Effect and Influence of Double Resonance Couplings With Dual Resonance Frequencies for Wireless Power Multi-Charging Module in Superconducting MAGLEV Train

The wireless power charging (WPC) system based on the resonance coupling method, which is composed of separate coils with same resonance frequency, is feasible for exchanging electric energy within 2 m. We have been developed the WPC unit for high speed superconducting magnetic levitation (MAGLEV) train to improve the transfer efficiency and stability since the WPC system can supply electric power without overhead wire power lines of pantographs. Practically, the various WPC units have been required in the super high speed transportation systems since it can reduce the construction cost of pantographs as well as multi charging units to inside and outside of traveling train. From this point of view, authors proposed the enhanced WPC system using multi antenna (Tx) coils with dual-resonance frequencies to expand the practical way. As the multi Tx and multi-receiver (Rx) coils of WPC unit are intrinsically sensitive to impedance variation from external factors such as double resonance coupling coils and the electromagnetic propagations, the effect and influence of charging characteristics for double resonance coupling coils with dual-resonance frequencies should be exanimated. In this paper, the effect and influence of charging characteristics and thermal distributions were investigated under the different resonance coupling modeling with 370 and 750 kHz power sources. In addition, the effect of reflected power at Tx coils was investigated under double resonance coupling coils.