Design And Implementation Of Wireless Power Transfer System Based On Improved Class E Power Amplifier

Compared with wired power transmission technology,the wireless power transmission technology has the advantages of convenience,security and reliability,solving the potential problems of wired power transmission technology,such as wiring aging,damage and wear,so the research on wireless power transmission technology will have broad application prospects and some electronic products on the market use wireless energy transmission technologies,such as electric toothbrushes,mobile phones and other electronic products.However,there are still some shortcomings in the current wireless power transmission technology.For example,the change of distance and load has a great influence on the efficiency and output power of wireless power transmission.In this paper,the improved class E power amplifier can can reduce the sensitivity of the load.the research frequency tracking can reduce the frequency offset of the system and improve the transmission efficiency,which has theoretical significance and engineering research value.Firstly,this paper expounds the background and significance of wireless power transmission technology,then Introduces the research status of magnetic coupling resonant wireless power transmission technology,and determines the improved E-class power amplifier and frequency tracking strategy as the high-frequency inverter and software control strategies of the wireless energy transmission system respectively.Secondly,while analyzing the basic principle of the magnetically coupled resonant wireless power transmission system,the relationship between the distance and the load and the output power and transmission efficiency of the system is analyzed in detail,and the principle and control strategy of the frequency tracking are analyzed,and then analyzed he frequency splitting phenomenon that the system encounters during transmission.Subsequently the basic principle and parameter design of the improved class E power amplifier are introduced,and the transmission performance and wide load characteristics of the improved class E power amplifier are verified by Saber simulation software.Finally,the system is simulated and the difference of the transmission performance between the two strategies,one of which add frequency tracking strategyand the other do not,is analyzed.Then,the digital control wireless power transmission system with TMS320F28035 as the control chip is designed.The device selection of the improved class E power amplifier and compensation network,as well as the sampling and conditioning circuit,the drive circuit,the RS485 serial communication circuit and the auxiliary power supply are designed.The design of the host computer and modbus protocol,the design of digital PID and the implementation of frequency tracking control.Finally,based on the above analysis,a 10 W magnetically coupled resonant wireless power transmission system prototype is built.The prototype experiments without adding and adding the frequency tracking strategy were tested separately.The difference between the both was obtained by analyzing the data of both,which provided meaningful guidance for the next step.