基于开关流图法的高阶DC/DC变换器建模

Modeling of high⁃order DC/DC converter based on switching flow graph method

为满足DC/DC变换器在新能源光伏发电等领域应用的需求,研发了多种新型拓扑结构。由于其新型变换器阶数显著高于传统变换器的,导致增大了变换器建模和设计的难度,为此该文以四阶Zeta变换器为研究对象,探索基于开关流图的高阶变换器建模新方法。在开关周期内导通和截止状态开关流图的基础上,建立变换器开关流图,进而推导开关支路和变换器的小信号模型,最后采用PSIM仿真验证模型的正确性。仿真结果表明该文设计的高阶DC/DC变换器具有较高的参考价值。

In order to meet the demand of DC/DC converter in the field of new energy photovoltaic power generation and other fields,a variety of new topological structures have been developed.The order of the new type of converter is obviously higher than that of the traditional converter,so the modeling and design difficulties are increased.For this reason,the fourth⁃order Zeta converter is taken as the research object of this paper to explore a new modeling method of higher⁃order converter based on switch flow diagram.On the basis of establishing switching flow diagrams of turn⁃on and cut⁃off states in one switching period,a converter switching flow diagram is established,and then the small signal model of switch branch and converter is derived.The correctness of the model was verified by PSIM simulation.The simulation results show that the system designed in this paper has a reference value for the design of new high⁃order DC/DC converters.