Research And Design Of Resonant Wireless Charging System

Wireless power transfer(WPT)is a new technology that transmits electric energy through non-contact mode.It is safe to operate and convenient to use.In recent years,it has received high attention,and its application range is becoming more and more extensive,such as home appliances,robots and other fields.Although radio energy transmission has many advantages,the low transmission efficiency of electric energy has always been an important reason restricting the development of wireless charging technology.The content of this paper is to realize the efficient transmission of electric energy in wireless charging system.The radio energy transmission mode used in this paper is magnetic coupling resonance wireless charging mode.Through the analysis of the mathematical model of magnetic coupling resonance wireless charging system,it is found that when the system is detuning,it has a great impact on the transmission efficiency.Through the further analysis of the system detuning mechanism,it is concluded that one of the main factors causing the system detuning is the change of the system working state,which makes the actual resonant frequency of the system deviate from the working frequency of the system.Therefore,properly adjusting the working frequency can maintain the system in the resonant state and improve the working efficiency of the system.The frequency tracking method of digital phase-locked loop based on Adaptive PI control is used to track whether the working frequency deviates from the resonant frequency.At the same time,in order to improve the tracking speed and accuracy of frequency,adaptive fuzzy controller is used to change PI parameters in real time for adaptive adjustment.Finally,the Simulink simulation of the resonant wireless charging system designed in this paper shows that this method can greatly improve the tracking speed and tracking accuracy,and effectively improve the transmission efficiency of the magnetic coupling resonant wireless charging system.Based on the research of simulation experiment,the hardware circuit of the system is designed,and the software design of the system adopts modular programming.Finally,a resonant wireless charging system with power of 300 W is built for experimental verification.By changing the load resistance and coil distance of the system,the system without frequency tracking and the system with frequency tracking are tested respectively.The results verify that when the resonant wireless charging system based on Fuzzy PI control PLL frequency tracking is used,the resonant state of the system can be maintained quickly and accurately when the system is detuning,and the transmission efficiency of the system is improved.The experimental results show that this design scheme can achieve the expected design goal.