Power transfer efficiency for distance-adaptive wireless power transfer system

In this paper, a highly efficient distance-adaptive wireless power transfer system with automatic impedance tuning control at variable distances is proposed, and we compare the power transfer efficiency of wireless power transfer system at different operating conditions using the method of moments (MoM) technique. By sensing a reflected power and controlling impedance tuning networks, the proposed wireless power transfer system achieves the high and stable efficiency with regard to the variable operating distances. According to adaptive impedance matching algorithms under the minimum reflected power conditions, the proposed system achieves an improved power transfer efficiency of approximately maximum 160% within the operating distance.