Increasing power level of resonant wireless power transfer with relay resonators by considering resonator current amplitudes

摘要

Resonant wireless power transfer (RWPT) has been widely studied in recent years. In this paper, a descriptive approach of the circuit theory with normalized resistance is proposed and applied to the analysis of relay resonators using four important factors: the source matching factor, the load matching factor, the transfer quality factor, and the reflected impedance factor. The explicit closed-form expressions of currents and efficiency in the general n-resonator RWPT system are deduced. Maximum efficiency can be obtained at a particular load resistance, but the resonator currents may differ greatly. For identical relay resonators, the resonator currents should be equalized in order to achieve the highest system power level. Uniform current distribution and uniform spacing distribution with equal reflected impedances are analyzed. The latter is proved to achieve approximately equal currents and relatively high efficiency.