电动汽车无线充电系统的精确定位方法

Fine Positioning Method for Wireless Charging System of Electric Vehicles

在电动汽车无线充电的应用中,车辆定位引导功能对保障充电效率十分重要。当定位距离较近时,基于磁偶极子模型的传统定位方法误差较大。为此,提出一种优化的近距离精确定位方法。首先,基于无线充电系统的原边线圈,提出了一种可精确描述空间磁场分布的方形线圈模型,并给出了等效边长的计算方法;然后,提出了基于非线性最小二乘法的定位算法;最后,通过仿真和样机实验,验证了该方法的可行性。仿真和实验结果表明,与基于磁偶极子模型的定位方法相比,该方法定位精度更高,并在车身有小角度偏转的情况下,仍然可以保持较高的定位精度,并且当定位距离较近时,该方法的定位误差小于0.03 m,适用于电动汽车无线充电系统的精确定位。

In the wireless charging system of electric vehicles,positioning function is of the great importance to ensure the charging efficiency.When the positioning distance is short,the traditional positioning method based on the magnetic dipole model has a large error.For this reason,an optimized method of accurate location at close range was proposed.Firstly,based on the origi⁃nal side coil of wireless charging system,a square coil model which can accurately describe the spatial magnetic field distribution was proposed,and the calculation method of equivalent side length was given.Then,the positioning algorithm based on nonlinear least squares method was proposed.Finally,simulation and experiments verified the proposed method.The simulation and experi⁃ment results show that,compared with the positioning method based on magnetic dipole model,the proposed method has higher positioning accuracy and can maintain high positioning accuracy even when the vehicle has a small yaw angle.Besides,when the positioning distance is short,the positioning proposed error of the method is less than 0.03 m,which is suitable for precise positio⁃ning of electric vehicle wireless charging system..