As the application scenarios of wireless charging technology become more extensive,the tra-ditional one-to-one charging form of transceiver coils with the same size cannot meet the needs of produc-tion and life any more.Wireless charging still has certain problems in some special scenarios,particularly for energy transmitting from larger transmitting coils to smaller receiving coils.Position difference of the receiving device in wireless charging area often result in substantial charging efficiency fluctuations.To ad-dress this issue,a"non-uniform"transmitting coil with unequal turn spacing is proposed.Utilizing the e-quivalent circuit model of wireless energy transmission systems,the influence factors on system transmis-sion efficiency are analyzed;combining the Wheeler formula,the relationships between the system efficien-cy with turn spacing,coil self-inductance,and mutual inductance are derived,respectively.To optimize the transmission efficiency of the receiving device at different positions in wireless charging area,local turn spacings in the transmitting coils are adjusted to ensure a relatively uniform distribution of self-inductance.Consequently,the mutual inductance of the coupling coil is stabilized,thereby the system transmission ef-ficiency is improved and stabilized to a certain extent.The simulation and experiment show that,at a transmission distance of 10mm,the fluctuation in transmission efficiency remained within 17.4%as the re-ceiving coil shifted 100mm from the center position to the edge.In comparison to a transmitting coil with equal turn spacing,this design effectively improves the offset resistance of the system.
关键词
无线充电/匝间距/磁场均匀/抗偏移/传输效率
Key words
Wireless charging/Turn spacing/Magnetic field uniformity/Offset resistance/Transmis-sion efficiency
维普
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