基于简化时域模型的LLC谐振变换器同步整流在线驱动策略  

Synchronous Rectifier on-Line Driving Strategy for LLC Resonant Converter Based on a Simplified Time Domain Model

作　　者：张宇鑫 陈捷 王简 佘焱[1] 王勇[1] Zhang Yuxin;Chen Jie;Wang Jian;She Yan;Wang Yong(Department of Electrical Engineering Shanghai Jiaotong University,Shanghai 200240 China)

机构地区：[1]上海交通大学电气工程系,上海200240

出　　处：《电工技术学报》2025年第8期2615-2629,共15页Transactions of China Electrotechnical Society

摘　　要：LLC谐振变换器因其高效率、高功率密度和宽范围电压输出的优点,常应用于电动汽车充电装置中。为了进一步提高效率,该变换器的二次侧采用同步整流技术。因传统的同步整流方案受到了一系列限制,包括电流互感器成本高、高压检测困难、工作范围窄、计算负担重或准确度不高等问题。为解决这些问题,提出一种无高频采样的LLC谐振变换器同步整流方案。该方案基于简化的时域分析,在线识别LLC谐振变换器的不同工作模式并实时计算同步整流管的导通或延迟导通占空比。仿真结果表明,所提方法可在全频率范围与各种负载工况下实现同步整流管的精确驱动,且与其他基于模型的无高频采样驱动方案相比,该方案更为精确。最后,通过构建一台6.6 kW的实验样机,验证了该方案的稳态精确性和动态可靠性。The LLC converter plays a pivotal role in the infrastructure supporting electric vehicles,where efficiency and reliability are paramount.Its ability to efficiently transfer energy between different voltage levels makes it particularly suitable for EV charging stations,where power conversion efficiency directly impacts operational costs and environmental sustainability.Synchronous rectification has emerged as a promising strategy for optimizing LLC converter performance.By replacing traditional diode rectifiers with active switches that operate synchronously with the converter's switching frequency,synchronous rectification minimizes energy losses and improves overall efficiency.However,existing synchronous rectification methods have faced challenges,such as complex control algorithms,sensitivity to load variations,and the need for high-frequency sampling.Unlike conventional approaches that rely on high-frequency sampling for precise timing control,the novel synchronous rectification scheme utilizes a streamlined time-domain analysis.This approach dynamically adjusts the timing of the synchronous rectifier based on real-time feedback from the LLC converter's operating modes,ensuring optimal efficiency across a wide range of operating conditions with high-frequency sampling and alleviating the computational burden.By reducing the complexity of control algorithms and eliminating the need for high-frequency sampling circuits,the scheme not only lowers manufacturing costs but also enhances reliability by reducing potential points of failure.This simplification is particularly advantageous in high-power applications like EV charging stations,where robustness and operational uptime are essential.Simulation studies have validated the effectiveness of the proposed scheme under different load conditions and frequencies.Simulations have shown significant efficiency improvements compared to traditional methods,highlighting the scheme's potential to reduce energy losses and improve overall system performance.Furthermore,exper

关 键 词：LLC谐振变换器 时域分析 同步整流 模式识别 

分 类 号：TM46[电气工程—电器]