LLC半桥式谐振变换器参数模型与设计

摘要

According to working principle of LLC topology,a mathematical model for LLC resonant half-bridge converter is presented in this paper.On the basis of conversion relations between the best conversion efficiency and wide scope of load changes,leakage inductance,magnetic inductance and resonant capacitance are confirmed according to the proposed model.Also a LLC resonant half-bridge converter is designed.By improving switch frequency to MHz-level,its converter efficiency can reach to 94% either in full or light loader.At the same time,the power density can reach to 500W/in3.Experiment results ultimately verify the correctness of the model and parameter deduction.%根据LLC拓扑结构工作原理,建立了LLC半桥式谐振变换器的数学模型。基于最优转换效率和宽负载变化范围的转换关系,根据模型确定了漏感、励磁电感和谐振电容,并设计了一款LLC半桥式谐振变换器,开关频率提高到兆赫兹级,在轻载和满载时效率均达到94%,功率密度达到500W/in3,实验结果表明了模型和参数设计的正确性。