Research On Topology Design Of Multi-port DC-DC Converter

New energy power generation is an important way to solve the shortage of energy and environmental problems.Most new energy sources are vulnerable to the environment and have the shortcomings of discontinuous and unstable power supply.Therefore,new energy sources are often combined with energy storage units to improve the reliability of power supply.In new energy power generation system,the use of multi-port DC-DC converter can simplify the circuit structure,enhance the compactness and reduce system cost.In this paper,the topology generation and the combined optimization of topology of multi-port DC-DC converter are disscussed,and new multi-port DC-DC converters are proposed.In the paper,the basic pulsating source cells are extracted from the conventional bidirectional converters,and combined with the buffer cells to build multi-port converters.The approach to construct multi-port converters by the rule of combination among pulsating cells,the cascade of pulsating source cells and buffer cells.According to different rules,a series of multi-port DC-DC converters circuit topologies with different characteristics are derived.The topologies are simple,practical and have a wide range of application prospects.The reasonable and effective method of structure and optimization for multi-port DC-DC converter is applied.Taking the topological structure of three-port converter as an example,the preliminary three-port converter is constructed by combining conventional two-port converter,and then merge the branches with devices shared as much as possible to get an integrated and optimized topology.Taking the non-isolated converter as an example,the principle,method and process of constructing three-port converter from dual input,dual output and bidirectional converter are given respectively.The topologies of typical converters are verified by simulation.Based on the original power flow path of three-port converter,new multi-port non-isolated DC-DC converters are generated by increasing the power flow path or increasing the output load.Finally,Finally,the circuit model is built in the simulation platform,designing the reasonable parameters of the typical new multi-port DC-DC converters to analyse a variety of operating modes in detail,and the simulation results are given.