金属异物对电动汽车无线充电系统影响分析

针对电动汽车在无线充电过程中可能混入金属异物的情况,本文分析了金属异物置于无线充电系统能量传输区域时对无线充电系统参数及效率的影响情况。研究中使用有限元仿真软件建立了电动汽车无线充电系统平面盘式螺旋线圈3D电磁场仿真模型,通过理论分析和有限元仿真结合的方式研究了不同尺寸、不同材质的金属异物对无线能量传输系统的电磁场参数以及效率的影响,并进行了实验验证。研究结果表明,两种金属混入系统会产生涡流效应和磁效应,磁效应和涡流效应会对无线充电系统参数产生不同的影响,降低系统效率;其影响大小与金属的尺寸和位置密切相关;此外,金属的涡流效应会产生涡流损耗并导致温升,对充电系统是极大的安全隐患。

Analysis of metal foreign object setting on electric vehicle wireless power transfer system

When wireless power transfer (WPT) technology is applied on the battery charging of electric vehicle (EV),the system's performance may be undermined if metal foreign object setting on the WPT system.Addressing this problem,this paper analyzes how metal foreign objects have an influence on the efficiency and parameter of the WPT system when it sets on the power transmission area.In this paper,a typical kilowatt-level magnetically resonant EV-oriented wireless charger model is built in finite element analysis software Comsol,and the magnetic field around the wireless charger and the parameters such as mutual inductance,resistor of coil are studied through circuit analysis and finite element analysis(FEA) when different size or different materials setting on the WPT system.The research shows that,different types of metal setting on the WPT system have magnetic effect and eddy current effect that have an impact on the parameter of WPT system and can reduce system efficiency,and the effect is related to the kind and the size of metal objects.Besides,eddy current effect of metal have an eddy current loss that cause a temperature rise of the metal,which is a security risk for the WPT system.