A Data-Driven Control Method for Nonlinear Characteristics of Variable Frequency Regulation for Wide-Distance-Range Adaptive WPT System

In the realm of output control for wireless power transfer (WPT) systems, variable frequency (VF) regulation of the transmitter inverter stands out as a leading and sophisticated research direction, as it facilitates the adjustment of the voltage conversion ratio and holds significant promise for long-distance power transfer applications. However, the VF regulation process in WPT systems is characterized by strong nonlinearity and is highly sensitive to variations in the inverter driving frequency. In addition, increasing transfer distances exacerbate these nonlinearities due to changing mutual inductances. Consequently, traditional approaches to VF regulation are constrained by a limited operating range, which impedes the application of WPT technology in scenarios involving varying distances. To address these challenges and enhance the system's adaptability to different power transmission distances while managing multiparametric uncertainties in WPT systems, this article develops a data-driven model-free adaptive control (MFAC) method. Initially, an online modeling approach utilizing dynamic linearization is proposed to characterize the VF regulation process using solely system input–output data. Subsequently, a switched control strategy based on the estimated data model is devised to calculate the optimal operating frequency for the WPT system. Finally, a prototype with maximum output of 3.88 kW is constructed to demonstrate the feasibility of the proposed approach. The results indicate that the data-driven control system exhibits a robust dynamic response and strong resilience across varying transfer distances ranging from 5 to 65 cm, corresponding to a distance–diameter ratio of 0.125–1.625.