一种带辅助双向开关单元的宽输入电压范围LLC谐振变换器  

An Improved LLC Resonant Converter with Auxiliary Bi-Directional Switch for Wide-Input-Voltage Range Applications

作　　者：杨东江 段彬[1] 丁文龙 宋金秋 张承慧[1] Yang Dongjiang;Duan Bin;Ding Wenlong;Song Jinqiu;Zhang Chenghui(School of Control Science and Engineering Shandong University,Jinan 250061,China)

机构地区：[1]山东大学控制科学与工程学院

出　　处：《电工技术学报》2020年第4期775-785,共11页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金项目(61527809,U1764258,61703239);山东省重点研发计划(2016ZDJS03A02)资助

摘　　要：以软开关特性及高效而著称的LLC谐振变换器,往往需要具备宽输入电压范围,以满足掉电保持时间的实际应用要求。常采用降低励磁电感值的方法,但会增大谐振网络回流功率,降低运行效率。为此,提出一种带辅助双向开关单元的LLC谐振变换器,能够在输入母线电压跌落时,充分利用辅助双向开关单元,使得变换器能够在较大的励磁电感下,实现高电压增益和高效常态运行。该文详细描述分析了变换器在常态和掉电保持两种模式下的运行过程、电压增益特性及谐振元件设计约束条件,为变换器的设计提供了理论基础。进而,搭建了工作电压200~390V,输出48V/21A的样机。实验结果表明,该文所提出的变换器兼具常态运行时高效率和掉电保持运行时宽输入电压范围的优点,应用价值高。Wide input voltage range is a critical feature for LLC converter to guarantee enough hold-up time. A small magnetizing inductor can bring wide input voltage range for conventional LLC converter for hold-up operation. However, this inevitably increases reactive power and reduces efficiency for normal operation. In this paper, an improved LLC converter with auxiliary bidirectional switch is proposed to obtain enough voltage gain in hold-up mode with larger magnetizing inductor to reduce normal losses. The working principle, voltage gain and design rules in normal operation mode and hold-up mode are analyzed in detail. Finally, a prototype with 200~390 V input voltage range and 48 V/21 A output is built and tested, which demonstrates the proposed converter has high efficiency and wide input voltage range.

关 键 词：LLC谐振变换器 辅助双向开关 掉电保持模式 宽输入电压范围 

分 类 号：TM46[电气工程—电器]