摘要
针对服务器前端电源等对稳态效率和暂态升压能力具有特殊需求的应用场合,在LLC谐振变换器的整流电路中引入辅助开关网络,得到了一种改进的LLC谐振变换器。在额定输入电压附近,辅助开关网络保持关闭,变换器采用脉冲频率调制(PFM)调节输出电压;而当输入电压跌落时,辅助开关网络采用脉宽调制(PWM)策略,工作状态和Boost变换器类似,使变换器获得了额外的升压调节能力。对改进的LLC变换器的工作过程、电压增益特性进行分析,并给出了参数设计的方法。励磁电感的设计只需考虑稳态工作点的性能需求,与电压增益范围无关,有效减小了传统LLC变换器变压器因励磁电感过小而额外引入的环流损耗。最后通过实验验证了所提方案的可行性和有效性。
For the special requirements of steady-state efficiency and transient boost capability,such as front-end power supplies,an improved half-bridge(HB)LLC resonant converter was obtained by adding an auxiliary switching network.In normal operation,the auxiliary switch keeps off and pulse frequency modulation(PFM)is employed to regulate the output voltage.After an ac dropout,the auxiliary switching network operates with pulse width modulation(PWM)to improve voltage gain.The only design consideration of magnetizing inductance is the performance of steady state,regardless of voltage conversion gain range,resulting in reduced circulating current due to small magnetizing inductance.The feasibility and effectiveness of the proposed converter are verified by experiment results.
作者
汤欣喜
邢岩
吴红飞
赵健
Tang Xinxi;Xing Yan;Wu Hongfei;Zhao Jian(Center for More-Electric-Aircraft Power System Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China)
出处
《电工技术学报》
EI
CSCD
北大核心
2020年第4期767-774,共8页
Transactions of China Electrotechnical Society
基金
光宝电力电子技术科研基金资助项目(PRC20170953)
关键词
LLC谐振变换器
宽电压范围
脉宽调制
有源整流
LLC resonant converter
wide voltage range
pulse width modulation(PWM)
active rectifier
