Basic Investigation on Wireless Power Transfer System via Magnetic Resonant Coupling with Magnetic Field Suppression at an Any Point

In recent years, attention has been drawn to wireless power transfer of an electric vehicle via magnetic resonance coupling as a transmission method. Although the wireless power transfer enables to reduce the risk of electric shock and the loss of time for connecting the power cable, there are problems that underlie in leakage of magnetic field generated along with the wireless power transfer, absorbed by surrounding objects. Therefore, in this paper, we investigated the number and allocation of the coils of the phased array coil which we believe to have the potential of suppressing the magnetic field absorption while maintaining the transmission efficiency. The optimization of the phased array coil arrangement and the phase and amplitude of the input voltage was done using the Particle Swarm Optimization (PSO). As a result, there were five variations in the arrangement of the RX coil, and the most effective magnetic field suppression was achieved in the configuration with two TX coils, and the magnetic field was suppressed by -83.4%, compared to the configuration of a general MRC-WPT.