Optimization Design And Research On Control Based On LCC-S Type Wireless Transfer System

As an energy form of economical,clean,easy to be controlled and converted,electric energy plays an extremely important role in people's production and life.With the improvement of social economic level and the progress of science and technology,the shortcomings of traditional wired transmission way of electric power restrict the application of electric energy more flexibly and extensively.Wireless power transfer technology emerges as the times require.It has a broad development prospect because of its small area,strong adaptability,flexible and convenient.At present,Wireless power transfer technology has been gradually applied in the fields of consumer electronics,household appliances,electric traffic,implantable medicine and so on.Among them,the magnetic coupling wireless power transfer technology,which is applied to electric traffic wireless charging,is developing rapidly.The related technology standards and demonstration applications are gradually coming into people's vision.In this paper,the transmission characteristics and power control of a magnetic coupled LCC-S type wireless power transfer system are studied.First of all,this paper summarizes the current development trend of wireless power transfer technology from its basic classification and principles,vehicle related technology standards,theory and application status.Then,the configuration method and the input and output characteristics of the equivalent circuit of the compensation structure are analyzed.And the LCC-S type compensation network is configured based on the traditional basic compensation topology.Secondly,the mathematical model of LCC-S wireless power transfer system is set up,and multiple work modes which can operate stably and have application value,are put forward.The work modes are compared and analyzed from various aspects of the inverter output current distortion,component stress,transmission efficiency,output power and output gain.Then,the multi-objective optimization model of the system is established considering the application requirements of the actual system.The running frequency of these work modes are searched based on the multi-objective genetic optimization algorithm,and these work modes are verified from the optimization point of view.Thirdly,the multi-objective genetic optimization of the compensation network parameters is carried out considering of the parameter drift of the compensation element in the actual system.Fourth,the experimental platform of magnetic coupling wireless power transfer system is designed,and some problems and solutions in the process of hardware design are briefly introduced.At the same time,based on the experimental prototype,the transmission characteristics of the LCC-S type wireless power transfer system are verified by experiments,which is basically consistent with the theoretical and simulation results,and the characteristics of constant current and constant output voltage are achieved under the mode of magnetically coupled resonance.In addition,the system performance in the case of parameter drift are analyzed experimentally.Finally,the basic requirements of power control and the advantages and disadvantages of the existing control methods are analyzed.The constant voltage control scheme using a non-isolated four switch up-down voltage converter is determined.The hardware design process of this converter is also introduced.The constant voltage control experiment based on this converter has achieved good control performance,under the change of load and coupling conditions and the drift of compensation element parameters.