Analysis Of The Influence Of Electromagnetic Force On The Operation Safety Of High-power Wireless Power Transmission System

For high-power wireless power transfer systems such as electric vehicles,highspeed railways and marine ships,due to the interaction of space magnetic field and high-frequency current,the coupling structures such as coil and magnetic shielding will be affected by electromagnetic force.Meanwhile,considering that metal foreign matters are easy to enter into the coupling area,the interaction between induced eddy current in metal and coupling magnetic field will also produce the effect of electromagnetic force.The existence of electromagnetic force will affect the stability of the coupling structure and the movement of metal foreign matters,even affects the operation safety of the system and the external environment.This paper analyzes the distribution characteristics of electromagnetic force on the coupling structure and the metal foreign objects,the dynamic characteristics of metals under the force have also been analyzed.First of all,from traditional electromagnetic force calculation methods,this paper deduces the analytical calculation model of the electromagnetic force on the coil and magnetic shield structure,analyzes the time-domain and frequency-domain characteristics of each electromagnetic force respectively.In this chapter,the transverse electromagnetic force on the coil causes the coil to deform,the longitudinal electromagnetic force makes the transmitting and receiving coils repel each other,the electromagnetic force on the magnetic shielding material is opposite to the direction of the coil electromagnetic force,which have been obtained.The steady and periodic component characteristics of the electromagnetic force is further analyzed,and the distribution characteristics of electromagnetic force at multiple power levels is verified through experiments,which are of great significance for improving the stability of the coupling structure.Secondly,in order to explore the mechanism of electromagnetic force acting on metal foreign objects,the analytical expressions of electromagnetic force on nonferromagnetic and ferromagnetic metals are derived respectively,and the direction,magnitude and influencing factors of electromagnetic force are explored.By constructing the circuit parameter equivalent model,the motion differential equation of metal foreign objects under the action of electromagnetic force is obtained,and the motion state and stability of metal foreign objects are further analyzed.Thirdly,the dynamic characteristics of different parameters and sizes of metal foreign objects under the action of electromagnetic force are simulated by setting up a multi physical field coupled finite element calculation model,combining the dynamic equation with the electromagnetic force equation.As well as the force and motion characteristics of different types and sizes of metal foreign objects at different positions are explored in this paper,the effects of metal velocity and heating on the system environment are analyzed.Finally,the dynamic characteristics of metal foreign objects measurement platform is built to verify the electromagnetic force characteristics of metal foreign bodies,and the movement of different types of metal foreign bodies such as displacement,acceleration and speed are measured and analyzed to verify the correctness of theoretical simulation.Furthermore,the influence of the electromagnetic force on the external environment and the coupling coil of the system is explored.In this paper,through the analysis of electromagnetic force of the coupling structure and the metal foreign objects in the high-power wireless power transfer system,the influence of the electromagnetic force on the system in different structures and metal foreign objects is explored,which has a positive reference significance for improving the safety and reliability of the system.