基于SEPIC電路的單級(jí)LLC諧振變換器研究
發(fā)布時(shí)間：2019-03-19 17:21
【摘要】：LED作為新一代綠色光源,具有光效高、壽命長(zhǎng)、響應(yīng)快等優(yōu)點(diǎn),已經(jīng)廣泛應(yīng)用于路燈照明、汽車照明等領(lǐng)域。傳統(tǒng)的LED驅(qū)動(dòng)為兩級(jí)式結(jié)構(gòu),兩級(jí)結(jié)構(gòu)具有較高的PF和較低的THD值,但是存在器件多、體積大、控制較為復(fù)雜、成本較高等缺點(diǎn)。單級(jí)交直流變換器因其高可靠性、高功率密度而成為研究熱點(diǎn)。但是目前的單級(jí)結(jié)構(gòu)大多工作在硬開(kāi)關(guān)狀態(tài),系統(tǒng)開(kāi)關(guān)損耗較高,無(wú)法應(yīng)用在大功率LED驅(qū)動(dòng)系統(tǒng)中。本文在拓?fù)浼杉s束條件下,通過(guò)集成Sepic電路的開(kāi)關(guān)器件和LLC半橋諧振電路的開(kāi)關(guān)器件,提出一種新型單級(jí)交直流變換器結(jié)構(gòu)。由于集成了兩級(jí)的開(kāi)關(guān)器件,系統(tǒng)所用的器件較少,降低了系統(tǒng)成本并提高了系統(tǒng)可靠性。同時(shí)由于LLC諧振電路在系統(tǒng)集成后,仍具有軟開(kāi)關(guān)特性,系統(tǒng)開(kāi)關(guān)損耗較低,母線電壓較低,適合應(yīng)用在大功率LED驅(qū)動(dòng)系統(tǒng)中。本文首先根據(jù)SSC集成理論實(shí)現(xiàn)了兩級(jí)變換器到單級(jí)變換器的集成變換,對(duì)單級(jí)結(jié)構(gòu)進(jìn)行了模態(tài)分析,得出了單周期的典型波形。并以母線電壓為中間變量,對(duì)所提變換器的Sepic單元和LLC單元進(jìn)行了深入分析,給出了分析過(guò)程。其次對(duì)所提系統(tǒng)進(jìn)行了優(yōu)化設(shè)計(jì),包括前后單元典型器件的參數(shù)計(jì)算與設(shè)計(jì),對(duì)輔助電源、驅(qū)動(dòng)電路、采樣電路的設(shè)計(jì)等。接下來(lái)通過(guò)擴(kuò)展描述函數(shù)方法,建立了LLC諧振電路的數(shù)學(xué)模型,提出了優(yōu)化的補(bǔ)償方式,并根據(jù)雙線性變換法提出系統(tǒng)的數(shù)字化控制策略。最后,在理論研究與分析的基礎(chǔ)上,對(duì)系統(tǒng)進(jìn)行仿真,并繪制原理圖,搭建實(shí)驗(yàn)平臺(tái),進(jìn)行實(shí)驗(yàn)驗(yàn)證。實(shí)驗(yàn)結(jié)果表明,所提單級(jí)結(jié)構(gòu)能夠可靠實(shí)現(xiàn)功率因數(shù)校正功能,同時(shí)系統(tǒng)工作在軟開(kāi)關(guān)狀態(tài)下,穩(wěn)態(tài)時(shí)效率高達(dá)92%。
[Abstract]:As a new generation of green light source, LED has many advantages, such as high light efficiency, long life and fast response. It has been widely used in street lamp lighting, automobile lighting and other fields. The traditional LED driver is a two-stage structure. The two-stage structure has the disadvantages of high PF and low THD value, but there are many devices, large volume, complicated control and high cost. Single-stage AC-DC converter has become a research hotspot because of its high reliability and high power density. However, most of the current single-stage structures work in the hard-switching state, the switching loss of the system is high, and can not be used in the high-power LED drive system. In this paper, a novel single-stage AC-DC converter is proposed by integrating the switching device of Sepic circuit and the switch device of LLC half-bridge resonant circuit under the constraint of topology integration. As a result of the integration of two-stage switching devices, the system uses fewer devices, reducing the system cost and improving the reliability of the system. At the same time, the LLC resonant circuit still has the soft-switching characteristic after the system is integrated, the system switching loss is lower, the bus voltage is lower, so it is suitable for the high-power LED drive system. In this paper, the integration transformation from two-stage converter to single-stage converter is realized according to SSC integration theory. The modal analysis of single-stage converter is carried out, and the typical waveform of single-stage converter is obtained. Taking the bus voltage as the intermediate variable, the Sepic unit and the LLC unit of the proposed converter are deeply analyzed, and the analysis process is given. Secondly, the proposed system is optimized, including the calculation and design of the parameters of the typical devices in front and back units, the design of auxiliary power supply, driving circuit, sampling circuit and so on. Then, the mathematical model of LLC resonant circuit is established by extending the description function method, and the optimized compensation method is proposed, and the digital control strategy of the system is put forward according to bilinear transformation method. Finally, on the basis of theoretical research and analysis, the system is simulated, and the schematic diagram is drawn, the experimental platform is set up, and the experimental verification is carried out. The experimental results show that the proposed single-stage structure can achieve the power factor correction function reliably. At the same time, the system works in the soft-switching state, and the steady-state efficiency is as high as 92%.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TM46
本文編號(hào)：2443732
[Abstract]:As a new generation of green light source, LED has many advantages, such as high light efficiency, long life and fast response. It has been widely used in street lamp lighting, automobile lighting and other fields. The traditional LED driver is a two-stage structure. The two-stage structure has the disadvantages of high PF and low THD value, but there are many devices, large volume, complicated control and high cost. Single-stage AC-DC converter has become a research hotspot because of its high reliability and high power density. However, most of the current single-stage structures work in the hard-switching state, the switching loss of the system is high, and can not be used in the high-power LED drive system. In this paper, a novel single-stage AC-DC converter is proposed by integrating the switching device of Sepic circuit and the switch device of LLC half-bridge resonant circuit under the constraint of topology integration. As a result of the integration of two-stage switching devices, the system uses fewer devices, reducing the system cost and improving the reliability of the system. At the same time, the LLC resonant circuit still has the soft-switching characteristic after the system is integrated, the system switching loss is lower, the bus voltage is lower, so it is suitable for the high-power LED drive system. In this paper, the integration transformation from two-stage converter to single-stage converter is realized according to SSC integration theory. The modal analysis of single-stage converter is carried out, and the typical waveform of single-stage converter is obtained. Taking the bus voltage as the intermediate variable, the Sepic unit and the LLC unit of the proposed converter are deeply analyzed, and the analysis process is given. Secondly, the proposed system is optimized, including the calculation and design of the parameters of the typical devices in front and back units, the design of auxiliary power supply, driving circuit, sampling circuit and so on. Then, the mathematical model of LLC resonant circuit is established by extending the description function method, and the optimized compensation method is proposed, and the digital control strategy of the system is put forward according to bilinear transformation method. Finally, on the basis of theoretical research and analysis, the system is simulated, and the schematic diagram is drawn, the experimental platform is set up, and the experimental verification is carried out. The experimental results show that the proposed single-stage structure can achieve the power factor correction function reliably. At the same time, the system works in the soft-switching state, and the steady-state efficiency is as high as 92%.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TM46
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 王雪飛;范鵬;;串并聯(lián)諧振高壓變換器的分析與設(shè)計(jì)[J];電力電子技術(shù);2008年09期
，本文編號(hào)：2443732
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