A Converter Research And Design For Inductive Power Transfer Applied To Small Guided Vehicles

As a technology of electric power transfer,inductive power transfer(IPT)has been extensively researched due to its series of advantages,and it has been applied to more and more aspects in actual life.In this paper,the power electronic converter device for IPT is researched,which aims to improve the efficiency and power density of the converter and increase the power supply efficiency.Taking the 2k W battery charger as an example,the design of the converter structure and circuit parameters is completed,the equivalent models are derived,the control methods of the converter are selected base on the equivalent models,and the IPT converter system is designed.Finally,simulation models and experimental platform are built to verify the design.In view of a series of problems such as low power density,high cost,and long charging time of vehicle batteries,the analysis shows that there is a huge market and broad prospects for IPT technology in solving battery energy storage problems.At the same time,the development and research status of IPT technology are introduced,and detailed investigation and analysis of the topology and control method for IPT are given.According to the specific application scenarios of logistics vehicles,the charging demand analysis of logistics vehicles is given,and the overall design index of the converter is designed based on the demand analysis.According to the overall design index of IPT converter,the PFC cascade DC/DC two-stage converter is selected as the overall design scheme after comparative analysis.According to the overall design scheme,the topology selection and modal analysis of PFC and DC/DC converters are carried out,and the control strategy is analyzed based on the selected topology.The complete design scheme of the circuit and the flow chart of the digital control program are given.The rationality of the designed converter is verified based on simulation and experiment.Since there are many control variables in the output power control of the post-stage DC/DC converter,the equivalent circuit is established by the first harmonic approximation(FHA),and the mathematical models of the transfer parameters are obtained.Based on the actual circuit parameters of this design,the models are calculated and drawn in MATLAB.Based on the waveforms,the effects of the two control variables,switching frequency and phase-shift angle,on the transfer parameters are analyzed.Through comparative analysis,phase-shift angle is selected as the control variable of this design.Simulation and experiment verified the feasibility of the movement control.Considering that the realization conditions of the soft switching of the inverter circuit are affected by various factors,the conditions for realizing zero voltage switching are derived based on the equivalent model of the DC/DC converter.By drawing three-dimensional graphs in MATLAB,the effects of dead-zone,primary side resonance capacitance,and the junction capacitance of MOSFETs on soft switching are analyzed.According to the conclusion,the primary side resonant capacitor and MOSFETs are selected,and the reasonable dead zone range is calculated.Simulations and experiments were carried out and verified.There are 74 figures,14 tables and 70 references in this thesis.