Output stability control method for electric vehicle DWPT systems based on interleaved there-level buck converters

With the development of wireless power transfer (WPT), dynamic wireless power transfer (DWPT) has become a key technology for solving the low driving range of electric vehicles. This study aims to alleviate the output fluctuation of the power supply rail of a bipolar transmitter during DWPT, and to meet the wide output voltage range requirement at the receiving end. Specifically, a cascaded interleaved three-level buck converter is developed as a power topology at the receiving end to effectively reduce the electrical stress of the switching device. In addition, a control method that combines active disturbance rejection control and a disturbance observer is proposed to suppress the output fluctuation of the coupling coil at the receiving end and to improve the dynamic response speed, which effectively enhances the output stability of the DWPT system. In this paper, a 30 kW DWPT experimental platform is established to verify the superiority of the cascaded three-level buck converter and the effectiveness of the proposed control method. The proposed control method has a 40% higher fluctuation suppression capability when compared with the traditional control method.