Inductive characteristics of different coupling setups for wireless charging of an electric city-car

Inductive Wireless Power Transfer (WPT) is advantageously used to charge the battery pack of the electric vehicles (EVs). The key component of any inductive WPT system is the coupling setup of the two coils, one buried in the road pavement and the other one embedded into the EV, since it plays an important role in the power transfer. This paper refers to the study case of a WPT system for charging the battery pack of an electric city-car and evaluates the inductive characteristics of different coil-coupling setups. The evaluation begins with a formula-based approach and continues with a computer-assisted analysis of the coil-coupling inductive parameters. The evaluation includes the study of the dependence of the parameters on coil distance, axial misalignment, and turn distance. The outcomes of the analysis are used to compare various coil-coupling setups in view of the implementation of a WPT system in the electric citycar of the study case.