Modelling approach for low-frequency strongly coupled magnetic resonance wireless power transfer system

This work describes the characterization of a three coil system presenting strongly coupled magnetic resonance (SCMR) at low frequency. A theoretical model for the power transmission efficiency between coils is studied, in order to predict the system behaviour, for different positions of the auxiliary coil placed in the middle of the transmission. The best approach for determining each parameter that impacts the performance (inductance, coupling coefficients and quality factor) is found for this low-frequency system. The power transfer efficiency of a typical two coil system is increased 270 times by adding an optimized auxiliary coil in the middle. Theoretical models and experimental measures are in good agreement.