Magnetically Coupled Resonant Wireless Energy Transmission System Based On Impedance Matching Network

Wired charging method is often limited by the length of the wire,whereas wireless charging methods are more widely used.Among them,the Transmission distance of Magnetically Coupled Resonance Wireless Power Transmission(MCR-WPT)is relatively long,non-directional and free from the interference of non-magnetic materials,which has gradually attracted more attention and research at home and abroad.At present,many positive achievements have been made in the research of the working principle,topology design,coupling mechanism optimization,transmission characteristics and other aspects of the magnetic coupling resonant wireless charging system.The transmission efficiency of the system is largely affected by the change of transmission distance and load.This paper designs a magnetic coupling resonant wireless charging system based on impedance matching network through a large number of simulations and experiments.The contents are as follows:Based on the modeling and theoretical analysis of MCR-WPT system,the transmission characteristics of two-coil coupling and four-coil coupling in current wide application are analyzed and studied in detail.The control chip of high frequency power supply uses DSP and CPLD combination,and the generated PWM wave acts on the Si C switch tube of double E class inverter through the high-speed drive chip,and at the same time,the resonant frequency is closed loop adjusted.Under the premise of soft switching control,the high frequency inverter of MHz level is completed.After the frequency splitting phenomenon in MCR-WPT system is studied,a method of impedance matching using DC-DC converter is designed,that is,the up-down voltage converter is embedded between the load and the receiving device,and the equivalent input resistance of the system is controlled by adjusting the duty ratio of two switches.After building a MATLAB simulation model and verifying the impedance matching method,Lab VIEW was used to establish the monitoring interface of the system,and the data communication was carried out.The correctness of the design was verified by the experimental platform.