Foreign Object Detection of Wireless Power Transfer System Using Sensor Coil

Wireless Power Transfer (WPT) system are used in many areas due to their advantages such as safety, aesthetics, and convenience. The WPT system are being applied not only smartphones that are common around us, but also to various electronics and medical devices. In particular, in the case of Electric Vehicle (EV), researches are steadily underway to apply the WPT system to solve the problem of battery dependence. Inductive power transfer (IPT) is the most popular WPT method to transfer power using the magnetic field. However, Foreign Object (FO) in WPT system can be heated by strong magnetic field and can lead to fires. Also, it can reduce power transfer efficiency. The risk of fire in a WPT system such as EVs, which require large power, is a major obstacle. Therefore, FO detection method is necessary for the safety and good performance. In this paper, we propose a Foreign Object Detection method using sensor coils. The proposed method is simple and shows the good performance compared with conventional method.