输入并联输出串联的半桥变换器研究

Research on Input-paralleled Output-series Half-bridge Converter

在高输出电压、大功率的应用场合,单个变换器模块很难满足高输出电压、大功率设备的要求,存在变换器输入端功率器件电流应力过大,变换器次级电压偏高、整流二极管电压应力大和反向恢复时间长等问题。为此,以半桥变换器为基本单元,提出了一种适合于高输出电压、大功率应用场合的输入并联输出的串联半桥组合式变换器。该拓扑结构中各模块共用一对电容桥臂,这样大大减少了主电路中电容的数量,结构简单。分析了该组合式变换器的特点和规律,对其产生不均压不均流的因素进行了探讨并提出了相应的均压均流控制方案;进行了控制回路的设计,同时引进交错控制技术。仿真结果表明,它具有很好的均压均流效果及良好的输出特性,证明了该半桥组合式拓扑结构及其相应控制方法的正确性。

This paper proposes an input-paralleled output-series half bridge converter based on single half-bridge converter, it is suitable for the high output voltage and large power application. All modules share a common capacitorleg, so the converter can reduce the quantity of main circuit＇s capacitor and make topology simple. The traits and rules of combination converter are introduced. The reasons of no voltage-sharing and no current-sharing are discussed, and the corresponding voltage-sharing and current-sharing control method are presented and designed. Meanwhile, the interleaving control technology is introduced . Simulation results show that the effect of voltage sharing and current-sharing and output performance are better, the proposed topological structure of half-bridge combination and the corresponding control method are feasible .