Design and Efficiency Optimization of a High‐Power Capacitive Power Transfer System

ABSTRACT The demand for high‐power wireless power transfer (WPT) systems has been increasing in recent years. However, most of the available research works on high‐power transfer are focused on inductive power transfer (IPT) systems. Compared with IPT, capacitive power transfer (CPT) offers advantages such as light weight, low cost, and simple structure. In this paper, the design and efficiency optimization method of a high‐power CPT system is proposed. Firstly, an input‐parallel output‐parallel (IPOP) multi‐channel topology is established for high‐power CPT systems, and the transmission characteristics are analyzed. A multi‐channel coupler with shielding plates is designed, and the equivalent circuit model of the coupler is developed based on the induced current source model. Then, the factors affecting efficiency are investigated, and an optimization method is proposed to enhance the overall system efficiency. Finally, an experimental platform of a 10‐kW IPOP three‐channel CPT system is built. Experimental results show that the output power is three times that of a single‐channel CPT system, with a dc–dc efficiency of 94.2%. The correctness and effectiveness of the design and optimization method are validated.