Identification and H$\infty$ Robust Control of Wireless Power Transfer System by Hammerstein Model

In the field of control-oriented modeling of wireless power transfer (WPT) system, it is urgent to establish a simple model to reflect the nonlinear characteristics introduced by phase-shift control methods, which is significant to the design of controllers. Due to the nonlinear nature introduced by phase-shift control, controllers designed based on specific steady-state small-signal models struggle to maintain closed-loop dynamic performance. In this paper, the nonlinearities of the WPT system are implicitly considered by using the Hammerstein model-based identification (HMI) method, so the accuracy of the identified model is guaranteed even if the working point changes, which is unique advantage compared to other methods. In particular, an uncertainty model is precisely established via a frequency-domain analysis approach to introduce the nonlinear characteristics and the statistical properties of identification into the H $\infty$ control problem, which maintains the robustness of closed-loop WPT system. Finally, an experiment is given to verify the effectiveness of HMI method and proposed H $\infty$ robust controller.