Abstract：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, experimental validation using a 6.6 kW prototype shows that the proposed scheme delivers consistent and efficient operation under steady-state and dynamic conditions, further supporting its potential for commercial EV charging infrastructure integration. The adoption of the proposed synchronous rectification scheme promises to enhance the efficiency and reliability of LLC converters and accelerate the transition to electric mobility. As governments and industries worldwide prioritize sustainability goals and seek to reduce carbon footprints, improvements in energy conversion technologies play a crucial role in supporting the widespread adoption of electric vehicles. In conclusion, the synchronous rectification scheme represents a significant step in evolving LLC converters for electric vehicle charging infrastructure. By overcoming traditional limitations and leveraging streamlined control strategies, the scheme enhances performance and contributes to the sustainability of transportation systems. As research continues to refine and optimize power conversion technologies, the ongoing advancements in LLC converter designs underscore their pivotal role in shaping a cleaner, greener future for global transportation.
张宇鑫, 陈捷, 王简, 佘焱, 王勇. 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[J]. 电工技术学报, 2025, 40(8): 2615-2629.
Zhang Yuxin, Chen Jie, Wang Jian, She Yan, Wang Yong. Synchronous Rectifier on-Line Driving Strategy for LLC Resonant Converter Based on a Simplified Time Domain Model. Transactions of China Electrotechnical Society, 2025, 40(8): 2615-2629.
[1] Li Haoran, Zhang Zhiliang, Wang Shengdong, et al.A 300-kHz 6.6-kW SiC bidirectional LLC onboard charger[J]. IEEE Transactions on Industrial Elec-tronics, 2020, 67(2): 1435-1445. [2] 李彬彬, 王志远, 张丙旭, 等. 采用辅助变压器的可调压谐振零电压零电流开关变换器[J]. 电力系统自动化, 2022, 46(7): 160-169. Li Binbin, Wang Zhiyuan, Zhang Bingxu, et al.Voltage-regulatable resonant zero-voltage zero-current switching converter with auxiliary trans-former[J]. Automation of Electric Power Systems, 2022, 46(7): 160-169. [3] 桑汐坤, 王懿杰, 徐殿国. 基于输入并联输出串联的高效高升压比DC-DC变换器[J]. 电工技术学报, 2023, 38(20): 5488-5502. Sang Xikun, Wang Yijie, Xu Dianguo.High-efficiency high voltage gain DC-DC converter based on input parallel and output series connection[J]. Transactions of China Electrotechnical Society, 2023, 38(20): 5488-5502. [4] 陈梦颖, 陈博, 刘超, 等. 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[J]. 电工技术学报, 2025, 40(6): 1900-1914. Chen Mengying, Chen Bo, Liu Chao, et al.A light load efficiency optimal analysis method applied to phase-shift-modulated synchronous rectification[J]. Transactions of China Electrotechnical Society, 2025, 40(6): 1900-1914. [5] 何晓坤, 胡仁杰, 陈武. 一种适用于新能源中压直流汇集的无环流零电流软开关三电平谐振式复合全桥变换器[J]. 电工技术学报, 2023, 38(19): 5274-5287. He Xiaokun, Hu Renjie, Chen Wu.A novel circulating current free zero current switching three-level resonant composite full bridge converter for new energy medium voltage DC collection system[J]. Transactions of China Electrotechnical Society, 2023, 38(19): 5274-5287 [6] 鲁静, 同向前, 尹军, 等. L-LLC谐振型双向DC-DC变换器轻载优化控制策略研究[J]. 电工技术学报, 2022, 37(17): 4458-4465. Lu Jing, Tong Qianqian, Yin Jun, et al.The optimal control strategy for L-LLC bi-directional resonant DC-DC converter under light load[J]. Transactions of China Electrotechnical Society, 2022, 37(17): 4458-4465. [7] Wei Yuqi, Luo Quanming, Mantooth H A.Syn-chronous rectification for LLC resonant converter: an overview[J]. IEEE Transactions on Power Electronics, 2021, 36(6): 7264-7280. [8] Yu Haiming, Xie Xiaogao, Xu Sen, et al.A novel synchronous rectifier driving scheme for LLC converter based on secondary rectification current emulation[J]. IEEE Transactions on Power Elec-tronics, 2022, 37(4): 3825-3835. [9] 吕征宇, 李佳晨, 杨华. 新型LLC谐振变换器数字同步整流驱动方式[J]. 电机与控制学报, 2018, 22(1): 16-22. Lü Zhengyu, Li Jiachen, Yang Hua.Digital syn-chronous rectification driving method for LLC resonant converter[J]. Electric Machines and Control, 2018, 22(1): 16-22. [10] 孙城皓, 孙秋野, 王睿, 等. 基于拓展型双曲正切函数的全桥LLC变换器大信号建模方法[J]. 电工技术学报, 2023, 38(1): 234-245. Sun Chenghao, Sun Qiuye, Wang Rui, et al.Large-signal modeling method of full-bridge LLC converter based on extended hyperbolic tangent function[J]. Transactions of China Electrotechnical Society, 2023, 38(1): 234-245. [11] Wu Xinke, Hua Guichao, Zhang Junming, et al.A new current-driven synchronous rectifier for series-parallel resonant (LLC) DC-DC converter[J]. IEEE Transactions on Industrial Electronics, 2011, 58(1): 289-297. [12] Xu Shengyou, Qian Qinsong, Tao Tao, et al.Syn-chronous rectification using resonant capacitor voltage for secondary side resonant active clamp flyback converter[C]//2020 IEEE Applied Power Electronics Conference and Exposition (APEC), New Orleans, LA, USA, 2020: 2926-2931. [13] Hsu J D, Ordonez M, Eberle W, et al.LLC syn-chronous rectification using resonant capacitor voltage[J]. IEEE Transactions on Power Electronics, 2019, 34(11): 10970-10987. [14] Mohammadi M, Ordonez M.Synchronous recti-fication of LLC resonant converters using homopolarity cycle modulation[J]. IEEE Transactions on Industrial Electronics, 2019, 66(3): 1781-1790. [15] 王广旭. 具有寄生电感补偿的LLC同步整流电路设计[D]. 南京: 东南大学, 2021. Wang Guangxu.Design of LLC synchronous rectifier circuit with parasitic inductance compensation[D]. Nanjing: Southeast University, 2021. [16] Feng Weiyi, Lee F C, Mattavelli P, et al.A universal adaptive driving scheme for synchronous rectification in LLC resonant converters[J]. IEEE Transactions on Power Electronics, 2012, 27(8): 3775-3781. [17] Ivensky G, Bronshtein S, Abramovitz A.Approximate analysis of resonant LLC DC-DC converter[J]. IEEE Transactions on Power Electronics, 2011, 26(11): 3274-3284. [18] Fang Xiang, Hu Haibing, Shen Z J, et al.Operation mode analysis and peak gain approximation of the LLC resonant converter[J]. IEEE Transactions on Power Electronics, 2012, 27(4): 1985-1995. [19] 王志刚, 董长城, 侯凯, 等. 全桥LLC电路时域模型及其分析[J]. 电力系统自动化, 2018, 42(20): 138-143, 164. Wang Zhigang, Dong Changcheng, Hou Kai, et al.Time domain model of full bridge LLC circuit and its analysis[J]. Automation of Electric Power Systems, 2018, 42(20): 138-143, 164. [20] 李浩然, 崔超辉, 王生东, 等. 基于二阶拟合模型的SiC双向LLC数字同步整流控制[J]. 电工技术学报, 2022, 37(24): 6191-6203. Li Haoran, Cui Chaohui, Wang Shengdong, et al.Two-order fitting model-based digital synchronous rectifier control for SiC bidirectional LLC con-verter[J]. Transactions of China Electrotechnical Society, 2022, 37(24): 6191-6203. [21] Li Haoran, Wang Shengdong, Zhang Zhiliang, et al.A bidirectional synchronous/asynchronous rectifier control for wide battery voltage range in SiC bidi-rectional LLC chargers[J]. IEEE Transactions on Power Electronics, 2022, 37(5): 6090-6101. [22] Zhu Xinyi, Li Haoran, Zhang Zhiliang, et al.A sensorless model-based digital driving scheme for synchronous rectification in 1-kV input 1-MHz GaN LLC converters[J]. IEEE Transactions on Power Electronics, 2021, 36(7): 8359-8369. [23] 汪洪亮, 高文勇, 唐伟, 等. 基于时域分析的LLC同步整流控制研究[J]. 电力电子技术, 2023, 57(8): 104-107. Wang Hongliang, Gao Wenyong, Tang Wei, et al.Research on LLC synchronous rectification control based on time domain analysis[J]. Power Electronics,2023, 57(8): 104-107. [24] Pei Long, Jia Lixin, Wang Laili, et al.A novel dual-feedforward strategy for both the inverter-control and rectifier-control of LLC converters based on time-domain model[C]//2023 IEEE 14th Inter-national Symposium on Power Electronics for Distributed Generation Systems (PEDG), Shanghai, China, 2023: 1103-1108. [25] Li Haoran, Wang Shengdong, Zhang Zhiliang, et al.Bidirectional synchronous rectification on-line calcu-lation control for high voltage applications in SiC bidirectional LLC portable chargers[J]. IEEE Transa-ctions on Power Electronics, 2021, 36(5): 5557-5568. [26] 张朝阳. 基于多变量的全桥LLC谐振变换器混合控制策略研究[D]. 哈尔滨: 哈尔滨工业大学, 2020. Zhang Chaoyang.Research on hybrid control strategy of full-bridge LLC resonant converter based on multivariable[D]. Harbin: Harbin Institute of Tech-nology, 2020. [27] 陈孝莺, 许国, 韩华, 等. 基于脉宽调制的电流断续型谐振变换器[J]. 电工技术学报, 2022, 37(24): 6252-6261. Chen Xiaoying, Xu Guo, Han Hua, et al.Dis-continuous current mode resonant converter with pulse width modulation control[J]. Transactions of China Electrotechnical Society, 2022, 37(24): 6252-6261. [28] Chen Jie, Xu Junzhong, Tang Haiguo, et al.Second harmonic voltage suppression for LLC converter in dual-stage single-phase rectifier based on voltage-oriented state plane feedforward control[J]. IEEE Transactions on Power Electronics, 2023, 38(8): 9329-9334. [29] 程鹤, 徐恺, 李朋圣, 等. 三相CLLC谐振变换器磁集成平面变压器设计与优化[J]. 电工技术学报, 2024, 39(12): 3774-3786. Cheng He, Xu Kai, Li Pengsheng, et al.Design and optimization of three-phase CLLC resonant converter with magnetic integrated planar transformer[J]. Transactions of China Electrotechnical Society, 2024, 39(12): 3774-3786.
2025, Vol. 40 
