新颖软开关推挽LLC谐振变流器及其拓扑延拓

为了解决在线式不间断电源系统(UPS)中,采用备用电池供电的升压直流-直流(dc-dc)变流器所存在的输入输出增益比和效率不能兼顾的问题,提出一种新颖的高效高增益升压推挽式隔离型电感-电感-电容(LLC)软开关串联谐振变流器.该变流器中的所有功率半导体元件均能实现软开关.通过工作在升压(Boost)模式下获得的高输入输出增益可有效减少变压器匝比,提高转换效率.内部驱动电路因基于推挽电路的结构而得以简化,该变流器适用于UPS电源系统中备用电池的能量升压转换场合.描述该变流器的工作原理和电路特性后,给出其拓扑的各种变化及变形结构,并用一台容量为600V·A的双路输出样机验证了该变流器的有效性和实用性.

Novel soft-switching push-pull type LLC resonant converter and its topology investigation

To overcome the limitation that the battery sourcing step up dc dc converters can not possess the merits of hicgh efficiency and highdc gain both in the application of back up mode for online uninterrupted power supply (UPS) systems, a novel step up push pull type isolated inductor inductor capacitor (LLC) series resonant dc dc converter was proposed. This converter possessed the soft switching advantage for all power semiconductors. When operated under Boost mode, the proposed converter obtained a high dc gain, which reduced the transformers turn ratio to improve conversion efficiency. The inside low side gate driving circuit was also simplified because of inherit of the push pull topology. Therefore, the proposed converter is quite suitable for the step up conversion under battery souring mode in UPS systems. The detail operation principles,characteristics and topdogy variations of the conveter were presented. the validity and applicability were also verified by a 600 V·A dual outputs prototype．