Phenomenon, Modeling, and Analysis of Transient Power Impacts and Oscillations in Fast-Moving Dynamic Wireless Power Transfer System

Abstract

Unlike the phenomenon where the transfer power of dynamic wireless power transfer (DWPT) systems synchronously changes with the coupling coefficient under low-speed conditions, as the vehicle speed increases, DWPT systems exhibit transient issues such as power instantaneous impacts and sustained oscillations. These excessive power impacts and oscillations will not only demand capacities several times the rated power for the converters and compensation networks but also lead to system instability, stress overloads, and device damages. Currently, to the best of the authors’ knowledge, the mechanisms of the transient power impacts and oscillations in fast-moving DWPT systems are not reported. Thus, this article established a dynamic model for the fast-moving DWPT system to describe its dynamic response. Based on the analysis of the system transfer function and frequency response, the power impacts and oscillations can be quantified by equating the vehicle speed to the input frequency of the system transfer function. Then, a circular experimental prototype for the fast-moving DWPT system has been built to verify the correctness and accuracy of the theoretical analysis. The experimental results with different vehicle speeds exhibit good agreement with the established model and analysis conclusion. Finally, the mechanisms of the transient power impacts and oscillations in fast-moving DWPT systems are clarified.