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, steadystate 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, 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.