A Self-Oscillation WPT System With High Misalignment Tolerance

High misalignment tolerance is vital in the application of wireless power transfer (WPT) system. In this article, a self-oscillation WPT system with high misalignment tolerance is presented. Under the condition that the compensation equation is satisfied and the input impedance is pure resistance, the output of the S/PS topology WPT system is independent of the coupling coefficient. This article adopts the self-oscillation control method to ensure that the input impedance is pure resistance, so that the fluctuation of the system output is small with the change of the coupling coefficient. Moreover, a parametric design method that can satisfy the design requirements of transmission distance, misalignment, and output voltage is proposed. To deduce the analytical solution of the proposed WPT system, an equivalent coupled-mode method is presented in this article. Finally, the experimental results indicate that when the distance is 20.0 cm and the misalignment is less than 14.9 cm, the output voltage and efficiency of the system remain almost unchanged.