Five-Plate Coupler for Single-Side Shielding Applications in Capacitive Power Transfer

This paper presents a novel five-plate capacitive coupler consisting of four power transfer plates and one shielding plate. It is designed for single-side shielding applications, such as wireless charging for electric ships. To achieve accurate modeling and analysis, a full-capacitance model of the five-plate coupler is proposed and then simplified into a two-port model. Finite element analysis results demonstrate that the equivalent capacitance of the five-plate coupler follows a similar trend to the four-plate and six-plate couplers, with comparable capacitance values. Additionally, the five-plate coupler achieves effective shielding of the receiving side electric field while utilizing one less shielding plate compared to the six-plate coupler. A 3-kW prototype is constructed to validate the high-power and high efficiency wireless power transfer capability of the proposed coupler, achieving a DC-to-DC efficiency of 94%. The five-plate coupler offers cost savings and simplifies the design process while ensuring electrical field safety requirements are met.