Comprehensive design comparison of using different order harmonics as the power carrier in wireless power transfer for PHEV and EV wireless charging

A series resonant converter (SRC) with third harmonic as the power carrier has been verified with the benefit of reducing the resonant components to one third. With proper design, it can have competitive efficiency with that using fundamental power, while the size and weight are much smaller. However, there is a trade-off between using a higher order harmonic and the larger current stress on the primary side. In this paper, a comprehensive design comparison of using different order harmonics as the power carrier in wireless power transfer for plug-in hybrid electric vehicle (PHEV) and electric vehicle (EV) wireless charging is presented. The comparison mainly focuses on overall efficiency and each component's stress. A guideline for choosing the optimal order or harmonic as power carrier is discussed after the comparison. A 1-kW prototype with 20-cm air gap using harmonic power is built to verify the proposed method.