Switch-On Modeling and Analysis of Dynamic Wireless Charging System Used for Electric Vehicles

This paper presents an equivalent model to analyze switch-on process of dynamic wireless charging system of electric vehicle (EV). In the model, system initial state before switching is considered and the full response is used to describe the switch-on process. First, the system states before and after switching are discussed, and an approximate method is proposed to calculate the initial value of converter dc-side voltage in switch-on unit. Then, equivalent transient sources and system transfer functions are obtained to establish the switch-on model. So, the switch-on process can be described through full responses of the selected currents under the excitation of equivalent sources. Furthermore, the proposed model is verified by a developed dynamic wireless EV charging prototype. Also, switch-on transient characteristics are investigated through discussions on system parameter and vehicle speed effects. Finally, a simple way to select the suitable switching position is provided based on the analysis of switching position influence, and its effectiveness has been validated by experimental results.