Low Frequency Wireless Power Transfer using Optimal Primary Capacitance of Parallel Resonance for Impedance Matching

Abstract

Wireless Power Transfer (WPT) has been widely studied for decades by using the Series Resonance (SR). Most of the resonant frequency is in a range of 200 kHz -13.56 MHz. Additionally, a pure resistive load is commonly adopted for simplifying a design under Impedance Matching (IM) condition. However, there are usual problems presented in the past studies. For example, i) common electrical loads are complex, so the SR structures are difficult to be designed for achieving the IM condition, ii) the resonant frequency in this range causes several problems, e.g. the tissue absorption on humans, electromagnetic interference, etc. In this paper, we propose the method to design the Parallel Resonance (PR) using an optimal primary capacitance for achieving the IM condition, which can operate at a low frequency, as 15 kHz, at a complex load.