Inductive Coils Coupling and Circuit Analysis of Wireless Recharging

• Main Authors: Yu-Hsiu Liu, 劉禹秀
• Other Authors: Yih-Peng Chiou
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/48976959476583191551

碩士 === 國立臺灣大學 === 光電工程學研究所 === 99 === Safety and convenience become one of the considering factors of consumption with the prevalence of portable electrical products nowadays. Besides disorderliness and inconvenience, traditional recharging devices with cables still have many problems such as electrocution, fire caused by electricity, etc. In order to solve these problems, development of wireless recharging technology brings in a brand new design concept. We can recharge portable electrical devices safely and conveniently by just putting them on the recharging platform. However, the main difficulty is the low efficiency of electric power transfer without cables as transferring media. Therefore, in the thesis, we analyze the inductive circuits of wireless recharging device proposed by Wireless Power Consortium, and derive the efficiency of effective power transfer between each circuit layer and use electromagnetic simulation software—Maxwell 3D—to simulate coupling coefficients of two inductive coils, which are key points of electric power transfer. The part of circuit analysis is about transmitting and receiving circuit, we analyze the power transfer efficiency of two resonant circuits which have complex impedances in the frequency domain. Then we simulate two coil structures—vertical helix coils and horizontal helix coils, incorporated with additionally auxiliary magnetic shieldings to improve coupling coefficients, to compare effects of electromagnetic coupling analyzed by Maxwell 3D software. Finally, we wind two structures made by coils mentioned above to measure the coupling coefficients and calculate the power transfer efficiency of simplified inductive circuit for coils with magnetic shieldings.