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 (TM) 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 (TM) software from Infolytica (TM). 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.