Coupling Coil Parameters Design Method For WPT Systems Based On M-k Combination Optimization

Wireless Power Transfer(WPT)technology has the advantages of safety,convenience,and able to use in harsh environments.It is increasingly adopted as the electric vehicles,rail transportation,household appliances,military and others,and has become one of the focus researches in recent years.Coupling coils as one of the core parts of Wireless Power Transfer technology.The coupling coil parameters have directly affected the power,efficiency and transmission distance of the Wireless Power Transfer system.And affect the wire selection of the coupling coil?resonant Capacitance and Application of Wireless Power Transfer technology in Engineering.In this paper,the existing design of coupling coils parameters are analyzed,the research on the unclearness and irrationality of coupling coils design in project.Aiming at the unreasonable problem of the existing design method of coupling coil parameters,a design method of coupling coil parameters based on M-k combination optimization is proposed.The software MATLAB is used to program the design method.When the parameters of system performance are input,such as system power,efficiency,coupling distance,coil size,working frequency,input voltage,can output a set of coupling coil parameters that meet the system performance requirements and have the largest coupling coefficient.The output parameters include the self-inductance coefficient,mutual inductance coefficient,coupling coefficient,resonant current,resonant voltage,coil internal resistance and winding position information of the primary and secondary coils.In order to improve the design method of coupling coil parameters,this paper briefly summarizes the research status of coupling coil parameter design methods at home and abroad,and analyzes and studies its related theory.And solving the problem of coil radius selection,the influence of the electromagnetic theory of coupling coil and the size and position of the coil on the magnetic field is analyzed,and a method of determining the maximum radius of the primary coil by the maximum flux density point is proposed.The maximum coupling coefficient point is used to determine the maximum radius of the auxiliary coil,and the contribution rate of the mutual inductance coefficient between coils is used to solve the problem of selecting the minimum radius of the coil.In addition to solving the problem of coil radius,the calculation method of coil internal resistance,the influence of coupling coil parameters on system power and efficiency,and the engineering constraints of coupling coil are analyzed.Finally,the simulation software and experimental results based on COMSOL verify the correctness of the theory.The design of coupling coil parameters based on M-k combination optimization is presented in this paper,which provides the design idea and theoretical basis for the design of coupling coil parameters.The user only needs to input some necessary parameters of the system performance to get all the parameters of the coupling coil,thus reducing the workload of the design of the coupling coil.The method can also be used to determine whether the performance requirement of the system is reasonable or not,and to optimize the coils with magnetic core structure coupling coils.Therefore,the research content of this paper has important reference value and significance in the parameter design of coupling coil.