中文摘要：

提出一种复合双频Buck变换器，对其工作原理和性能特点进行了详细分析。复合双频Buck变换器的高频部分为三电平Buck单元，低频部分为两电平Buck单元。与三电平Buck变换器相比，复合双频Buck变换器具有较高的效率，而且其“隔直”电容可以取得更小。与双频Buck变换器相比，其具有高频开关电压应力低，输出滤波电感、滤波电容小，动态负载性能好等优点。最后，在理论分析的基础上进行了实验研究。

英文摘要：

A kind of hybrid double frequency Buck converter is proposed in this paper, operation principle and property of this new converter are analyzed in detail. The high frequency part of hybrid double frequency Buck converter is a three level （TL） Buck cell, and the low frequency part is a two level Buck cell. When compared with TL Buck converter, efficiency of this new converter is higher and the DC voltage blocking capacitor can be smaller, when compared with double frequency Buck converter, voltage stress of the high frequency switches is lower, the output capacitor and inductor is smaller, and the dynamic load characteristic is better. Finally, based on theory analysise, experiment results are given.