Research On Boost-type LLC Resonant Converter For Hydrogen Fuel Cell Power Generation

In recent years,hydrogen fuel cell has attracted great attention because of its advantages such as zero pollution,high operation quality and good flexibility,and there are more and more researches on hydrogen fuel cell energy conversion system.The output power of hydrogen fuel cell is affected by the working efficiency of its converter,and the working efficiency of the converter directly affects the overall efficiency of hydrogen fuel cell energy conversion.Therefore,the research on the DC converter used in hydrogen fuel cell is of great significance to give better play to the advantages of hydrogen fuel cell.After comparison and analysis,this paper finally chooses Boost-type LLC resonant converter as the DC converter of hydrogen fuel cell power generation system,and carries out a series of research work on hydrogen fuel cell power generation system and Boost-type LLC resonant converter.Firstly,the output power characteristics of hydrogen fuel cell are analyzed.The working principle of hydrogen fuel cell is introduced,the mathematical model of hydrogen fuel cell is established,and the characteristics of hydrogen fuel cell are analyzed by theory and simulation experiments.According to the output characteristics of hydrogen fuel cell,the main requirements of DC converter in hydrogen fuel cell power generation system are obtained.Secondly,the Boost-type LLC resonant converter is studied theoretically.The working principle of the converter is introduced,and the gain of the converter is analyzed by fundamental wave analysis method and time domain analysis method,and then the input current ripple,Boost inductor current sharing and soft switching characteristics of the converter are analyzed.Through the theoretical research in this chapter,it is proved that the Boost-type LLC resonant converter meets the main requirements of the converter in the hydrogen fuel cell power generation system,and the converter is suitable to be used in the hydrogen fuel cell power generation system.In addition,the loss analysis and parameter design of Boost-type LLC resonant converter are carried out.Firstly,the influence of converter parameters on loss is analyzed,and then the loss model of each part of the converter is obtained.Finally,the parameter design flow chart is given according to the relationship between converter parameters and loss.A set of converter parameters are determined according to the converter specifications in this paper.Finally,the simulation and experimental study of Boost-type LLC resonant converter for hydrogen fuel cell power generation are carried out.Firstly,the Boost-type LLC resonant converter is simulated and analyzed,and the simulation results are basically consistent with the theoretical analysis,which verifies the wide input voltage adaptability,low input current ripple characteristics,soft switching characteristics and good voltage stabilization in the case of sudden load change.Then,with the help of DC microgrid experimental platform,the experimental analysis of hydrogen fuel cell power generation system is carried out,and the experimental results are consistent with the theoretical analysis and simulation results.