Frequency tracking and tuning control of wireless power transfer system

Abstract

Abstract A tuning control method with frequency tracking function is proposed to improve the degradation of efficiency caused by coil detuning in magnetically-coupled resonant wireless power transfer. Firstly, the detuning mechanism is studied by combining the AC impedance characteristics of the series resonant circuit, and the feedback control circuit is constructed by using a modified phase-locked loop, which outputs a variable frequency PWM wave to regulate the operating frequency of the high frequency inverter and maintains the phase difference between the inverter output voltage and the original side current within the error range. The Matlab/Simulink simulation results show that the design can successfully transfer the system to a new resonant state with short regulation period and high control accuracy, which can effectively improve the transmission efficiency and load power of the system.