Maximum Efficiency Tracking of WPT System Based on Frequency Tracking Control

The parameter variations of magnetically coupled resonant wireless power transmission (MCR-WPT) system cause frequency splitting and resonant frequency shift, which lead to the system detuning and reduce the transmission efficiency. To solve the problems, a frequency tracking control method based on the phase difference between the primary-side voltage and the secondary-side current (Frequency Tracking Control-the primary-side voltage and the secondary-side current, FTC-PS) in this paper. According to the characteristics that the phase difference between the voltage of transmitting side and the current of receiving side is not affected by frequency splitting, the phase difference is controlled at 90°, so that the system can achieve the maximum transmission efficiency under the condition of frequency splitting and resonant frequency shift. The experimental results show that the method can make the system always work at the natural resonant frequency when the parameters change, and the transmission efficiency is not affected by the frequency splitting phenomenon. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.