Theorizing and Demonstrating Far-Field Leakage Magnetic Field Reduction Using Adjacent Transfer Coils in Double-LCC Circuit for Dynamic Wireless Power Transfer

Several problems remain in the practical application of dynamic wireless power transfer to electric vehicles. It creates the leakage magnetic field that can be bad for people and devices nearby. There are some ways to make the leakage magnetic field smaller, like adding extra coils or materials, but they also add extra weight and cost. This paper proposes a new method to make the far-field leakage magnetic field at 10 m from the reference point smaller without additional equipment. This is a method of reducing the far-field leakage magnetic field by controlling the adjacent power transfer coils in the direction of travel of the power transfer coil that is transmitting power in a double LCC circuit. The currents flowing in the two transfer coils and the receiver coil are derived from the calculation of equivalent circuits considering the coupling between the coils. The effectiveness of the proposed method is confirmed by theoretical calculations using MATLAB and electromagnetic field analysis using Altair FEKO, and it is found that the far-field leakage magnetic field can be reduced below the regulated value without additional equipment.