Highly integrated hybrid inductive and capacitive power transfer system with asymmetrical printed-circuit-board-based self-resonator

Abstract

This paper presents a highly integrated and compact hybrid wireless power transfer (WPT) system with asymmetrical printed-circuit-board (PCB) based self-resonators. The PCB-based self-resonant coupler consists of four PCB-coil plates with two different sizes, which can work as the transmitter/receiver for IPT as well as the capacitive plates for CPT. With a typical stacked four-plate configuration, both inductive and capacitive mutual couplings are achieved between transmitter and receiver, contributing to a highly compact and integrated self-resonant hybrid WPT system without any external compensation components. Detailed theoretical analysis and system modeling are provided based on the two-port parameter theory and a 300W hybrid WPT prototype is implemented with an asymmetrical coupler consisting of 210-mm and 140-mm PCB-coil plates. The implemented hybrid WPT system is tested at 80mm, 60mm, 37mm, and 12mm with self-resonant working frequencies of 3.845MHz, 3.75MHz, 3.57MHz, and 3.19MHz, respectively, and the system performance in terms of output current property, power transfer capability, DC-DC efficiency, and misalignment tolerance are evaluated in details, which demonstrate a peak DC-DC efficiency of 87.3% with 155.7W at 12mm and 86.7% with 237.5W at 37mm, validating the effectiveness of the designed hybrid WPT system.