13.56 MHz Scalable Shielded-Capacitive Power Transfer for Electric Vehicle Wireless Charging

This paper proposes a scalable shielded capacitive power transfer (shielded-CPT) for mini electric vehicle (EV) wireless charging application. The design and analytical studies of the proposed shielded-CPT are introduced by using LTSpice™ simulation software. In order to obtain an accurate calculation of the impedance matching network, the capacitances appeared in the system are observed with finite element analysis (FEA) tools using ElecNet™ software from Infolytica™. With a 3-cm shield-shield gap, 3.46 pF of coupling capacitance and 10.9 pF of shield coupling capacitance are acquired by FEA. A Spice simulation result shows as high as 97% efficiency provided by the proposed shielded-CPT. With misalignment conditions from 1 cm to 3 cm, the system could have managed the efficiency from 85% to 74% in the Y-misalignment direction, and drop to 48% when the coupler is in the X-misalignment direction.