宽范围CLLLC双向同步整流数字控制方法  

Digital Control Method of Wide-Range CLLLC Bidirectional Synchronous Rectification

作　　者：廖嘉睿 杭丽君[1] 但志敏 何远彬 高锦凤 Liao Jiarui;Hang Lijun;Dan Zhimin;He Yuanbin;Gao Jinfeng(Regional Energy Internet Technology Zhejiang Engineering LaboratoryHangzhou Dianzi University,Hangzhou 310018 China;Contemporary Amperex Technology Co.Ltd,Ningde 352000 China)

机构地区：[1]杭州电子科技大学区域能源互联网技术浙江省工程实验室,杭州310018 [2]宁德时代新能源科技有限公司,宁德352000

出　　处：《电工技术学报》2022年第14期3632-3642,共11页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(51777049,51707051)。

摘　　要：为解决车载充电器(OBC)系统的双向CLLLC谐振变换器在宽范围工作条件下效率过低、开关管温度过高等问题,该文提出一种数字同步整流控制方法。该方法以CLLLC拓扑的脉冲频率调制(PFM)控制模式为基础,通过对不同工作频率模态的分析,总结推导同步开关管与主动管驱动时间的关系。在宽电压的调制频率范围内,分别通过分析计算和线性函数分段拟合的方法得到同步管驱动信号的延迟开通和提前关断时间。相较于其他同步整流控制,此方法利用纯数字控制实现,可应用于母线电压变化范围宽的大功率场合,且适用于双向变换器,避免了模拟控制芯片对母线电压变化敏感的缺点,控制方法简单且易于实现,成本更低,设计更简单。最后,搭建了仿真平台和实验样机对所提出的方法进行验证。仿真和实验的结果表明,该策略可以使系统效率最大提升3%左右,且能极大降低开关管温度。In order to solve the problems of low efficiency and high temperature of the switches under a wide range of working conditions of the bidirectional CLLLC resonant converter,this paper proposes a digital synchronous rectification controller for the rectifier on the secondary side of the high frequency transformer.Based on the pulse frequency modulation(PFM)mode of the CLLLC circuit,the operating mode of different frequencies is analyzed,and the relationship between the driving signal of the synchronous switch and the driving signal of the active device on the primary side of the transformer is obtained.In a wide modulation frequency range,the delayed turn-on time and lead turn-off time of the driving signal for the synchronous devices is obtained respectively by calculation and piecewise linear function fitting methods.Compared with other synchronous rectification control,this method is realized by pure digital control,which can be applied to high-power applications with a wide range of bus voltage variation.Furthermore,this method is suitable for bidirectional converters.and avoids the shortcoming that the analog control chip is sensitive to bus voltage changes.Meanwhile,the proposed control method is simple to implement,and the cost and complexity of circuit can be reduced.Finally,a simulation platform and an experimental prototype were built to verify the proposed method.The results show that this strategy can increase the efficiency of the CLLLC system by about 3%,and can greatly reduce the temperature of the synchronous switches.

关 键 词：车载充电器 双向 CLLLC 变换器 脉冲频率调制(PFM) 数字同步整流 多线 性拟合 

分 类 号：TM46[电气工程—电器]