Study Of Circuit Topology On Simultaneous Wireless Power And Information Transmission Based On Unsymmetrical Current Waveforms

The wireless power transfer technology has experienced rapid development in the past two decades and has already highlighted its broad application prospects in the field of power transfer.Inductive wireless power transfer technology is widely used in the fields of human implantable devices and electric vehicles for its advantages of small radiation,flexibility,and no direct contact.In some special occasions,in addition to realizing power transmission,a synchronous transmission of signals is also required.This paper proposes that harmonic amplitudes is adjusted by changing the duty ratio of the inverter,as a means to encode information through the same wireless power channel.The fundamental and harmonic components can be used for power and information transfer respectively by duty ratio control.In this paper,inductive power transfer is investigated firstly.The system equivalent circuit model based on mutual inductance model is established.The basic principles and structures and main system parameters of it are investigated by formulas.Then,Interference between power and signal is Fullly considered,and a new solution by adjusting harmonic amplitudes to realize WPIT is proposed.Based on the solution,theoretical studies are carried out on the transmission circuit topologies suitable for the solution.These transmission circuit topologies include flyback inverters,dual-tube forward inverters and active clamp forward inverters.Fourier decomposition of unsymmetrical voltage Waveforms generated by the inverter is conducted to get the mathematical relationship between duty ratio and the harmonic components quantitatively.Then,an active-clamped inverter(ACI)is taken to analyze the harmonic communication method based on duty ratio.Finally,the hardware experiment platform is designed based on ACI.The experiment results show that the proposed solution effectively reduces the influence of communication function on the transmission efficiency.The proposed method can achieve the quasi-decoupling relationships between communications and efficiencies.At the same time,the signal-noise-ratio(SNR)of the system transmission is improved,and two communication methods developed can balance the power transfer capability and signal-noise-ratio(SNR)when the complexity of communication is reduced.