基于不对称控制的宽增益LLC谐振变换器

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文献标志码：A 文章编号：1007-449X（2025）11-0056-13

Wide-gain LLC resonance converter based on asymmetric control

ZHANG Baoge， MA Li， LI Shaoning， WANG Yuan （School of Automation and Electrical Engineering，Lanzhou Jiaotong University，Lanzhou 730070，China）

Abstract：Aiming at the problems of limited voltage gain regulation ability，large cycle current and significant decline in conversion effciency of traditional variable-frequency controlled LLC resonant converters in wide output voltage range applications，an asymmetrically controlled wide-gain LLC resonant converter was proposed.This converter is based on fixed-frequency asymmetric control and topological reconstruction of half-bridge and full-bridge combined switching. It could achieve four diferent gain operating modes at a fixed switching frequency，efectively expanding the voltage regulation range，reducing the influence of the resonant cavity inductance ratio on the gain，simplifying the system design，and simultaneously reducing the lossof cyclic current and improving the system eficiency of the converter. In addition， the converter could achieve zero-voltage turn-on of the primary switching tube and zero-current turn-off of the secondary rectifier diode across the entire voltage range，further reducing switching losses and reverse recovery losses. To verify the theoretical analysis，an experimental prototype with an input voltage of 311 V，an output voltage of 75V to 622V ，and a working frequency of 100kHz was designed and built. The experimental results confirm that the proposed converter has good gain regulation capability and high efficiency characteristics under a wide range of output conditions.

Keywords：LLC resonant converter; double transformer; fixed-frequency asymmetric control； soft switch technology ; multimodal transformation ; wide voltage gain

0引言

LLC谐振变换器具有软开关特性，能够在全电压输出范围下实现一次侧逆变开关管的零电压开通（zero-voltageswitching，ZVS）和二次侧整流管的零电流关断（zero current switch，ZCS），可实现在高功率密度以及高频条件下的低损耗能量传输，因此LLC谐振变换器广泛应用于新能源汽车、电源系统、光伏发电等领域]

由于单独元器件的电流应力耐受性有限，通常采用多路并联的拓扑结构，这样不仅可以增加电路对高电压的耐受能力，而且可以减小各路元器件的电流应力，增加使用寿命，减少开关损耗[2] C

文献[3]提出一种L-LLC谐振变换电路，通过对特定元器件增加零电平的控制策略，实现谐振变换器的全桥模态和半桥模式切换，有效地拓宽了变换器的电压输出范围。（剩余12612字）