Quick Estimation of Coupling Coefficient in an Electric Vehicle Wireless Charging System

Wireless charging of Electric Vehicles (EVs) is becoming popular as it mitigates issues such as handling heavy cables, safety risks in harsh weather, and vandalism. It also matches wired efficiency in the present day. Estimation of coupling coefficient requires time-consuming finite element method (FEM) simulations, and this paper presents a quick, real-time method for estimating it for a 11-kW wireless charging system for EVs. This approach uses obtained FEM simulation data which is fitted with curve-fitting polynomial equations and further post-processed to estimate the coupling coefficient, mutual inductance and power transfer efficiency. Experimental measurements confirm the accuracy of this method, offering a time-saving solution for the initial developmental phase of EV wireless charging systems.