Research On Control Technology Of High Frequency Inverter

As a new type of wireless power transmission technology,magnetic coupling resonant wireless power transmission has been widely concerned because its high transmission efficiency and medium transmission distance.The control technology of high frequency inverter is studied in the background of magnetic coupling resonant wireless power transmission,mainly includes the design of frequency tracking,driving and protection circuit.The control technology ensures high frequency inverter efficient and safe operation in application,which has great significance to the development of wireless power transmission.In this paper,the principle and the basic structure of magnetic coupling resonant wireless power transmission are analyzed,and the topology structure of high frequency inverter and power device model are determined,then the structure of wireless power transmission is designed,and control scheme of high frequency inverter is proposed.The principle of frequency tracking circuit-phase locked loop are analyzed in detail,and all digital phase lock loop is achieved by FPGA,which can effectively solve the problem of frequency mismatch.The drive requirements of high frequency inverter MOSFET is analyzed,and driving circuit is designed by FOD3180,then the driving logic control signal generation method is studied to ensure pulse on a bridge has a dead time to avoid short-circuit.By analyzing the causes of over-voltage and over-current,the protection circuit is designed,so power device can be prevented from work exception.Finally the magnetic coupling resonant wireless power transmission experimental platform is set up,so work frequency can track natural frequency of load,as well as control signal is correct,pulse waveform is good.The system achieves wireless power transmission in 1cm~6cm,and efficiency is more than 50%,which verifies the correctness of the design.