Research On A High-gain DC-DC Converter Based On A Dual-tube Structure

The development of the modern industrial society has long relied on fossil fuels for energy supply,but due to the non-renewable nature of fossil fuels and the use of combustion will emit a lot of polluting gases.Countries around the world are vigorously developing photovoltaic power generation technology.The output voltage of a single photovoltaic power generation module is low.Therefore,a high-gain,high-efficiency boost converter is required to increase the output voltage to meet the input voltage requirements of the subsequent inverter.Compared with traditional Boost converters,dual-switch boost DC-DC converters have the advantages of high gain and low switching stress.Based on this,this paper studies the dual-switch boost converter.(1)According to the existing research literature at home and abroad,the non-isolated DC-DC boost converter is reviewed,the topology of the boost DC-DC converter is classified,the idea of the combination of topological structures is summarized,and the voltage gain and switching are pointed out.The voltage stress of the device,the average current of the inductor and the scalability are the key factors that determine the performance of the converter,and are also the research focus of the new boost converter.(2)The working principle of the dual-switch DC-DC boost converter is analyzed.In the continuous conduction mode and discontinuous conduction mode energy transmission process,the boundary conditions of the critical mode are given,and the voltage gain expression in different modes is calculated.Compared with the traditional Boost converter,the characteristics of voltage gain,switch tube voltage stress,average inductance,etc.The results show that the gain performance of the dual-switch DC-DC boost converter is not obvious,and the shortcomings of excessive output diode voltage stress are verified by simulation.result.(3)In view of the shortcomings of insufficient gain performance and excessive output diode voltage stress of the dual-switch DC-DC boost converter,the idea of topological structure combination is applied,and a switching inductor unit is introduced to replace the ordinary single inductance structure to form a dual-switch boost with switching inductor Converter.The working principle and circuit characteristics of the proposed converter are analyzed in detail and verified by circuit simulation.Theoretical analysis and circuitsimulation results show that the proposed converter can effectively improve the voltage gain performance and reduce the voltage stress of the switching device.(4)For the shortcomings of too many devices after the switch inductor unit is introduced,capacitors are used to replace part of the diodes to form an improved switch inductor dual-switch boost converter.Without increasing the number of components,further improve performance.The energy transfer process of different conduction modes is analyzed,and the boundary conditions of the critical mode are given,compared with the performance of the aforementioned converter,and the theoretical analysis results are verified by simulation.The results show that the improved switched inductor dual-switch boost converter has better performance.The state-space averaging method is used to model the improved switched-inductor dual-switch boost converter,and the transfer function is obtained.The closed-loop control compensation network is designed according to the transfer function.The circuit simulation results show the effectiveness of the closed-loop control system.