三电平Buck-Boost双向变换器的仿真研究

双向DC-DC变换器因其在提高系统容错能力和降低系统重量等方面有重要应用价值而受到人们广泛重视；三电平变换器由于其低的开关管电压应力，应用在高压场合具有明显优势。本文中提出两种三电平Buck-Boost双向变换器拓扑及其交错互补控制方案，根据占空比及电感电流的不同变换器共有9种不同的工作方式，并以输入输出共地式变换器在D〉0．5下的三种典型工作方式为例，对该类变换器的工作原理进行了阐述，推导了基本关系，通过仿真验证了控制方案的可行性。

Simulation Research on Three-Level Buck-Boost BiDirectional Converter

With the ability of the bi-directional power flow, the bi-directional dc/dc converter has been used extensively and the threelevel converter has been attracting more and more attentions for its half voltage stress of the switches. In this paper, two three-level buck-boost hi-directional dc/dc converters and a novel interleaving control strategy for them are proposed. The kind of the three-level buck-boost hi-directional dc/dc converter has 9 different operation modes when duty cycle and inductor current are different. The operation of the three modes under the conditions that duty cycle is greater than 0. 5 is detailed. Some fundamental formulas are deduced. Thus,the feasibility of this control strategy is verified and the research work covered in this paper lays a profound foundation for further research.