Research On Frequency Tracking Control Of Magnetic Resonance Radio Energy Transmission System

With the increasing application of electric energy,the transmission of electric energy through wireless transmission is gradually favored by human beings.From common facilities and equipment to aerospace and underwater application equipment,radio energy transmission technology has been better developed.Compared with the traditional power transmission,the advantages of radio energy transmission are that the power supply equipment and the power consumption equipment do not need to contact directly to avoid the problems caused by wear,sparks,plug and plug,etc.the disadvantage is that the transmission performance is not as good as the traditional wired power transmission,and it is easy to be affected by the environment.In order to solve the problem of low efficiency of radio energy transmission,this paper adopts the magnetic resonance radio energy transmission mode and adds the frequency tracking technology.The magnetic resonance type radio energy transmission mode can realize the high-efficiency transmission of electric energy in medium distance,and the frequency tracking technology can realize the frequency self-locking to solve the problem of possible detuning due to the long-term operation of the system.The main research contents of this paper include the following aspects:First of all,according to the mechanism of MRR radio energy transmission,the theoretical circuit model is established,the structure topology of inverter circuit and resonance compensation circuit is studied,and the characteristic relationship between the loop current of receiving and sending end,the transmission power and efficiency of the system and the working frequency,load size,transmission distance and coupling coefficient of the system is deduced.Secondly,using MATLAB simulation,the paper analyzes the influence of the inductance value,working frequency,transmission distance and load change of the receiving and sending coil on the system characteristics,determines the relevant parameters of the system,and uses Simulink simulation software to build the system simulation platform,and measures the relevant data to compare and correct the theoretical derivation parameters,laying the foundation for the hardware platform.Thirdly,using Verilog HDL language to program each module of frequency tracking digital PLL,and design the related hardware circuit based on FPGA.Compared with the traditional analog PLL,digital PLL based on FPGA has the advantages of easy modification,wide application and little influence by externalfactors.The digital phase-locked loop technology realizes the real-time tracking control of the inverter output frequency,and keeps the system working frequency consistent with the resonant frequency.Finally,the physical platform is built according to the simulation parameters.This paper introduces the theoretical model building and derivation,high frequency inverter,resonance compensation,AD sampling,Bluetooth transmission,PLL frequency tracking.Some important components and parameters are described.The results of many tests on the system show that the transmission efficiency of the MRR radio energy transmission system can be improved by about 20% compared with the constant working frequency mode after the introduction of frequency tracking technology.It shows that the frequency tracking technology based on DPLL can effectively improve the transmission performance of the system.