The Design And Manufacture Of High Frequency Power Supply For Wireless Group Charging System

With the continuous development of science and technology and the improvement of people's living standards,the functions of portable electronic products such as smart phones are becoming more and more powerful,so the charging requirements are also higher and higher.Due to some limitations of traditional charging methods,the Magnetically-Coupled Resonant Wireless Power Transfer(MCR-WPT)technology has been proposed since 2007.At the present stage,the principle,coil coupling mode and transmission performance of the MCR-WPT are studied extensively and deeply.However,few researches have been devoted to the high frequency power supply in the system.Therefore,it is necessary to design a reliable high frequency power supply which can meet the MCR-WPT,and it has a positive role in promoting the popularization of radio energy transmission technology.Firstly,the whole structure of the MCR-WPT is analyzed in this paper,and the equivalent circuit model of the system is established,thus the load characteristics of the high frequency power supply in the system are determined.By comparing and analyzing the basic principle,working efficiency and applicable occasions of Class A-F power amplifier,a scheme of designing the high frequency power supply by using Class E power amplifier is proposed.This paper also describes the design method of Class E power amplifier,and according to the design index of the power supply output power of about 25W at the frequency of 6.78MHz,the Class E power amplifier and the impedance matching circuit are designed and simulated.In addition,the corresponding drive circuit of MOS is designed,and the whole high frequency power supply is simulated.In order to further analyze the impedance adaptability of the designed high frequency power supply,the simulation of the circuit under three different loads is given at last.The simulation results show that the output power of the high frequency power supply can reach about 25W by adjusting the magnitude of the input DC voltage at different loads,which meets the design requirements.In order to verify the correctness of the theory and simulation,this paper also designed a PCB board for high frequency power supply,and finally the high frequency power supply is measured and debugged.The experimental results show that the designed high frequency power supply can meet the output power requirements of about 25W under 6.8MHz when the load changes of 5? 2?50 ?,and the design goal of the high frequency power supply is achieved.Finally,the designed high frequency power supply is applied to the MCR-WPT system,and the system works in good condition.