Detuning analysis and power tracking of dual‐ended resonant circuit based on improved variable‐step perturbation observation for wireless power transfer system

A power tracking method based on improved variable‐step perturbation observation approach has been proposed in this paper. This method is aimed at addressing the detuning issues caused by capacitor parameter drift in MCR‐WPT systems based on S‐S compensation circuits. Compared with traditional tuning methods, the proposed method has fast response, high accuracy, low complexity, and less prone to over‐tracking. Firstly, a mathematical model of the system based on the detuning factor has been established. Secondly, the impact of different detuning conditions on the system at the initial resonant frequency has been studied. Thirdly, the response characteristics of the system to different frequencies under different detuning conditions have been studied. Fourthly, based on the above researches, an improved variable‐step perturbation observation method based on the single‐step power drop factor has been proposed. Finally, an experimental platform was constructed, and relevant experiments were conducted. Experimental results validate the effectiveness of power tracking under different detuning conditions, with the lowest transmission efficiency being 81.51%.