双向DC/DC变换器轻载损耗和效率最优化分析

Optimization analysis of power loss and efficiency of bidirectional DC/DC converter at light load

双向DC/DC变换器的轻载效率问题一直是困扰设计者的一大难题。为在轻载情况下减小损耗,提高效率,对以交错并联为拓扑结构的双向DC/DC变换器工作中的功率损耗进行了综合性地分析和研究。以两相Buck+Boost交错并联双向DC/DC变换器运行在Buck模式下作为模型,分析和推导了电感电流断续模式(DCM)和电感电流连续模式(CCM)下的功率损耗公式,对其在轻载情况下的工作频率进行最优化调整,从而给出了使损耗达到最小化的设计准则。通过实验验证了理论分析的正确性,为多相交错并联双向DC/DC变换器提高轻载效率的设计提供了理论基础。

It was difficult work for designer conceming light-load efficiency of bidirectional DC/DC converter. Comprehensive analysis and research towards the power loss of interleaving topology circuit on bidirectional DC/DC converter were presented to reduce power losses and improve efficiency at light load. With two-phase Buck＋Boost interleaving bidirectional DC/DC converter operating in Buck mode as a model, power loss formula in DCM and CCM mode was analyzed and derivated. Meanwhile, the design criteria that two-phase Buck＋Boost interleaving bidirectional DC/DC converter adjusted working frequency was given. Thus the power loss under different loads was minimized. Through the experimental results, the validity of the theoretical analysis, which provides theory basis to improve the efficiency of the light load for multiphase interleaving bidirectional DC/DC converter, was verified.