A Strong Offset-Resistant Electric Vehicle Wireless Charging System Based on Dual Decoupled Receiving Coils

In an electric vehicle wireless charging system, the dramatic variation of the mutual inductance caused by the coil misalignment is an urgent problem to be solved. An offset-resistant wireless charging system based on dual decoupled receiving coils is proposed, with one receiving coil as the unipolar coil and the other as the quadrupolar coil. With series compensation, they are connected in series through the diode rectifier. In this way, the total equivalent mutual inductance is the summation of the absolute values of the two mutual inductances. Thus, the total equivalent mutual inductance can remain stable against misalignment, guaranteeing a stable system output. Experimental results confirm that the designed system has good misalignment tolerance capability in two perpendicular directions, enabling stable and efficient power transmission. Along the misalignment, the output voltage fluctuation is only 2.81% with the highest system efficiency of 94.68%.