面向光伏并網(wǎng)逆變器的混合PWM調(diào)制方法
發(fā)布時(shí)間:2018-07-11 12:32
本文選題:光伏并網(wǎng)逆變器 + 特定諧波消除; 參考:《浙江大學(xué)》2014年碩士論文
【摘要】:PWM調(diào)制方式是并網(wǎng)逆變器中的關(guān)鍵技術(shù)之一。相比于正弦波PWM調(diào)制(SPWM)和空間矢量調(diào)制(SVPWM)方法,特定諧波消除法(SHEPWM)具有等效開(kāi)關(guān)頻率低、輸出電壓質(zhì)量好及損耗小等一系列優(yōu)點(diǎn)。 本文探討了T型三電平光伏并網(wǎng)逆變器采用特定諧波消除法(SHEPWM)的適應(yīng)性問(wèn)題。首先介紹了特定消除法的原理及實(shí)現(xiàn),比較了特定諧波消除法(SHEPWM)與空間矢量調(diào)制(SVPWM)兩種PWM調(diào)制方式對(duì)逆變器電能質(zhì)量、變換效率等影響。 本文還分析了影響特定諧波消除法性能的幾個(gè)因素,包括死區(qū)、母線電壓紋波和電網(wǎng)諧波的影響。由于這些因素的存在,使得SHEPWM的輸出電能質(zhì)量下降,一定程度的降低了光伏并網(wǎng)逆變器的并網(wǎng)電能質(zhì)量和整機(jī)效率。為克服這些因素,探討了改進(jìn)措施。 針對(duì)SHEPWM動(dòng)態(tài)性能差,不利于直接應(yīng)用到低電壓穿越等需要快速響應(yīng)的場(chǎng)合的問(wèn)題,本文提出了一種基于SHEPWM和SVPWM的混合調(diào)制方式,從而使得光伏并網(wǎng)逆變器具有很好的穩(wěn)態(tài)和動(dòng)態(tài)性能。此外,分析了影響兩種調(diào)制方式的平滑快速切換的因素。 在一臺(tái)10kWT型三電平光伏并網(wǎng)逆變器實(shí)驗(yàn)平臺(tái)上進(jìn)行了相關(guān)的實(shí)驗(yàn)。
[Abstract]:PWM modulation is one of the key technologies in grid-connected inverter. Compared with sine wave PWM (SPWM) and space vector modulation (SVPWM), special harmonic elimination (SHEPWM) has a series of advantages, such as low equivalent switching frequency, good output voltage quality and low loss. In this paper, the adaptability of T type three-level photovoltaic grid-connected inverter using special harmonic elimination (ShePWM) is discussed. Firstly, the principle and implementation of the special elimination method are introduced, and the effects of special harmonic elimination (ShePWM) and space vector modulation (SVPWM) on the power quality and conversion efficiency of the inverter are compared. Several factors affecting the performance of specific harmonic elimination methods are also analyzed, including dead-time, bus voltage ripple and power grid harmonics. Because of these factors, the output power quality of SHEPWM is decreased, and the power quality and efficiency of PV grid-connected inverter are reduced to a certain extent. In order to overcome these factors, the improvement measures are discussed. Aiming at the problem that the dynamic performance of ShePWM is poor and it is unfavorable to be directly applied to low-voltage traversing and other situations requiring rapid response, a hybrid modulation method based on ShePWM and SVPWM is proposed in this paper. Therefore, the photovoltaic grid-connected inverter has good steady-state and dynamic performance. In addition, the factors that affect the smooth and fast switching of the two modulation modes are analyzed. Experiments were carried out on a 10 kWT three-level photovoltaic grid-connected inverter.
【學(xué)位授予單位】:浙江大學(xué)
【學(xué)位級(jí)別】:碩士
【學(xué)位授予年份】:2014
【分類(lèi)號(hào)】:TM464
【參考文獻(xiàn)】
相關(guān)期刊論文 前2條
1 桂紅云;姚文熙;呂征宇;;中點(diǎn)箝位型三電平變換器SFOPWM方法的研究[J];電源技術(shù)應(yīng)用;2004年07期
2 劉文華,宋強(qiáng),陳遠(yuǎn)華,謝小榮;NPC逆變器SHE-PWM開(kāi)關(guān)角度的計(jì)算方法研究[J];中國(guó)電機(jī)工程學(xué)報(bào);2002年11期
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