Design of compensation network with variable inductance for wide variation of coupling coefficient in inductive power transfer

Abstract

SummaryIn this paper, a design of the compensation network with a variable inductor is proposed, considering a wide variation of the coupling coefficient in the inductive power transfer (IPT). The characteristics of the proposed compensation network are analyzed with respect to the variable antenna coupling conditions. The realization of the zero voltage switching (ZVS) and the reactive power demand are discussed through the theoretical deduction and numerical simulation. Influence of the variable inductor on the compensation network characteristics is examined in detail, and the control algorithm for achieving the coupling independent constant output voltage is proposed. Detailed steps to design a prototype fulfilling all performance requirements are given. Verification of the proposed method was carried out on the experimental model. Recorded output voltage variation is within 5% over the wide coupling range, implying a quite well characteristic of the coupling independent voltage output. Experimental results match well with the calculations, validating the rightness of the proposed variable inductor tuning method.