基于PFM控制的高效GaN全桥LLC谐振变换器设计  

Design of high⁃efficiency GaN full⁃bridge LLC resonant converter based on PFM control

作　　者：高圣伟[1] 贺琛 GAO Shengwei;HE Chen(Tianjin Key Laboratory of Advanced Technology of Electrical Engineering and Energy,Postdoctoral Research Station of School of Mechanical Engineering,Tianjin Polytechnic University,Tianjin 300387,China)

机构地区：[1]天津工业大学电工电能新技术天津市重点实验室机械工程学院博士后流动站,天津300387

出　　处：《现代电子技术》2021年第2期27-32,共6页Modern Electronics Technique

基　　金：国家自然科学基金重点资助项目(51337001);国家自然科学基金(51777136);天津市研究生科研创新项目(2019YJSS026)。

摘　　要：GaN MOSFET作为宽禁带的第三代半导体不仅开关速度快而且导通电阻小,把其用于变换器具有一定的高效性,而LLC谐振变换器作为高效的DC-DC变换器一直被广泛关注。现将GaN MOSFET用作全桥LLC谐振变换器的原边开关管进一步提升变换器的效率,并且通过PFM(变频)控制将变换器的工作频率划分为3个区域,进而找到效率最高的频率点,使变换器以此频率高效运行,文中对全桥LLC谐振变换器进行了参数设计,并基于Plecs和Matlab软件联合仿真验证参数和方案的可行性,搭建硬件平台得到谐振电流、输出电压的实验波形与仿真波形进行对比。实验结果表明,将GaN器件引入全桥LLC谐振变换器后能提高系统的频率及功率密度且最高效率可达96%。GaN MOSFET,as the third generation semiconductor with wide bandgap,not only has fast switching speed but also has low on⁃resistance,which has a certain high efficiency by applying it in to the converter.The LLC resonant converter taken as an efficient DC⁃DC converter has been widely concerned.The GaN MOSFET is used as the primary side switch tube of full⁃bridge LLC resonant converter to further improve the efficiency of the converter,the operating frequency of the converter is divided into three regions by means of the PFM frequency conversion control mode,and then the frequency point with the highest efficiency is found to make the converter run efficiently at this frequency.The parameters of the full bridge LLC resonant converter are designed.The feasibility of the parameters and the scheme are verified by co⁃simulation based on PLECS and Matlab softwares,and the hardware platform is built to obtain the experimental waveforms of resonant current and output voltage,which are compared with the simulation waveforms.The experimental results show that the frequency and power density of the system can be improved by introducing GaN devices into the full⁃bridge LLC resonant converter,and the maximum efficiency can reach 96%.

关 键 词：全桥LLC谐振变换器 PFM控制 参数设计 频率划分 方案验证 波形对比 

分 类 号：TN624-34[电子电信—电路与系统] TM46[电气工程—电器]