Three-phase Inductive Power Transfer System with 12 coils for Radiation Noise Reduction

A three-phase inductive power transfer system with six transmission coils and six receiving coils is proposed in this paper. The proposed system achieves a reduction in radiation noise by canceling the noise using multiple coils, which are placed opposite to each other. However, in IPT systems with multiple coils, a magnetic interference among the multiple coils decreases a transmission efficiency due to the occurrence of circulating current. The proposed three-phase IPT system achieves cancellation of the interference using six coils on each side. First, the IPT system with the 12 coils is proposed. Then, a canceling condition of the magnetic interference among the coils is mathematically introduced from the voltage equation on the coils. Finally, the proposed IPT system is experimentally demonstrated with the 3-kW prototype. The experimental result shows that the radiation noise at the fundamental frequency is suppressed to 1/6 (from 12.2dB mu A to 2.1dB mu A).