Low-Cost Single-Switch Bidirectional Wireless Power Transceiver for Peer-to-Peer Charging

Abstract

A single-switch bidirectional wireless power transceiver aiming at cost-effective and reliable peer-to-peer charging applications is proposed. The transceiver comprises a single-switch resonant power circuit, a frequency synchronization circuit, and a microcontroller. It can operate in either transmitter mode or receiver mode. As a transceiver, the required number of semiconductor devices is minimized, i.e., only single active switch is used. This makes it easy to implement and is relatively reliable and cost-effective. The bidirectional power flow and dc output regulation are achieved solely by adjusting the phase shift ratio of the control signal. To make the phase shift power control feasible and to secure wide operating range ZVS operation, a holistic design method is provided such that the ac voltage waveforms remain relatively constant and independent of the coupling and the phase shift ratio changes. The operating principles, steady-state and dynamic models, and design considerations are discussed. Simulation and experiments are performed on a prototype based on the design. The results validate the features of relatively constant ac voltage waveforms of the transceiver, the effectiveness of the time-domain model, the ZVS turn on and turn off operations over wide operating power range, phase shift regulated transmission power control, bidirectional power flow, and accurate output regulation.