Research On Three Level DC/DC Converter Applied To Dynamic Wireless Power Transmission

In recent years,the government has accelerated the electric vehicle industry,and the sales of the electric car market are increasing.However,the promotion of electric vehicles is still heavy,and the charging time is long and the fast charging of electric vehicles needs more than half an hour;the charging is inconvenient,the public charging pile is not popular,the charging interface is not unified,and there is potential electric shock.It is dangerous.The battery price is high,and the weight and volume of the battery are not small.To solve the battery problem,dynamic wireless power supply technology has become a research hotspot.This paper mainly aims at the problem of high voltage in the side side of the dynamic wireless charging system.In order to improve the switching frequency to reduce the volume weight of the inductor and improve the energy density of the vehicle DC/DC converter,the three level Buck converter of the wireless charging receiver of the electric vehicle is studied.Based on the research background of electric vehicle wireless charging,the advantages of the three level Buck converter are combined with it.The purpose is to optimize the performance of the electric vehicle wireless power supply system.On the basis of theoretical analysis,a set of three level Buck converters applied to the dynamic wireless power supply technology of electric vehicles is designed.Firstly,from the point of view of the whole system,the coupling mechanism is briefly analyzed,the topology matching principle of the system and the parameter fluctuation of the dynamic wireless power supply system are analyzed in detail.The working principle and control strategy of the three level Buck converter are expounded,and the small signal modeling is carried out,and the angle of the impedance analysis is studied.The study should be applied to the power and efficiency of the three level Buck converter in the dynamic wireless power supply system.The characteristics and advantages of the cascade of three level Buck converters to the wireless charging system should be summarized.Secondly,based on the proposed topology and the design requirements given by the system,the overall hardware design of the system is completed.The design of the chopper inductor is particularly critical.In the design process,the volume weight of the inductor is reduced and the power density is improved compared to the traditional Buck converter.On this basis,the hardware circuit design of the system control board and the adjustment board is completed.The selected IGBT module is designed for the radiator and the heat simulation experiment is carried out.At the same time,in order to reduce the voltage and current peak,the stray inductance simulation analysis is carried out according to the bus line capacitance of the bus line,and the advantages and disadvantages of different line ways are compared..Finally,the simulation model of the whole dynamic wireless power supply system is established and analyzed.At the same time,the closed loop simulation design and analysis of the three level Buck converter are carried out.The experimental platform of the three level Buck converter is designed and made,and the related characteristics test is completed with the dynamic wireless charging system,and the experimental results are in line with the expectation.