基于移相调制的无线供电与信息协同传输技术

Based on Phase-Shifted Modulation

该文提出一种基于移相调制的无线供电与信息协同传输技术。通过控制全桥逆变器的频率和移相角,将工作状态分为两种:当系统仅需要无线供电时,移相全桥逆变器的工作频率等于系统一次和二次线圈谐振频率fp,实现无线电能的高效率传输;当系统需要同时进行无线供电与信号传输时,移相全桥逆变器控制频率采用fp/3作为低频通信频率,通过调制移相角实现信号传输,利用其3次谐波频率fp进行高效率无线电能传输。理论上,通信时所选择的工作相位点仅影响基波频率点幅值分量以实现解码,而对实现无线供电谐波频率点幅值没有影响。该技术采用二次侧双谐振回路构造能量接收电路和信号解调电路,可在同一套硬件装置上实现信道复用,实现低频通信信号的传输和无线电能的高效率传输,在海洋等对通信频率敏感的介质条件下具有明显优势。

In order to meet the requirements of power and communication in equipment,simultaneous wireless power and information transmission(SWPIT)technology has developed rapidly in recent years.This method can greatly enhance the abilities of mobility and intelligence for modern electronic devices,especially for implantable medical devices and autonomous navigation equipment.There are many SWPIT solutions for different applications,and different solutions have their advantages,such as communication speed and capacity,and the effect of communication on wireless power transfer.However,for the medium with high conductivity or dielectric constant,a suitable SWPIT solution with low carrier frequency is necessary to reduce the channel power losses.This paper proposes the dual-resonant loops on the receiver side:the wireless power receiving loop with resonant frequency fp and the signal receiving loop with resonant frequency f_(p)/3,respectively.On the transmitter side,a full bridge converter is used to produce a triangular current in a transmitter coil,and the current frequency is controlled by driving signals.Based on the frequency and phase-shifted control,the proposed full bridge inverter mainly contains two states.First state,if the system needs to transfer wireless power only,the working frequency of the inverter is fp.Since the frequency of the fundamental component of the current is also fp and equal to the resonance frequency in the receiver coil,the system has the highest efficiency and power transfer ability.The energy received by the signal loop can be treated as zero.Second state,if the system needs to transfer wireless power and information simultaneously,the frequency of the inverter is f_(p)/3.The fundamental component of f_(p)/3 is used to transmit information,and the third harmonic frequency fp is used to transfer wireless power.Thus,the carrier frequency for communications is f_(p)/3.The power in the third harmonic component is relatively small compared to the first state.Based on the analysis of the proposed method,the phase angles of 0 and 120 are used to modulate the fundamental component.By modulating the phase-shifted angle,the amplitude in the receiving signal loop has a larger value at the angle of 0 than that at the angle of 120.Theoretically,the selected phase angles only affect the amplitude of the fundamental component without affecting the 3rd harmonic component.Therefore,the effect of communication on the fluctuation of wireless power transfer is relatively small.The shortcoming is that wireless power transfer is only 1/3 of full power.The proposed method can realize SWPIT based on the full bridge inverter only.Based on the proposed topology and circuit parameters,the working features of the system under different conditions are discussed.The interference between power transfer and signal transmission is modeled,and the ranges of phase-shifted and the parameters in the signal detection circuit are determined.Since the working frequency of the inverter has a low-frequency carrier for communication,the proposed method has obvious advantages for the high conductivity medium,such as the ocean.