Research On A GaN-based Simultaneous Wirelsss Information And Power Tranfer System Using Double Frequency PWM

Implantable medical devices have made great contributions to help people treat diseases,relieve pain and enhance the function of human devices.However,due to the limited charging,discharging times and the short service life of the lithium battery,the normal use of this equipment will be affected.Therefore,aiming at the problems of power supply of implantable medical devices,combined with the advantages of wireless power transfer(WPT)technology,this paper designs a coupled resonant dual frequency wireless power and information transmission system based on GaN devices.The main work of this paper is as follows:Firstly,a dual frequency pulse width modulation(DFPWM)strategy is proposed,which can use a single inverter to output two frequencies,which can realize the simultaneous wireless power and information transmission.By establishing the mathematical model of this proposed control strategy,the corresponding constraints are obtained,and then,the intelligent algorithm is used to get the release angle that meets the constraints,so as to complete the preparation of the control strategySecondly,a GaN-baned simultaneous wireless power and information transmission system using DFPWM is designed.The system realizes bidirectional information transfer without additional high frequency signal source.By parallel a MOSFET at the output port,a voltage chopper circuit is constructed.The constant output voltage is realized by adjusting the duty cycle of the parallel MOSFET.In order to realize information transmission of the proposed WPT system,the forward and backward information transmission channels are constructed in primary side and secondary sides,respectively.The corresponding mathematical model is established for each information transmission channel.The gain and interference of the transmission channel are analyzed in detail,and the corresponding information demodulation scheme is designedFinally,an experimental platform is built to verify the proposed control strategy and system structure.Comparing the experimental results of forward and backward information transmission under different control strategies,the system achieves constant voltage output with a maximum output power of 10W when the coil spacing is 10cm Moreover,the maximum forward information transmission rate of the system is 42.5 kbsp and the maximum backward information transmission rate is 20 kbps.The feasibility and effectiveness of the theoretical analysis are verified.The prototype platform verifies the feasibility of wireless power transmission technology in implantable medical devices,and provides a theoretical and experimental basis for the practical application of the prototype.