TY - GEN
T1 - Metal Foreign Matter Detection and Hazard Elimination Based on Passive Shield of Monitor Coils
AU - Sun, Ying
AU - Song, Kai
AU - Zhou, Tian
AU - Wei, Guo
AU - Zhu, Chunbo
N1 - Publisher Copyright:
© 2023, Beijing Paike Culture Commu. Co., Ltd.
PY - 2023
Y1 - 2023
N2 - Aiming at the detection needs of metal foreign matters in high-power wireless charging system, a method of metal foreign matter detection based on the impedance change of monitor coil has been proposed. By the monitor coil array laying on the surface of transmitter coil and monitoring its impedance change, the presence and location of metal matters could be detected. Also, a method to eliminate the harm of metal matters based on the passive shielding of monitor coil is proposed. Benefitting from the induced current inside monitor coil, the magnetic field and the heat of metal matters are reduced effectively which guarantee the normal charging process in presence of metal matters. Firstly, the mutual inductance coupling model of metal matter and monitor coil is built, and the detection principle based on the change between monitor coil impedance is demonstrated. Then the relationship between power loss and magnetic induction intensity is analyzed, and a passive shielding circuit is designed. Finally, experimental verification was carried out on a 3.3 kW wireless charging prototype, and the detection system could accurately detect the existence and location of 1-yuan coin. Under the continuous operation of wireless charging system and the shielding effect of monitor coil, its equilibrium temperature drops from 83.4 ℃ to 62.2 ℃, which is lower than the safety threshold of 80 ℃ in the current standard, ensuring the continuity of wireless charging process and system security.
AB - Aiming at the detection needs of metal foreign matters in high-power wireless charging system, a method of metal foreign matter detection based on the impedance change of monitor coil has been proposed. By the monitor coil array laying on the surface of transmitter coil and monitoring its impedance change, the presence and location of metal matters could be detected. Also, a method to eliminate the harm of metal matters based on the passive shielding of monitor coil is proposed. Benefitting from the induced current inside monitor coil, the magnetic field and the heat of metal matters are reduced effectively which guarantee the normal charging process in presence of metal matters. Firstly, the mutual inductance coupling model of metal matter and monitor coil is built, and the detection principle based on the change between monitor coil impedance is demonstrated. Then the relationship between power loss and magnetic induction intensity is analyzed, and a passive shielding circuit is designed. Finally, experimental verification was carried out on a 3.3 kW wireless charging prototype, and the detection system could accurately detect the existence and location of 1-yuan coin. Under the continuous operation of wireless charging system and the shielding effect of monitor coil, its equilibrium temperature drops from 83.4 ℃ to 62.2 ℃, which is lower than the safety threshold of 80 ℃ in the current standard, ensuring the continuity of wireless charging process and system security.
KW - Metal foreign matter detection
KW - Passive shielding
KW - Thermal equilibrium temperature
KW - Wireless power transfer
UR - https://www.scopus.com/pages/publications/85152615589
U2 - 10.1007/978-981-99-0408-2_96
DO - 10.1007/978-981-99-0408-2_96
M3 - 会议稿件
AN - SCOPUS:85152615589
SN - 9789819904075
T3 - Lecture Notes in Electrical Engineering
SP - 885
EP - 897
BT - The Proceedings of the 17th Annual Conference of China Electrotechnical Society
A2 - Xie, Kaigui
A2 - Hu, Jianlin
A2 - Li, Jian
A2 - Yang, Qingxin
PB - Springer Science and Business Media Deutschland GmbH
T2 - 17th Annual Conference of China Electrotechnical Society, CES 2022
Y2 - 17 September 2022 through 18 September 2022
ER -