一种应用于移相调制同步整流型谐振变换器的轻载效率优化分析方法  

A Light Load Efficiency Optimal Analysis Method Applied to Phase-Shift-Modulation Synchronous Rectification Resonant Converters

作　　者：陈梦颖 陈博 刘超 王议锋 王萍 Chen Mengying;Chen Bo;Liu Chao;Wang Yifeng;Wang Ping(School of Electrical and Information Engineering Tianjin University,Tianjin 300072 China;State Grid Jining Power Supply Company,Jining 272000 China)

机构地区：[1]天津大学电气自动化与信息工程学院,天津300072 [2]国网济宁供电公司,济宁272000

出　　处：《电工技术学报》2025年第6期1900-1914,共15页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金青年基金——建筑/户用兆赫兹千瓦级储能双向直流变换技术及其控制方法研究(52307216);基于宽禁带器件的高效率无隔离变低压柔性互联关键技术研究(5400-202418174A-1-1-ZN)资助项目。

摘　　要：针对移相调制轻载零电压软开关(ZVS)缺失效率低下的问题,该文提出一种应用于移相调制同步整流型谐振变换器的轻载效率优化分析方法。该方法采用同步整流管提前导通的方式,通过调节同步整流管的开通时序,实现了部分能量从二次侧到一次侧的回馈。在同步整流开关管提前导通的过程中,降低的损耗(一次侧滞后桥臂开关管开通损耗和输出电容损耗)和增加的损耗(一次侧滞后桥臂开关管关断损耗和回路导通损耗)之间形成动态博弈,这对变换器的综合效率具有重要影响。通过构建受控变量(同步整流开关管提前导通时间TR)与损耗(P_(loss))之间的数学模型,该文总结得出不同工作条件下损耗导数(P'_(loss))和T_R的基本关系。由此,变换器获得了优化的提前导通时间(T_(R_(op)))及相应的优化效率(η_(op))。为验证理论分析的有效性,基于LCLC谐振变换器,该文搭建一台500 W的实验样机。相比传统控制方法,采用该文效率优化分析方法后,轻载(20%负载)运行效率提升2%以上(93.757%~95.821%)。The characteristics of high efficiency and wide gain are the key indicators of the operational performance of resonant converters.Traditionally,pulse frequency modulation(PFM)is used to adjust the voltage gain of resonant converters.However,due to inherent structural limitations,the classical resonant converter has a flat voltage gain curve in the over-resonant region(fs>fr),which makes it difficult to adapt to wide output voltage applications,such as the LLC and LCLC resonant converters.Therefore,phase shift modulation(PSM)can be employed.It can effectively widen the voltage gain range.Unfortunately,the traditional PSM control method faces the problem of missing soft switching in the lagging bridge arm under light load conditions.Thus,this paper proposes a light load efficiency optimal analysis method for phase-shift-modulated synchronous rectification resonant converters(LLEOAM).Firstly,the idea that the synchronous rectifier is conducted in advance is adopted in the LLEOAM.By adjusting the advance conduction time of the synchronous rectifier,some energy is fed back from the secondary side to the primary side.Interestingly,in the process of increasing the advance conduction time of the synchronous rectifier,there is a dynamic game between the reduced loss(turning on loss and output capacitance loss of the primary lagging bridge arm switch)and the increased loss(turning off loss of the primary lagging bridge arm switch and loop conduction loss),which has an important impact on the overall efficiency.Secondly,by constructing the mathematical model between the controlled variable(the synchronous rectifier advance conduction time TR)and the loss(Ploss),the basic relationship diagram between the loss derivative(P′_(loss))and T_(R) under different working conditions is put forward and summarized.Finally,the optimized advance conduction time(TR_op)and the corresponding optimization efficiency(ηop)are obtained.Overall,LLEOAM adopts the idea of a loss game to propose a general and universal T_(R) calculation method i

关 键 词：移相调制 效率优化 多谐振直流变换器 同步整流 软开关 

分 类 号：TM46[电气工程—电器]