Low frequency wireless power transfer using modified parallel resonance matching at a complex load

摘要

Series resonant and strong coupling structures under an impedance matching (IM) condition of wireless power transfer (WPT) have been widely studied. These operate under an optimal resistive load and high resonant frequency of greater than 1 MHz. However, the optimal parameters (particular values) limit the design. The common loads are complex and the high frequency RF sources used are usually inefficient. This paper presents a modified parallel resonant (PR) structure that can operate at a low frequency of 15 kHz without an optimal parameter under an IM condition with a complex load. The calculated and experimental efficiencies for a 5?cm transfer distance were 71.2 % at 15 kHz and 68% at 17 kHz, respectively. Hence, a modified two-coil PR structure can be operated at a low frequency with high efficiency.