A General Method to Parameter Optimization for Highly Efficient Wireless Power Transfer

Abstract

This paper proposes a new and general method to optimize a working
frequency and a load resistance in order to realize highly efficient wireless
power transfer. It should be noticed that neither resonant frequency nor
matched impedance maximizes efficiency of wireless power transfer circuit,
in general. This paper establishes a mathematical model of a commonly
used wireless power transfer circuit, and derives a mathematical expression
of circuit efficiency which involves a working frequency, a load resistance and
the other parameters as symbols. This enables us to find the optimal working
frequency and load resistance. The result of this paper is compared with
results by a method based on resonance and impedance matching, and then
clarified by a numerical example.