Research On Frequency Tuning Method Of ICPT System Based On Push-pull Topology

In real life,most power supply mode of electrical equipment owned by humans is powered from the grid.However,this direct contact of device will have a great impact on the flexibility,and there are still some security risks.In order to solve the flexibility and safety of electrical equipment access to these electrical equipment,Wireless Power Transfer(WPT)technology is generated.Inductively Coupled Power Transfer(ICPT)technology is a relatively mature research direction in the field of Wireless Power Transfer technology.However,there are still many problems worthy of further research for ICPT system.In this paper,the problem that the reflection impedance of the primary circuit is affected by the change of the system load,which affected the inherent resonance frequency of the primary circuit is studied.If the inherent resonant frequency of the primary changes,which is inconsistent with system's operating frequency.Then will not only lead to system's energy transmission capacity and transmission efficiency reduction,but also cause the output voltage instability.Therefore,it is necessary to analyze the factors that affect the inherent resonant frequency of the primary circuit of ICPT system,and using reliable control strategy to ensure the stability of the inherent resonant frequency of the primary side.Thus improving the power transmission capacity and system efficiency,ensuring the stability of system output voltage,and system can be reliably powered.In this paper,the research status of ICPT system at home and abroad is discussed,the tuning control research of ICPT system is analyzed,and the basic structure and working principle of ICPT system are briefly introduced.Then,the basic topology of ICPT system and its commonly used tuning control method are analyzed.A tuning circuit with variable capacitance is designed in the primary circuit.The circuit is analyzed theoretically by using the phase shift control strategy.The phase shift control strategy is used to control the variable tuned capacitor in the system,so as to ensure that the resonant frequency of the primary circuit is relatively constant and the output voltage is relatively stable.Aiming at the designed tuning control ICPT system,the whole simulation model of the system is built on the Matlab/simulink simulation platform,and the corresponding simulation analysis is carried out.The result shows that when the variable tuning capacitance value changes within a certain range,the resonant frequency of the primary circuit can be kept relatively constant and the output voltage can be relatively stable by proper tuning control.Finally,the experimental experiment is carried out.The control circuit of the variable tunable capacitor is designed with the FPGA control chip.The system circuit is composed of the main circuit,the driving circuit,the detection circuit and the rectified output circuit.The theoretical analysis as well as the simulation are vivificated by specific experiments.The experimental results show that this method has a good control effect on the resonant frequency and the output voltage of the primary circuit.