A Hybrid Compensated Wireless Power Transfer System with Quasi-Constant Output Power against Load Variations

This paper proposed a new hybrid compensated wireless power system that provides a relatively constant output power profile under the load variation situation. Two different frequency selective compensation networks are developed for the characteristic combination of series-series and series-parallel compensation networks. By utilizing the fundamental and third harmonic voltage components of the phase-shift-controlled inverter, the proposed system could simultaneously exhibit both output characteristics of constant current and constant voltage at different frequencies. Based on the compensative effect against the load variation, the output power can be maintained almost constant at a certain load range. The theoretical analysis proves the feasibility of the proposed system with the support of the Superposition Theorem. A down-size prototype is developed for verification. The experimental results show that the system achieves an approximately constant output power of 40W when the load varies from 20 to $65 \Omega$ with a maximum power fluctuation of 4.76%.