Design of a Static Capacitive Power Transfer System With Six-Plate Coupler for Electric Vehicle Wireless Charging

This article proposes a novel six-plate arrangement to improve the mutual capacitance, power transfer level, and efficiency of the static capacitive power transfer (CPT) system. The proposed vertical arrangement reduces the size and weight of the coupler compared to the conventional horizontal arrangement. The transmitter or primary side consists of four aluminum plates and the remaining two plates with mica placed in the receiver or vehicle side. The two vertical transmitter plates are placed on the outer side with a 300 mm gap, while the remaining four plates are installed between the outer plates with a 60 mm air gap. Thirteen coupling capacitances are created between these six plates to maintain strong coupling, which is reduced to four coupling capacitances after calculation. Finite element analysis (FEA) is carried out using ANSYS Maxwell simulation to determine the plate dimensions and coupling capacitances, and the simplified circuit model is simulated in LTspice. The power transfer level of the proposed system is experimentally verified at a transmitter distance of 300 mm (distance between outer plates) with an output power of 6.06 kW and an efficiency of 92.3% at a 60 mm air gap.