基于谐振开关电容技术的自动均压LLC谐振变流器

发布时间：2018-02-04 02:50

本文关键词： LLC谐振变流器自主均压高输入电压　出处：《浙江大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来,高电压高效率DC/DC变流器广泛应用于直流微网系统、现代通信电源、机车牵引和高压直流输电等领域。然而,由于材料特性和制造工艺等限制,现有的IGBT等功率器件难以实现高承受电压、高开关频率和低导通损耗的有机统一,严重影响了高输入电压变流场合的电气性能。如何从电路拓扑的角度实现创新,满足高输入电压、高开关频率、高功率密度和高变流可靠性的工业应用需求,是电力电子直流变换领域所面临的热点研究课题之一。本文提出一种基于谐振开关电容技术的自动均压LLC谐振变流器。变流器利用飞跨电容实现对输入电压的分压处理,把原边开关管的电压应力自动钳位在输入电压的一半,有利于变流器工作在高输入电压大功率的场合。输入电源经过飞跨电容的分压分流后连接到LLC谐振网络,利用LLC谐振变流器所具有的滞后功率因素特性实现原边开关管的软开关,减小开关损耗,提升变流器效率,并且利于实现高频化。此外,通过LLC谐振变流器所具有的频率增益特性,可以在较宽的范围内实现对变流器电压增益的调整。此外,本文提出的基于谐振开关电容技术的自动均压LLC谐振变流器所需的控制信号较为简单。最后,本文提出的电路可以推导至多级级联,从而应用于更高输入电压、更大降压比的应用场合。本文介绍该变流器的工作原理和电路特性,制作了一个500V-640V输入48V输出的1kW实验样机,并且验证了所提出的拓扑的有效性。
[Abstract]:In recent years, high voltage and high efficiency DC/DC converters have been widely used in the fields of DC microgrid system, modern communication power supply, locomotive traction and HVDC transmission. However, due to the material characteristics and manufacturing process, etc. The existing IGBT and other power devices are difficult to achieve high voltage, high switching frequency and low on-loss organic unity. It seriously affects the electrical performance of high input voltage converter. How to achieve innovation from the perspective of circuit topology to meet the high input voltage, high switching frequency, high power density and high reliability of industrial applications. It is one of the hot research topics in the field of power electronic DC conversion. This paper presents an automatic equalizing voltage LLC resonant converter based on resonant switched capacitor technology. The converter uses flyover capacitance to realize the input voltage. The partial pressure treatment. The voltage stress of the original side switch tube is automatically clamped at half of the input voltage. The input power supply is connected to the LLC resonant network after the split voltage and shunt of the flying capacitor. The LLC resonant converter has the characteristic of hysteresis power factor to realize the soft switch of the original side switch, reduce the switching loss, improve the efficiency of the converter, and facilitate the realization of high frequency. Through the frequency gain characteristic of LLC resonant converter, the voltage gain of converter can be adjusted in a wide range. The control signal of LLC resonant converter based on resonant switched capacitor technology is simple. Finally, the circuit can be deduced to multistage cascade. So it can be applied to the application of higher input voltage and higher voltage ratio. The working principle and circuit characteristics of the converter are introduced in this paper. A 1kW experimental prototype with 500V-640V input 48V output is made, and the validity of the proposed topology is verified.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM46

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