Setting method for effective coupling range of wireless power transfer via coupled magnetic resonances.

According to the relationship between the output power and efficiency of wireless power transfer via coupled magnetic resonances system and the position and rotating attitude of coils, a method to define the effective coupling range is proposed in this paper. The equivalent mathematical model was established by using coupled-mode theory. The expression of system reception power and efficiency was deduced. The effective coupling point and effective coupling range were defined. Finally, the effectiveness of the method was verified by simulations and experiments. Results show that, within the effective coupling range of the system, no matter how the axial and radial positions of the transmitting and receiving coils change, there is always one or more axial rotation angles in the space which can enable the received power of the system to reach the critical coupling power, so as to ensure the efficient and stable power transmission of the system. [ABSTRACT FROM AUTHOR]