一种新型大功率输入并联输出串联Buck半桥变换器

现有的升降压拓扑中双管Buck-Boost和双管Boost-Buck变换器较符合高效大功率场合的使用要求,前者结构简单,但电流纹波大;后者引入了2个电感,功率密度很难提高。提出了一种新型大功率并联输出串联Buck半桥变换器(input-parallel output-series Buck-halfbridge,IPOSBHB),分析了IPOSBHB的电路结构、工作原理及基本关系,并从电压电流应力、磁性元件总体积、效率这3个方面与双管Boost-Buck变换器做了对比,提出了一种基于组合开关方式的控制策略,实现了升降压的模式切换和恒压、恒流的输出特性,最后通过1台15 kW样机对所提出的理论进行了验证。

A Novel High-power Input-parallel Output-series Buck-halfbridge Converter

Two-switch Buck-Boost and Boost-Buck converter are the most appropriate solutions for efficient high-power applications in existing topologies.The former structure is simple,whereas the current ripple is large.The latter introduces two inductors,thus the power density is difficult to improve.A novel high-power input-parallel output-series Buck-halfbridge(IPOSBHB) converter was proposed in this paper.The circuit structure,working principle and basic relations were analyzed.A comparison of IPOSBHB and Boost-Buck cascade converter was also elaborated including voltage and current stress,the total volume of magnetic components and efficiency.A combinatorial control strategy was proposed,thereby the Buck-Boost operation mode transition and constant voltage and current output characteristics were realized.The proposed theory is validated by a 15 kW prototype.