分布式储能中大降压比Buck变换器的优化设计

研究一种具有大降压比、低开关电压应力的新型Buck变换器,主要用于适配分布式储能系统中可再生能源输出与电池组之间的大压差。该变换器由低侧开关型降压单元与开关电感型降压单元级联而成。在介绍其工作模式和稳态特性的基础上，着重分析了变换器中各器件的功率损耗和电气应力，根据分析结果进行器件的优化选择和电路的优化设计。利用SIMPLIS软件进行仿真分析的同时，测试了一台峰值效率为94.6%、功率为750 W的实验样机。测试结果表明，该变换器具有极强的降压能力和较低的元件电气应力，同时能维持较高的变换效率。

Optimal Design of Buck Converter with Large Step-down Ratio for Distributed Energy Storage

To adapt to the large voltage gap between the output from renewable sources and battery banks in a distributed energy storage system, a novel Buck converter with a large step-down ratio and a low switch voltage stress is studied in this paper. This converter is formed by low-side switch step-down stage cascaded with switched-inductor step-down stage. Based on the introduction of its operation modes and steady-state characteristics, the power loss and electrical stress of its components are analyzed in detail. According to the analysis results, the optimal selection of components and the optimal design of circuits are performed. The SIMPLIS tool was employed to conduct simulations, and a 750 W experimental prototype with 94.6% peak efficiency was also tested. Test results demonstrate that an extremely high step-down capability and a low electrical stress of component can achieved by the proposed converter, and a relatively high conversion efficiency can be maintained.