了整流器網(wǎng)側(cè)輸入電流、電感電流的數(shù)量關(guān)系,分析了輸入電流為正弦波時所需電感電流波形,并給出了可實現(xiàn)的電感電流波形。引入輸入電壓不對稱因數(shù),分析了不對稱因數(shù)對三相輸入電壓、自耦變壓器輸出電壓的影響,確定了輸入電壓不對稱因數(shù)與整流器輸入電流的關(guān)系。理論分析表明,當電感電流滿足一定要求時,使用Boost變換器可有效抑制輸入電流諧波;輸入電壓的輕微不對稱對整流器的諧波抑制能力影響較小。為使整流器具有較好的穩(wěn)態(tài)特性和動態(tài)特性,建立了帶Boost變換器的并聯(lián)型12脈波整流器在峰值電流控制模式下的精確模型,并應(yīng)用該模型給出了電壓補償網(wǎng)絡(luò)的設(shè)計方案�？紤]元件部分寄生參數(shù)的影響,建立了非理想Boost變換器的小信號模型;研究了整流器在峰值電流控制模式下穩(wěn)定運行條件,給出了電壓補償網(wǎng)絡(luò)的設(shè)計方法。對帶Boost變換器的并聯(lián)型12脈波整流器進行了設(shè)計,并研制了一臺功率為2.25k W的實驗樣機。仿真和實驗結(jié)果表明,該系統(tǒng)具有優(yōu)良的諧波抑制性能和較快的動態(tài)響應(yīng)速度,且實現(xiàn)成本較低。
[Abstract]:High-power rectifiers are widely used in various fields of national economy. However, the high power rectifier becomes the main harmonic source of AC power grid because of its strong nonlinearity and time variation. Multi-pulse rectifier is an effective way to solve the problem of harmonic pollution in high power rectifier. This technique can effectively suppress the low order harmonics in the input current, but it is powerless for the high order harmonics. In order to further enhance the harmonic suppression ability of the multi-pulse rectifier, this paper combines the multi-pulse rectifier technology with the DC side harmonic suppression technology, based on the conventional self-coupled 12-pulse rectifier circuit. A parallel 12 pulse rectifier with Boost converter is studied. In order to simulate star-shaped autotransformer in simulation software, a fully decoupling model of star-shaped autotransformer is established. Firstly, by analyzing the relationship between input and output voltage phasor of star-shaped autotransformer, the winding structure and variable ratio of star-shaped autotransformer are determined, and the branch voltage in the coupling circuit of star-shaped autotransformer is analyzed by using phase-component method. The relationship among branch current, node voltage and node current is obtained. The node admittance matrix includes the winding connection characteristics of star autotransformer, impedance parameters and other related information. Furthermore, the fully decoupling model of star autotransformer is determined. The simulation and experimental results show that the 12 pulse rectifier using star autotransformer can be effectively simulated by using this model. In order to suppress the input current harmonics of the parallel 12-pulse rectifier at the DC side, the harmonic suppression mechanism of the 12-pulse rectifier in ideal condition is studied, and the effect of the asymmetric input voltage on the harmonic suppression performance is analyzed. By using switching function, the relationship between input current and inductor current in rectifier is calculated. The waveform of inductance current when input current is sinusoidal wave is analyzed, and the realizable inductance current waveform is given. The influence of asymmetry factor on three-phase input voltage and output voltage of autotransformer is analyzed, and the relation between the asymmetry factor of input voltage and input current of rectifier is determined. Theoretical analysis shows that when the inductance current meets certain requirements, the input current harmonics can be effectively suppressed by using Boost converter, and the slight asymmetry of input voltage has little effect on the harmonic suppression ability of rectifier. In order to make the rectifier have better steady-state and dynamic characteristics, an accurate model of parallel 12-pulse rectifier with Boost converter in peak-current control mode is established, and the design scheme of voltage compensation network is given. Considering the influence of some parasitic parameters of components, the small signal model of non-ideal Boost converter is established, and the stable operation condition of rectifier in peak current control mode is studied, and the design method of voltage compensation network is given. A parallel 12-pulse rectifier with Boost converter is designed, and an experimental prototype with power of 2.25kW is developed. The simulation and experimental results show that the system has excellent harmonic suppression performance, fast dynamic response speed and low cost.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TM46
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本文編號：2149994