【摘要】：開(kāi)關(guān)電源在各類電子設(shè)備中以體積小、重量輕、轉(zhuǎn)換效率高等優(yōu)點(diǎn)成為研究熱點(diǎn)。小功率開(kāi)關(guān)電源的發(fā)展方向趨于高頻化與小型化,但是,由于部分電子元件的約束,功率密度很難進(jìn)一步提高。本文從四個(gè)途徑進(jìn)行隔離型高功率密度變換器的研究:(1)電路拓?fù)浣Y(jié)構(gòu)通過(guò)幾種常用隔離型開(kāi)關(guān)電源電路拓?fù)浣Y(jié)構(gòu)的對(duì)比分析,選擇反激變換器的拓?fù)浣Y(jié)構(gòu)。通過(guò)對(duì)其工作原理及工作模式的分析,確定電流斷續(xù)工作模式。根據(jù)開(kāi)關(guān)電源的性能指標(biāo),對(duì)主功率電路關(guān)鍵元器件進(jìn)行參數(shù)計(jì)算和選型。(2)提高開(kāi)關(guān)頻率高頻可以減小磁性元件的體積,將開(kāi)關(guān)管的工作頻率定為500kHz。選取2MHz峰值電流控制模式的LM5022控制芯片,并對(duì)芯片外圍電路的設(shè)計(jì)及控制模式作了詳細(xì)的介紹。反激變換器在高頻關(guān)斷時(shí),會(huì)產(chǎn)生很大的尖峰電壓,RCD吸收電路可保證開(kāi)關(guān)管安全可靠工作。(3)采用GaN開(kāi)關(guān)器件GaN材料具有導(dǎo)通電阻較小、柵極電荷少、反向恢復(fù)電荷少、封裝極小的特點(diǎn),在高速開(kāi)關(guān)和低導(dǎo)通電阻方面優(yōu)勢(shì)明顯,將其應(yīng)用于高功率密度領(lǐng)域。針對(duì)GaN晶體管驅(qū)動(dòng)電壓窄的特點(diǎn),選取GaN晶體管單管專用驅(qū)動(dòng)芯片LM5114,設(shè)計(jì)的獨(dú)立推挽輸出驅(qū)動(dòng)電路能可靠穩(wěn)定的驅(qū)動(dòng)GaN開(kāi)關(guān)管。(4)采用平面變壓器磁芯元件平面結(jié)構(gòu)具有較大的散熱面積,降低元件熱點(diǎn)與磁性元件表面的熱阻,提高了功率密度。平面變壓器的制作與設(shè)計(jì)難度大,本文總結(jié)了其設(shè)計(jì)步驟與制作方法,通過(guò)反激式高頻變壓器詳述了設(shè)計(jì)過(guò)程,設(shè)計(jì)了一款轉(zhuǎn)換效率為98.012%,尺寸大小為18×10×6mm3的平面變壓器。通過(guò)以上四種途徑,研制出一款輸入24V,輸出5V/5A,工作頻率為500kHz,尺寸為34mm×18mm×6mm,效率是70.7%,功率密度為6.8W/cm3的隔離型開(kāi)關(guān)電源樣機(jī)。實(shí)驗(yàn)結(jié)果及分析驗(yàn)證該樣機(jī)是一款體積小,質(zhì)量輕,電磁兼容性好的高功率密度開(kāi)關(guān)電源。
[Abstract]:Switching power supply (SMPs) has become a research hotspot in all kinds of electronic devices because of its small size, light weight and high conversion efficiency. The development trend of low power switching power supply tends to be high frequency and miniaturization, but it is difficult to improve the power density because of the restriction of some electronic components. This paper studies the isolated high power density converter in four ways: (1) the topology of the flyback converter is selected by comparing and analyzing the topology of several common isolated switching power supply circuits. Through the analysis of its working principle and working mode, the current intermittent working mode is determined. According to the performance index of switching power supply, the parameters of key components of main power circuit are calculated and selected. (2) the volume of magnetic element can be reduced by increasing the high frequency of switch frequency, and the working frequency of switch tube is set at 500 kHz. The LM5022 control chip with 2MHz peak current control mode is selected, and the design and control mode of the peripheral circuit of the chip are introduced in detail. When the flyback converter is turned off at high frequency, a large peak voltage and RCD absorption circuit can be produced to ensure the safe and reliable operation of the switch. (3) the gan material with gan switch device has lower on-resistance, less gate charge and less reverse recovery charge. It has the advantages of high speed switch and low on-resistance, so it is used in high power density field. Aiming at the narrow driving voltage of gan transistor, The single transistor driver LM5114is selected, and the independent push-pull output drive circuit is designed to drive the gan switch reliably and stably. (4) the planar structure of the planar transformer core element has a large heat dissipation area. The thermal resistance of the hot spot and magnetic element surface is reduced, and the power density is increased. It is very difficult to make and design plane transformer. This paper summarizes the design steps and methods, describes the design process of flyback high frequency transformer, and designs a plane transformer with conversion efficiency of 98.012 and size of 18 脳 10 脳 6mm3. Through the above four ways, a prototype of an isolated switching power supply with input 24V, output 5V / 5A, working frequency 500kHz, dimension 34mm 脳 18mm 脳 6mm, efficiency 70.7 and power density 6.8W / cm3 has been developed. The experimental results and analysis show that the prototype is a high power density switching power supply with small volume, light weight and good electromagnetic compatibility.
【學(xué)位授予單位】：湖北工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TM46

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 譚琳琳;王康平;宇文甸;楊旭;;基于GaN器件LLC諧振變換器的平面變壓器優(yōu)化設(shè)計(jì)[J];電源學(xué)報(bào);2016年04期

2 鄒學(xué)文;董舟;周Z，

本文編號(hào)：2128671