适应宽电压输入的两级式DC/DC变换器

Two-stage DC/DC Converter with Wide Voltage Input

模块化电源要求DC/DC变换器能适应宽范围电压输入,而单级式拓扑往往不能满足要求,为此,研究了一种两级式变换拓扑。该拓扑的第1级为具有宽调节特性的双管Buck/Boost变换器,第2级为具有软开关特性的LLC谐振变换器。分析了两级式变换器的工作原理、设计要点和数字化实现方式,搭建了输出功率为200 W的两级式DC/DC变换器原理样机。实验结果表明,提出的两级式变换拓扑具有输入电压范围宽、整机效率高的特点。

DC/DC converters which have high conversion efficiency and can work with wide range input are required in the modular power supplies.However,single-stage power topology often fails to meet the above requirements.A two-stage conversion topology was explored.The first stage is a dual switch Buck/Boost circuit with wide regulation,and the second stage is an LLC resonant converter with soft-switching characteristics.Firstly,the working principle,design points and digital implementation of two-stage converter were analyzed.Then,a prototype of the two-stage DC/DC converter with an output power of 200 W was built.The experimental results reveal that the twostage DC/DC topology proposed can adapt to a wide input voltage range with high overall machine efficiency.