Influences of Spurious Conductors on Long Distance Inductive Power Transfer Systems

An explicit model of inductive power transfer system (IPTS) that precisely accounts for the influences of arbitrarily distributed conductors surrounding the IPTS is newly proposed in this paper. When time-varying magnetic flux is applied to the conductors, eddy currents in the conductors not only change the characteristics of the IPTS but also deteriorate the maximum power transfer of it. Because of these effects, the primary resonant frequency of a typical experiment system is changed up to 2.11 % from the operating frequency of 19.89 kHz, and the measured primary referred resistance R_s changed from 1.49 Ω to 1.65 Ω, where the load power of the IPTS increased about 5 %. The proposed model is found to be quite useful for a long distance IPTS, which inevitably interacts with the unwanted spurious conductors.