Research On Power And Signal Transfer Technology With Separate Circuit Loops For ECPT System

Electric-field Coupled Power Transfer(ECPT)Technology utilizes electric-field as power transfer medium and has many advantages such as simple,flexible and low cost coupling mechanism,no eddying effect and low electromagnetic radiation,the ability of transfer power through metal barrier and so on.This makes it received more and more attention from researchers.With the develop of ECPT Technology,in order to improve robustness and efficiency,the power transmitter and receiver need a data communication to realize closed loop control.What's more,There need to send control signal and receive state detection data between sending side and receiving side in many applications.Nowadays,many scholars have done research and proposed solutions about magnetic-field coupled power and signal parallel transfer technology,but the studies about ECPT system is relatively few.In addition,the coupled mechanisms of ECPT system need high frequency and voltage to transfer power effectively,so it needs to consider the higher frequency and system order in power and signal parallel transmission.Based on the features of ECPT system,the paper aims at finding a suitable method for ECPT system to achieve power and signal parallel transfer and carries out research with the purpose of reducing the crosstalk and simplifying the signal transfer channel.After analyzing some general inverter circuits and compensated networks,finally it determines that the system topology is formed by double-sided LC compensated ECPT system and signal plates.And then,it compares three common signal modulation methods to determine the modulation and demodulation strategy and design the circuits.Based on system topology,it builds up system model by equivalent non-linear module.According to superposition theorem,this paper gets two equivalent topology of power and signal,then sets up system mathematical model based on AC impedance method and gives the expression of power transfer gain,signal transfer attenuation and power crosstalk.The influence of system parameters on the transmission performance is analyzed.Combining with demodulation circuit features and system power constraints,an effective system parameters design method which aimed at improving power and signal parallel transfer ability is proposed.Finally,a system simulation model is set up in MATLAB/Simulink software.A set of system parameters is acquired through the parameters design method.The equal topology and system characteristic expressions are verified through simulation model.Then,a experimental device is set up to verify the theoretical model and system transfer characteristics.In the meanwhile,the experimental device realize the power and signal transfer parallel.The results show that the device can realize stable signal transfer with a baud rate in the range of 1.2kbps-370 kbps while the transfer power is 21.68 W.