Design and realization of a four coils excited wireless power transmission region via magnetic resonances

Wireless power transmission region stands out for its convenience in the applications where several terminals or movable terminals need to be charged. The conventional single coil excited charging region has the drawback of distance and angle limitation. To overcome the shortcoming, a charging region which is constructed by four emitting coils is proposed in this paper. This four emitting coils configuration can not only increase the transmission distance but also weaken the sensitivity to angle change. Regarding the emitting coil as magnetic pole, four windings connection types of these four emitting coils are put forward. By both theoretical analysis and software simulation, magnetic field distributions of these four windings connection types are studied and the S-S-N-N is finally selected as the windings connection type. The equivalent circuit for this configuration is derived and the parameter design method is further presented. Finally, a 0.8×0.8×0.8 m³ wireless power transmission region with four emitting coils via magnetic resonances is fabricated in the lab and the experimental results can verify the correctness of parameters design and the effectiveness of the proposed four coils excited charging region.