改进型交错并联Buck变换器的通道控制

Improved Phase-shedding Control of Interleaved Buck Converter

交错并联Buck变换器采用通道控制能有效提高变换器的轻载效率,但是减小导通通道数后,总输出电流纹波显著增加,基本丧失了交错并联的优点。针对这一问题,提出一种改进型的交错并联Buck变换器的通道控制方案,随着负载电流的减小,改变导通通道数的同时改变各通道控制脉冲的相位,在提高变换器轻载效率的同时,减小输出电流纹波,使交错并联技术在通道控制中的优点发挥到最佳状态。以4相交错并联Buck变换器为例,通过仿真和实验验证理论分析的正确性。

The interleaved Buck converter can effectively improve its light-load efficiency using phase-shedding control.However,the total output current ripple will significantly increase after the number of conduction phases is reduced,thus the advantages of interleaving are almost lost.To solve this problem,an improved phase-shedding control scheme for the interleaved Buck converter is proposed in this paper.As the load current gets lighter,the number of conduction phases will be changed together with the variation of the phase of control pulse in each conduction phase.In this way,the output current ripple is reduced together with the improvement of the converter’s light-load efficiency.Accordingly,the advantages of interleaving technology under phase-shedding control are maximized.A four-phase interleaved Buck converter was taken as an example,and the validity of the theoretical analysis was verified by simulation and experimental results.