基于UC3863的串并联LLC谐振变换器  

LLC converter with series-parallel connection based on chip UC3863

作　　者：金爱娟[1] 倪似松 尹鹏鸿[1] 张艺[1] 李少龙[1] 

机构地区：[1]上海理工大学光学信息与计算机学院,上海200093

出　　处：《电源技术》2014年第12期2312-2315,2369,共5页Chinese Journal of Power Sources

基　　金：上海市教育委员会科研创新项目(09YZ214)

摘　　要：基于可控频率芯片UC3863的串并联LLC谐振变换器,变压器原边串行连接,副边并行连接。根据串联谐振变换器的特征,开关管零电压开启(ZVS),整流二极管零电流关断(ZCS),功率半导体元件上的开关损耗小。在该变换器中,两个LLC变换器的一次绕组是以串联的方式连接的,从而两个变换器就有相同的原始电流,保证了两个变换器可以提供均衡的负载电流,并且降低了峰值电流。在输出端,两个变换器是并联连接的,它们可以分担负载电流,并减少副边整流二极管上的电流应力。通过在反馈回路中引入变频控制芯片UC3863,来控制PWM序列。对所提出变换器的工作原理,稳态分析以及设计依据做了详细讨论。以输出24 V/21 A变换器为例,验证提出的变换器的特性。A series-parallel LLC resonant converter based on controllable frequency chip UC3863 was proposed： series-connected in primary side and parallel-connected in secondary side. According to the features of the series resonance converter, the switch tube was opened under zero voltage （ZVS）, rectifier diode switches was closed in zero current（ZCS）. Therefore, the loss of the switch on the power semiconductor devices was small. In this converter, two LLC converters were connected in series in primary side, so the two transformer had the same original current, to ensure the two converter could provide a balanced load current, and the peak current was reduced. On the output side, the two converter was connected in parallel, the load current was shared, and current stress of the rectifier diode at the secondary side was reduced. And the PWM sequence was controlled through the introduced controllable frequency chip UC3863 in the feedback loop. The working principle, steady-state analysis and design basis of the proposed converter were discussed. Through experiments with 24 V/21 A output, the characteristics of the proposed converter were verified.

关 键 词：LLC谐振变换 ZVC ZCS UC3863 

分 类 号：TM131[电气工程—电工理论与新技术]