In the last decade, engineers from automotive manufacturers and charging infrastructure suppliers have widely studied the application of wireless power transfer (WPT) technology to electric vehicles. Since this time, engineers from automotive manufacturers have studied precise positioning methods suitable for WPT using methods such as mechanical, communication-based or video-based. However, due to high costs, electromagnetic interference and environmental factors, the experts of the SAE J2954 was focused on the WPT’s precise positioning method by ferrite antennas and low power excitation. In this study, we present how to use the ferrite antennas to find a central alignment point between the primary and secondary units within the alignment tolerance area that requires the minimum power transfer efficiency of the EV WPT system. First, we analyze the ferrite antenna already applied in the automotive and verifies whether it is suitable for the precise positioning of the WPT system for EV. We use modeling and simulation to show that it is necessary to calculate all induced loop voltages in the relationship between incident magnetic field signal strength and induced loop voltage because of the short distance between the transmitter and receiver of the ferrite antenna in WPT. In addition, we also suggest a sequence to find the fitting location of the ferrite antenna, the number of antennas used and the center alignment point. After the simulation is performed on the suggestions, component-level and vehicle-level tests were conducted to verify the validity of the simulation results. As a result, it is shown that a ferrite antenna is suitable as a method for the secondary device to find the center alignment point of the primary device.

中文翻译：

---

基于铁氧体天线的电动汽车无线电力传输系统的精确定位研究

在过去的十年中，汽车制造商和充电基础设施供应商的工程师广泛研究了无线电力传输（WPT）技术在电动汽车中的应用。从那时起，汽车制造商的工程师就使用机械，基于通信或基于视频的方法研究了适合WPT的精确定位方法。但是，由于成本高昂，电磁干扰和环境因素，SAE J2954的专家专注于通过铁氧体天线和低功率激励实现WPT的精确定位方法。在这项研究中，我们介绍了如何使用铁氧体天线在对准容差区域内的初级和次级单元之间找到一个中心对准点，该中心对准点要求EV WPT系统的最小功率传输效率。第一，我们分析了已经在汽车上使用的铁氧体天线，并验证它是否适合电动汽车WPT系统的精确定位。我们通过建模和仿真表明，由于WPT中铁氧体天线的发射器和接收器之间的距离很短，因此有必要计算入射磁场信号强度与感应环路电压之间关系中的所有感应环路电压。此外，我们还建议了一个顺序，以找到铁氧体天线的安装位置，使用的天线数量和中心对准点。在根据建议进行仿真之后，进行了组件级和车辆级测试以验证仿真结果的有效性。结果是，