非对称半桥LLC谐振变换器同步整流数字设计

主要针对非对称半桥LLC谐振型变换器同步整流技术的数字化控制进行设计。由于工程应用中要求原边电流进行软件保护,因此在不增加额外电流互感器且满足工程需求的情况下,提出基于原边谐振电流和输出电压控制副边同步整流管导通时间的控制策略,有利于效率的提升,并给出了详细的时域分析。最后搭建了基于FPGA的300 W实验样机,实验结果表明,样机整机效率达到了92.1%。

Digital Design for Synchronous Rectification Used in LLC Resonant Converter with Asymmetrical Half-bridges

This paper mainly aims at the design of digital control of synchronous rectification technology used in LLC resonant converter with asymmetrical half-bridges. Considering that the primary-side current needs to be protected by software in engineering applications, under the premise of not adding additional current transformers while satisfying the engineering requirement, a control strategy based on the primary-side resonant current and output voltage is proposed to control the conduction time of the secondary synchronous rectifiers, which can improve the efficiency. Moreover, a detailed analysis in time domain is given. Finally, a 300 W experimental prototype based on field-programmable gate array(FPGA) was built, and experimental results showed that the prototype''s overall efficiency achieved 92.1%.