Optimization spatial multiple coil transmitter structure for wireless power transfer

The contactless charging system has a wide application range and many advantages for portable consumer electronic products. Wireless power transfer (WPT) includes both the transmitter and the receiver which are in the state of resonance to achieve high efficiency. This paper presents a new multiple overlapping coil transmitter structure which enables the receiver has high efficiency within transmitter center area in a freedom of movement manner. The optimization novel transmitter structure can achieve higher efficiency than the typical single coil. Simulation results show that the axial component of magnetic induction resulting from the overlapping coil structure has a preferable homogeneous distribution. The proposed optimization system achieves the efficiency of 60% for a receiver placed 10 cm away from a 4 coil (four overlapping coil) transmitter.