Wireless power transfer system

Abstract

This project has demonstrated that 10 kW of power can be transferred between a pair of coils, spaced 70 mm apart by air. These coils are individually wrapped around an H-shaped ferrite core, compensated by the primary-series, secondary-parallel topology to achieve resonance, thereby improving the efficiency of the transformer. The design can be implemented on wireless battery charging systems for electric vehicles where the primary coils would be embedded in the ground while the secondary coils would be housed within the undercarriage of the vehicle.

The power transfer has been validated through the model that has been built and simulated using MATLAB/Simulink based on the design data provided by a Masters student working on the electromagnetic properties and structural design of the transformer and its coils. The Simulink model also employed an energy injection and free oscillation technique to produce the single phase 30 kHz primary excitation current. This control method achieves and maintains the peak of this excitation current at 100 A at steady state to deliver 10 kW to the load connected at the output of the secondary coil.