Modeling and Control of WPT Systems in the Presence of Load and Mutual Inductance Variations
Shijun Zhao, Fengwei Chen, Chunsen Tang, Pengqi Deng, Chanzhen Duan
Abstract
The low-order Hammerstein model plus time delay has been a popular option to describe the dynamic behavior of a wireless power transfer (WPT) system. The controller designed based on this model can achieve better set point tracking performance in a computationally efficient way. Furthermore, load and mutual inductance variations are quite common in WPT systems and they will impair the modeling accuracy and control performance if one has not been taken into account. To address this problem, this article proposes a combined internal model control (IMC) and Luenberger disturbance observer (LDO) method to achieve enhanced disturbance rejection performance against load and mutual inductance variations. Specifically, a data-driven method is employed to build the system model, then the IMC-based method is proposed for controller design, in which LDO is combined to observe and eliminate the disturbances. To ensure the stability of the closed-loop system, a pole placement method is suggested to properly design the observer gain. Thanks to the LDO that can accurately estimate the disturbances resulting from load and mutual inductance variations, the IMC controller can rapidly track the set point irrespective the disturbances. Finally, simulation and experimental results are provided to validate the effectiveness of the proposed method.