Study Of Near-Field Coupled Wireless Power And Information Transmission Technology Based On The Triangular Current Waveform

With the increasing applications of intelligent electronic products,wireless power transfer technology gains more attention.Wireless power and information transmission(WPIT)technology can realize simultaneous wireless transmission of power and information.It’s of great significance in reducing the size and cost of the whole system.In this paper,a new method is proposed to realize WPIT which uses the triangular current waveform as the excitation of the multiplexing system based on electromagnetic coupling.The fundamental component of the triangular current waveform is employed to transfer power,and its third-order harmonic component is selected to transfer information.First of all,inductive power transfer is investigated in this paper to show the basic principles and structures of it.By analyzing the basic topology of the system,the influence of each parameter on the performance of the system is studied.Then,a new solution to realize WPIT is proposed.Fourier decomposition of triangular current is conducted to get the mathematical relationship between the fundamental and the 3rd-order harmonic component quantitatively.The equivalent circuit model of the multiplexing system is put forward.The theoretical analysis of the model is made to show the influence that the coupling relationship between coils has on the system performance.The effect that different physical positions of the signal receiving coil has on the signal-to-noise ratio(SNR)of communication is investigated.Harmonic components have an enlargement effect to the deviation of the fundamental frequency,this feature is used to realize the weakly coupled control between the information transmission and the efficiency of wireless power transfer.Based on the proposed harmonic communication method,the transient process and the maximum communication speed of the circuit are discussed.Finally,hardware experiments platform is designed based on the coil coupling model and 2FSK modulation strategy to verify the correctness of the theoretical analysis.Experimental results show that the proposed method can alleviate the effect of data transmission on the efficiency greatly.Therefore,this paper can provide a new solution for designing the WPIT system.