Analytical modeling of wireless power transfer (WPT) systems for electric vehicle application

This paper presents an analytical model for wireless power transfer system used in electric vehicle application. The equivalent circuit model for each major component of the system is described, including the input voltage source, resonant network, transformer, nonlinear diode rectifier load, etc. Based on the circuit model, the primary side compensation capacitance, equivalent input impedance, active / reactive power are calculated, and the model provides a guideline for parameter selection. In addition, the voltage gain curve from dc output to dc input is derived as well. A hardware prototype with series-parallel resonant stage was built to verify the developed model. The model was validated by comparing the experimental results from the hardware prototype.