实验技术与管理2025，Vol.42Issue(12)：85-92,8.DOI:10.16791/j.cnki.sjg.2025.12.010
基于相频补偿控制的宽增益C-LLC谐振变换器设计
Design of a wide-gain C-LLC resonant converter based on phase-frequency compensation control
摘要
Abstract
[Objective]LLC resonant converters have been widely adopted in medium-to high-power DC/DC applications because of their excellent soft-switching characteristics and electromagnetic compatibility.With the growing emphasis on carbon neutrality("dual carbon"goals),emerging applications such as electric vehicles,photovoltaic energy storage systems,and high-efficiency servers are placing increasing demands on power conversion systems.These systems require high power density and efficiency as well as stable operation across a wide range of input voltages.However,traditional LLC converters typically achieve wide gain regulation through extensive frequency modulation,which often leads to reduced efficiency,increased device stress,and greater control complexity.Moreover,during mode transitions,conventional LLC designs are prone to voltage overshoot in the resonant tank and system instability,limiting their applicability in high-performance scenarios.To address these challenges,this study proposes a wide-gain C-LLC resonant converter integrated with a phase-frequency compensation control strategy.[Methods]The proposed topology introduces an additional capacitor in parallel with the resonant inductor of a conventional LLC resonant tank.This capacitor is controlled by an auxiliary switch,enabling seamless switching between LLC and LCLC modes without significant structural complexity,thereby extending the system's voltage-gain range.To ensure smooth mode transitions,a phase-frequency compensation control strategy is developed based on gain matching and continuous frequency evolution.A mode selector determines the appropriate switching instant,while a PI controller and a voltage-controlled oscillator collaboratively generate the drive signals for both the main and auxiliary switches.From the theoretical perspective,the voltage gain characteristics under LLC frequency modulation,phase-shift control,and LCLC mode are individually derived.A unified equivalent circuit model is established using the fundamental harmonic approximation,and a composite gain curve is constructed to determine the optimal switching point.[Results]The proposed method was validated by designing and testing a 100 W experimental prototype.Across an input voltage range of 20‒96 V,the converter maintains zero-voltage switching on the primary-side MOSFETs and zero-current switching on the secondary-side diodes.During the mode transition,the proposed compensation strategy significantly reduces voltage overshoot in the resonant tank—from 136 V under direct switching to 71 V—achieving a 48%improvement.Additionally,the settling time is reduced from 0.68 s to 0.4 s,marking a 41%enhancement in the dynamic response.The constructed composite gain curve verifies the existence of an optimal gain-efficiency matched switching point,thereby improving the control stability and system robustness throughout the full operating range.[Conclusions]The proposed C-LLC resonant converter effectively balances wide-range gain regulation and soft-switching performance through a topology-enhancing design and a hybrid phase-frequency compensation control strategy.This approach enables efficient and smooth mode transitions,suppresses voltage overshoot,and accelerates the recovery of the system during transients.The results provide both theoretical insight and practical reference for the development of high-efficiency,wide-input-range power systems,offering promising potential in applications such as electric mobility,photovoltaic energy storage,and industrial-grade power supply.关键词
谐振变换器/相频补偿控制/宽增益/模式切换/超调Key words
text resonant converter/phase frequency compensation control/wide gain/mode switching/overshoot分类
信息技术与安全科学引用本文复制引用
FENG Xingtian,FAN Yanqi..基于相频补偿控制的宽增益C-LLC谐振变换器设计[J].实验技术与管理,2025,42(12):85-92,8.基金项目
山东省高等教育本科教学改革研究项目(M2023147) （M2023147）
山东省研究生优质专业学位教学案例库项目(SDYAL2023028) （SDYAL2023028）
中国石油大学(华东)教改项目(CM2024022) （华东）
